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The ecology and distribution of ptarmigan in western North America Weeden, Robert Barton 1959

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THE ECOLOGY AND DISTRIBUTION OP PTARMIGAN IN WESTERN NORTH AMERICA. ROBERT BARTON WEEDEN A.THESIS SUBMITTED IN PARTIAL FULFILMENT OP THE REQUIREMENTS POR THE DEGREE OP DOCTOR OP PHILOSOPHY i n the Department of Zoology We accept t h i s thesis as conforming to the required standard IHE UNIVERSITY OP BRITISH COLUMBIA i i ABSTRACT The three purposes of t h i s study were to summarize the important features of the habits and l i f e h i s t o r y of ptarmigan (Lagopus lagopus, I. mutus and I . leucurus), to describe and compare some places i n which each species breeds i n western North America and to propose some fact o r s which may influence the d i s t r i b u t i o n of the three species. Ptarmigan are herbivores which show l i t t l e evidence of important s p e c i f i c differences i n d i e t . A l l known populations of leucurus and many populations of lagopus and mutus are non-migratory, although seasonal v e r t i c a l movements may occur. However, some northern populations of the l a t t e r two species show annual migratory movements presumably based on food scar-c i t y . Male ptarmigan defend areas of ground i n the breeding season. Ptarmigan are monogamous and produce only one brood each year. The onset of egg-laying seems to coincide with the i n i t i a l disappearance of snow from p o t e n t i a l nesting s i t e s . In spring each species s e l e c t s areas i n which to breed. Where three species are present on the same mountain, the ranges of lagopus, mutus and leucurus are progressively further above timberline. The segregation seems to be based p r i m a r i l y on features of vegetation form and t e r r a i n . Estimates of height and coverage were used to describe vegetation i n places used by ptarmigan. L. lagopus established t e r r i t o r i e s and nested where clu s t e r s of shrubs from 3-6 feet i n height alternated with i i i openings where plants were less than 1 foot t a l l (or, i f t a l l e r , very sparse); the vegetation was relatively luxuriant, with a wide variety of species. 1. mutus occupied a zone of tundra similar i n vegetation structure but with lower shrubs and a greater proportion of herbaceous vegetation. L. leucurus showed a preference for shrubless alpine areas where plants rarely exceeded 1 foot i n height, and where ledges, boulder f i e l d s and coarse screes provided crevices for shelter. The available evidence suggests that psychologic fac-tors may control habitat selection. It i s proposed that each ptarmigan responds to a set of visual cues which i s peculiar to that species. As a result, the range boundaries of a particu-l a r population may be set by the occurrence of the features of the environment which are important visual cues. Through such habitat selection, each species of ptarmigan may choose auto-matically the environment to which i t i s best adapted. %\\t Pttttarsti]} of Jbittstj Columbia PROGRAMME OF THE FINAL ORAL EXAMINATION FOR THE DEGREE OF DOCTOR OF PHILOSOPHY of ROBERT BARTON WEEDEN B. Sc., University of Massachusetts, 1953 M. Sc., University of Maine, 1955 IN ROOM 3332, BIOLOGICAL SCIENCES BUILDING MONDAY, OCTOBER 5, 1959 AT 2:30 P.M. Facility of Graduate Studies COMMITTEE IN CHARGE DEAN G. M. SHRUM, Chairman I. McT. COWAN V. KRAJINA M. D. F. UDVARDY P. A. LARKIN W. S. HOAR R. W. PILLSBURY S. READ External Examiner: F. Richardson University of Washington THE ECOLOGY AND DISTRIBUTION OF PTARMIGAN IN WESTERN NORTH AMERICA ABSTRACT The three purposes of this study were to summarize the important features of the habits and life history of ptarmigan (Lagopus lagopus, L. mutus and L. leucurus), to describe and compare some places in which each species breeds in western North America and to propose some factors which may influence the distribution of the three species. Ptarmigan are herbivores which show little evidence of important specific differences in diet. All known populations of leucurus and many populations of lagopus and mutus are non-migratory, although seasonal vertical movements may occur. How-ever, some northern populations of the latter two species show annual migratory movements presumably based on food scarcity. Male ptarmigan defend areas of ground in the breeding season. Ptarmigan are monogamous and produce only one brood each year. The onset of egg-laying seems to coincide with the initial dis-appearance of snow from potential nesting sites. In spring each species selects areas in which to breed. Where three species are present on the same mountain, the ranges of lagopus, mutus and lecurus are progressively further above timber-line. The segregation seems to be based primarily on features of vegetation form and terrain. Estimates of height and coverage were used to describe vegetation in places used by ptarmigan. L. lagopus established territories and nested where clusters of shrubs from 3-6 feet in height alternated with openings where plants were less than 1 foot tall (or, if taller, very sparse); the vegetation was relatively luxuriant, with a wide variety of species. L. mutus occupied a zone of tundra similar in vegetation structure but with lower shrubs and a greater proportion of herbaceous vegetation. L. leucurus showed a preference for shrubless alpine areas where plants rarely exceeded 1 foot in height, and where ledges, boulder fields and coarse screes provided crevices for shelter. The available evidence suggests that psychologic factors may control habitat selection. It is proposed that each ptarmigan responds to a set of visual cues which is peculiar to that species. As a result, the range boundaries of a particular population may be set by the occurrence of the features of the environment which are important visual cues. Through such habitat selection, each species of ptarmigan may choose automatically the environment to which it is best adapted. GRADUATE STUDIES Field of Study: Zoology Comparative Physiology Animal Geography Ornithology Wildlife Management .. M. D. F. Udvardy M. D. F. Udvardy I. McT. Cowan W. S. Hoar Genetics K. Cole Oceanography Physical Oceanography Marine Zooplankton ... Forest Ecology Poultry Science G. Pickard G. Pickard Animal Science R. F. Scagel V. J. Krajina J. Biely J. Biely and A. J. Wood P U B L I C A T I O N S Weeden, R. B. 1956. Cover requirements of breeding woodcock in central Maine. In: Investigations of woodcock, snipes, and rails in 1955. Special Sci. Rep. Wildlife #31. U.S. Dept. Interior, pp. 41-42. Westfall, C. Z. and R. B. Weeden. 1956. Plastic neck markers for woodcock. Jour. Wildl. Mgmt. 20(2): 218-219. Weeden, R. B. 1959. Three reviews in Jour. Wildl. Mgmt. 23(2): 250-252. (1) Birds of the Ungava Peninsula. (2) Comparative biosystematics and life history of the nuthatches Sitta pygmaea and Sitta pusilla. (3) Man's role in changing the face of the earth. Weeden, R. B. 1959. A new breeding record of the wandering tattler in Alaska. The Auk 76(2): 230-232. Weeden, R. B. 1959. The birds of Chilkat Pass, British Columbia. Can. Field-Nat. (in press). In presenting t h i s thesis i n p a r t i a l fulfilment of the requirements for an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t f r e e l y available for reference, and study. I further agree that permission for extensive copying of t h i s thesis for scholarly purposes may be granted by the Head of my Department or by his representatives. It i s understood that copying or publication of this thesis for f i n a n c i a l gain s h a l l not be allowed without my written permission. Department of Zoology  The University of B r i t i s h Columbia, Vancouver 8, Canada. Date October 5. 1959  i v TABLE OP CONTENTS Page ABSTRACT i i LIST OP TABLES v i i LIST OP FIGURES i x ACKNOWLEDGMENTS x i i INTRODUCTION . . . . I CLASSIFICATION, TAXONOMIC RELATIONSHIPS AND SUGGESTED HISTORY OP PTARMIGAN 4 C l a s s i f i c a t i o n and Taxonomic Relationships . . . . 4 Order Galliformes 4 Family Tetraonidae, Genus Lagopus 4 Subspecies 5 Hybr i d i z a t i o n 6 Suggested History of Ptarmigan 7 D i f f e r e n t i a t i o n of the Species 7 Development of Subspecies of Lagopus leucurus . 12 PTARMIGAN: THEIR WAYS OP LIFE 22 L i f e Cycle 22 ,N Aggregations . 23 T e r r i t o r i a l Behavior . .,• 28 Sexual Relationships and[ Age at Maturity . . . . 32 Nesting ,- 33 Broods / 38 Pood and Feeding 54 Pood 54 G r i t 58 Water 58 Feeding 60 Predation and Parasitism 60 Molts, Plumages and Other Morphologic Features . . 62 V Page DESCRIPTION OF PLACES IN WHICH PTARMIGAN LIVE 67 Methods 68 Willow Ptarmigan 72 General C h a r a c t e r i s t i c s of the Zone Occupied . . 72 Occupied Areas 76 Unoccupied Areas 90 Rock Ptarmigan 98 General C h a r a c t e r i s t i c s of the Zone Occupied . . 98 Occupied Areas 100 Unoccupied Areas 115 White-tailed Ptarmigan 115 General C h a r a c t e r i s t i c s of the Zone Occupied . . 115 Occupied Areas 116 Unoccupied Areas 125 Summary of the C h a r a c t e r i s t i c s of the Habitat of Ptarmigan 127 Willow Ptarmigan 127 Rock Ptarmigan 128 White-tailed Ptarmigan 128 ECOLOGIC AND GEOGRAPHIC DISTRIBUTION 130 Factors A f f e c t i n g Ecologic D i s t r i b u t i o n 136 Physical Factors 155 Food 157 Escape from Predators 169 Competition 170 Vegetation Structure and Habitat S e l e c t i o n . . . 171 Geographic D i s t r i b u t i o n of Ptarmigan 175 Ecologic Factors 175 Psychologic Factors 180 Geo-historic Events 181 SUMMARY . . . . . . . . . . 189 LITERATURE CITED 195 APPENDIX I. ALLEGED HYBRID: L. MUTUS X L. LAGOPUS . . . . 207 I I . WEIGHTS AND MEASUREMENTS OF PTARMIGAN 210 v i APPENDIX Page I I I . PARASITES OP PTARMIGAN 221 IV. NEST AND BROOD DATA ' 224-V. BANDING DATA. 24-5 v i i LIST OF TABLES Table Page I. H i s t o r i e s of hatching of rock and willow ptarmigan 39 I I . Wet brood-season movements of willow ptarmigan at Chilkat Pass, B r i t i s h Columbia, 1957 42 I I I . Short-term movements of broods of willow ptarmigan at Chilkat Pass, B r i t i s h Columbia, 1957 44 IV. Development of chicks of willow ptarmigan . . . . 51 V. Vegetation i n nesting s i t e s of willow ptarmigan . 82 VI. Frequency and coverage of vegetation categories i n nesting s i t e s of willow ptarmigan 86 VII. Frequency and coverage of vegetation categories i n nesting s i t e s of rock ptarmigan 102 VIII. Vegetation i n nesting s i t e s of rock ptarmigan . . 104 IX. D i s t r i b u t i o n of 30 nests of rock ptarmigan at Eagle Creek, Alaska, with respect to slope . . . 107 X. Foods occurring i n crops of ptarmigan 158 XI. Willow ptarmigan, May 1-3, 1957: Yukon and B r i t i s h Columbia 213 XII. Willow ptarmigan, June-July, 1957-1958: Chilkat Pass, B r i t i s h Columbia 215 XIII. Willow ptarmigan, August-September, 1957-1958 . . 216 XIV. Willow ptarmigan, winter 1956-1957: Saskatche-wan and Alaska 217 XV. White-tailed ptarmigan, May-August, 1957-1958 . . 218 XVI. White-tailed ptarmigan, September, 1957: Mount Arrowsmith (Vancouver Island) and Chilkat Pass, B r i t i s h Columbia 219 XVII. Rock ptarmigan, 1956-1958 220 v i i i Table Page XVIII. White-tailed ptarmigan: incomplete clutches . . . 225 XIX. White-tailed ptarmigan: complete clutches . . . . 226 XX. White-tailed ptarmigan: broods 227 XXI. Willow ptarmigan: incomplete clutches 230 XXII. Willow ptarmigan: complete clutches 231 XXIII. Willow ptarmigan: broods 235 XXIV. Rock ptarmigan: incomplete clutches 239 XXV. Rock ptarmigan: complete clutches 240 XXVI. Rock ptarmigan: broods 242 i x LIST OF FIGURES Figure Page 1. Approximate d i s t r i b u t i o n of f i v e subspecies of Lagopus leucurus . 13 2. Approximate range of three alpine subspecies of Eremophila a l p e s t r i s 17 3. Approximate range of three subspecies of Anthus  s p i n o l e t t a 18 4. Approximate d i s t r i b u t i o n of three species of Leucosticte 20 5. T e r r i t o r i e s of 11 male willow ptarmigan at Chilkat Pass, B r i t i s h Columbia, 1957 31 0 6. Dates of hatching of nests of willow ptarmigan, Chilkat Pass, B r i t i s h Columbia 35 7. Movements of marked broods of willow ptarmigan, C h i l k a t Pass, B r i t i s h Columbia, 1957: W7-57 . . . . 47 8. Movements of marked broods of willow ptarmigan, Chilkat Pass, B r i t i s h Columbia, 1957: W29-57 . . . 48 9. A t y p i c a l nesting s i t e of willow ptarmigan, showing the method used to describe vegetation 69 10. Symbols used i n plant surveys, 1958 73 11. A t y p i c a l p l o t recorded by the survey method used i n 1958 74 12. Diurnal cover number 1 (willow ptarmigan) 78 13. Diurnal cover number 2 (willow ptarmigan) 79 14. Diurnal cover number 3 (willow ptarmigan) 80 15. Diurnal cover number 4 (willow ptarmigan) 81 16. Average composition of vegetation i n nesting s i t e s of willow ptarmigan 87 17. Nesting s i t e of a willow ptarmigan near A t l i n , B r i t i s h Columbia (June 15, 1958) 88 X Figure Page 18. a. River terrace topography used by willow ptarmigan, Chilkat Pass, B r i t i s h Columbia . . . . 91 b. Excellent brood cover f o r willow ptarmigan near a creek, Chilkat Pass, B r i t i s h Columbia . . 91 19. a. Marginal brood cover i n dry b i r c h s i t e s , A t l i n and Chilkat Pass, B r i t i s h Columbia . . . . 92 b. Wet tundra with r e s t r i c t e d use by broods of willow ptarmigan, Chilkat Pass, B r i t i s h Columbia 92 20. Herbmat at Chilkat Pass, B r i t i s h Columbia (July, 1957) 94 21. Seasonal changes i n aspect of alpine herbmats . . 95 22. "Savannah" community and i t s r e l a t i o n to other vegetation types, Chilkat Pass, B r i t i s h Columbia 97 23. S o l i f l u c t i o n ridge nesting s i t e of rock ptarmigan, Eagle Creek, Alaska 106 24. S t r u c t u r a l diagram of a t y p i c a l brood cover of rock ptarmigan 109 25. Brood cover of rock ptarmigan near A t l i n , B r i t i s h Columbia (July 9, 1958) 110 26. Paired vegetation diagrams of u t i l i z e d and nearby u n u t i l i z e d areas i n zone inhabited by rock ptarmigan broods I l l 27. Rock s l i d e u t i l i z e d by w h i t e - t a i l e d ptarmigan near Boulder Creek, A t l i n , B r i t i s h Columbia (August 24, 1957) 119 28. Ledge and r o c k s l i d e habitat of wh i t e - t a i l e d ptarmigan 122 29. P e l l - f i e l d u t i l i z e d by wh i t e - t a i l e d ptarmigan, Mile 97 Haines Road, B r i t i s h Columbia (July 3, 1958) 124 30. Luetkea - Phyllodoce - Cassiope community near Palmer, Alaska (July 9, 1958) 126 31. Approximate range of white-tailed ptarmigan . . . 131 32. Approximate range of willow ptarmigan i n North America 132 x i Figure Page 33. Approximate range of rock ptarmigan i n North America 133 34. Overlap of the geographic ranges of three ptarmigan 134 35- Mile 75 Haines Road, Chilkat Pass, B r i t i s h Columbia 138 36. Area 1 mile east of mile 65 Haines Road, Chilkat Pass, B r i t i s h Columbia 139 37. Interspersion of rock and whi t e - t a i l e d ptarmigan breeding habitat, Chilkat Pass, B r i t i s h Columbia 140 38. Coastal side of Coast Range, northern B r i t i s h Columbia 142 39. L i t t l e Susitna River area, Talkeetna Mountains, Alaska 143 40. Boulder Creek, A t l i n , B r i t i s h Columbia 145 41. Nine^mile Mountain, Hazelton, c e n t r a l B r i t i s h Columbia 146 42. Grant Creek area, near Lorna Lake, east slope of Coast Range, southcentral B r i t i s h Columbia i . 147 43. Topographic and a l t i t u d i n a l changes i n vegetation and ptarmigan d i s t r i b u t i o n at Eagle Creek, Alaska 149 44. Proximity of nesting s i t e s of rock and willow ptarmigan, Eagle Creek, Alaska 150 45. Mile 12, Denali Highway, near Paxson, c e n t r a l Alaska 151 46. Mount Arrowsmith, Vancouver Island, B r i t i s h Columbia 153 47. Sunwapta Pass, Banff National Park, and Columbia I c e f i e l d s , Jasper National Park, Alberta . . . . 154 48. Topographic diagram of the d i s t r i b u t i o n of ptarmigan i n western North America 182 x i i ACKNOWLEDGMENTS This report i s "based p r i m a r i l y on f i e l d work supported wholly by grants from The A r c t i c I n s t i t u t e of North America. The National Research Council of Canada financed a large part of the academic and l i v i n g expenses of the author i n 1957 and 1958. To those two organizations, without whose support the research could not have been c a r r i e d out, I extend my sincere thanks. Many people contributed generously of t h e i r time and thought to the project. Dr. Ian McT. Cowan, Dr. James P. Bendell and Dr. Miklos M. D. P. Udvardy, a l l of the Department of Zoology, U n i v e r s i t y of B r i t i s h Columbia, and Mr. James W. Brooks, Senior B i o l o g i s t , Alaska Department of Pish and Game provided many h e l p f u l suggestions throughout the study. Dr. John Buckley, former Leader of the Alaska Cooperative Wild-l i f e Research Unit, Dr. William A. P u l l e r and Mr. Donald R. Plook, B i o l o g i s t s , Canadian W i l d l i f e Service, Mr. Ernie Kuyt, E c o l o g i s t , Saskatchewan Department of Natural Resources, and Mr. Wilbur P. Libby, Alaska Department of Pish and Game helped gr e a t l y i n several phases of the f i e l d research. Special thanks are due to Mr. Harold J . Gibbard, B i o l o g i s t , Ontario Department of Lands and Forests, f o r h i s welcomed companionship and v a l u -able assistance during the summer of 1957; to Miss J u d i t h Stenger, Department of Zoology, U n i v e r s i t y of B r i t i s h Columbia, who completed the ptarmigan food habits analyses and gave x i i i thoughtful advice on many of the ideas incorporated i n t o t h i s report; and to Dr. Helmut K. Buechner, Department of Zoology, State College of Washington, f o r h i s valuable c r i t i c i s m of the f i n a l manuscript. The drawings were prepared by Mr. Steve A l l u r e d , Photography Department, State College of Washington, and Mrs. A l f r e d B. Butler of Pullman, Washington, typed the f i n a l d r a f t of the t h e s i s . I am indebted to both f o r t h e i r help i n the preparation of the present report. F i n a l l y , I extend my warm thanks to the many fel l o w graduate students and i n s t r u c t o r s of the U n i v e r s i t y of B r i t i s h Columbia and the State College of Washington, whose countless f r i e n d l y c r i t i c i s m s and spontaneous ideas have become an i n t e g r a l part of t h i s t h e s i s . 1 INTRODUCTION Studies of the d i s t r i b u t i o n of animals u s u a l l y are con-cerned with one of two phenomena: the patterns formed by the ranges of several species (or l a r g e r taxa) or the fac t o r s which create the d i s t r i b u t i o n a l pattern of one species. The former type of i n v e s t i g a t i o n , i n which groups of animals are studied, i s termed zoogeography. Zoogeography, paleontology and geology often are used i n combination to describe the o r i g i n and spread of species. The emphasis i s on broad patterns, and the approach i s geographic. In contrast, the second method i s e s s e n t i a l l y ecologic. Animals have f i n i t e ranges, and the basic aim of ecologic zoogeography i s to determine the f a c t o r s which l i m i t the d i s -t r i b u t i o n of a species. Ecologic zoogeography, therefore, i s p r i m a r i l y the study of boundaries—those which e x i s t at the l o c a l l e v e l between populations as well as those which d e l i n -eate the range of the species as a whole. A second problem of ecologic zoogeography concerns the d i s t r i b u t i o n of c l o s e l y r e l a t e d forms. I t seems to be gener-a l l y true that the more s i m i l a r are the requirements of two animals, the le s s l i k e l y they are to be found i n the same place, p a r t i c u l a r l y during the breeding season. In the class Aves, two general s i t u a t i o n s apply to re l a t e d forms: the two species may occur i n separate geographic areas, or, i f t h e i r d i s t r i b u t i o n s overlap, they w i l l be found i n d i f f e r e n t niches 2 i n the same l o c a l i t y . Each of these s i t u a t i o n s has been studied from several d i f f e r e n t standpoints, e s p e c i a l l y as to the importance of physiology, food, i n t e r s p e c i f i c competition and psychologic f a c t o r s . Recent or "basic studies of these factors are found i n papers by Dawson (1954; physiology), Lack (1933, 194-0, 1944, 1947; psychologic f a c t o r s , food and competition), P i t e l k a (1951; i n t e r s p e c i f i c s t r i f e ) , S a l t (1952; physiology), Svardson (1949; competition), Wallgren (1954; physiology) and others. The study reported herein i s an attempt to determine the influence of various f a c t o r s on the d i s t r i b u t i o n of mem-bers of the avian genus Lagopus i n western North America. The three members of t h i s genus (Lagopus lagopus, L. leucurus and L. mutus) are very s i m i l a r i n outward appearance and i n general requirements. Each has a d i s t i n c t pattern of geographic d i s -t r i b u t i o n s but there are broad areas where two or a l l three species are found breeding i n adjacent, a l t i t u d i n a l l y separated zones. The discussion centers around (1) the fa c t o r s which maintain the d i s t i n c t i v e d i s t r i b u t i o n of populations of the various species when they breed i n the same l o c a l i t y , and (2) fa c t o r s that influence the geographic range of each spe-c i e s . Vegetation form and m i c r o t e r r a i n and t h e i r r e l a t i o n s h i p to habitat s e l e c t i o n are emphasized. A knowledge of the basic requirements of ptarmigan i s e s s e n t i a l to the s o l u t i o n to the problems outlined above. Present information on that subject i s fragmentary, and the conclusions of the study are n e c e s s a r i l y t e n t a t i v e . To f i l l i n 3 as many gaps as possible i n the l i f e h i s t o r y of ptarmigan, the author spent a part of three summers gathering information on the habits of these birds i n portions of B r i t i s h Columbia, Yukon and Alaska. Data on vegetation and topography i n places where ptarmigan l i v e were obtained through quantitative vege-t a t i o n surveys and observations i n a number of d i f f e r e n t areas representing a wide range of conditions. The text contains four main sections. In the f i r s t s e c t i o n the r e l a t i o n of ptarmigan to other birds i s outlined and problems connected with s p e c i a t i o n and h y b r i d i z a t i o n are discussed. The second s e c t i o n presents a summary of contem-porary knowledge of the ways i n which ptarmigan l i v e ; the t h i r d section describes some of the places i n which each species breeds. Together those three sections provide a basis f o r the discussion of d i s t r i b u t i o n presented i n the f i n a l por-t i o n . 4-CLASSIFICATION, TAXONOMIC RELATIONSHIPS AND  SUGGESTED HISTORY OF PTARMIGAN Classification and Taxonomic Relationships Order Galliformes The order Galliformes i s composed of ground-dwelling birds possessing short, decurved b i l l s ; s t i f f , rounded wings; scutellate or feathered t a r s i ; and feathers with aftershafts. In North America the Order includes ehachalaeas (Cracidae), pheasants and quail (Phasianidae), grouse and ptarmigan (Tetraonidae) and turkeys (Meleagrididae). In a recent c l a s s i f i c a t i o n (Mayr and Amadon, 1951) the last three groups were reduced to subfamilies and placed i n the family Phasianidae. An analysis of egg-white proteins by Sibley (1959) also suggests strongly that turkeys are closely related to pheasants and should not be ranked as a separate family. However, I have followed the American Ornithologist's Union Check-list of North American Birds (1957) i n this instance and throughout the report. The f i r s t f o s s i l s of galliforms were found i n deposits of the middle Eocene Epoch i n North America (Howard, 1950). Family Tetraonidae, Genus Lagopus Members of the family Tetraonidae are gallinaceous birds of north-temperate and arctic regions, characterized by feath-ered t a r s i . Ptarmigan (Lagopus) d i f f e r from grouse i n their 5: arctic-alpine distribution, possession of feathered toes and white plumage i n winter. Three distinct species comprise the genus: L. mutus (Montin\ the rock ptarmigan (circumpolar); L. lagopus (Linnaeus], the willow ptarmigan (North America and Eurasia); L. leucurus (Richardson^ the white-tailed ptarmigan (North America). The red grouse of Great Brita i n i s a border-line form sometimes recognized as a species (L. scoticus), sometimes as a subspecies of willow ptarmigan (L. 1 . scoticus), with which i t interbreeds when the two are introduced into the same area (Watson, 1 9 5 6 ) . Subspecies The problem of subspecies i s a d i f f i c u l t one i n the genus Lagopus. Seven races of lagopus, thirteen of mutus, and five of leucurus are recognized i n North America by the Ameri-can Ornithologist's Union. The total number of races and the names of many forms have changed markedly over the past few decades, and further revisions probably w i l l be made. In Greenland (Salomonsen, 1 9 5 0 a ) and Eurasia (Dementiev et a l . , 1952) the taxonomic situation i s no more settled than i n North America. Geographic variation (resulting from isolation, d i f -ferences i n selective forces and genetic variation) i s one reason for the indecision regarding the taxonomy of ptarmigan. However, this is not the only problem with which taxonomists have to contend. The situation i s also confused by the sear-city of specimens, the disagreement among workers as to the evaluation of morphologic variation, the d i f f i c u l t y i n 6 describing colors i n terms that are universally meaningful and the unfortunate fact (for taxonomists) that ptarmigan usually are losing feathers of one hue and gaining those of another. In fact, a single adult specimen i n August may possess feathers whichooriglnated from molts i n the previous f a l l , spring, summer and i n the current early f a l l season. Geographic clines i n summer plumage coloration, occurrence of dark feathers i n winter and certain meristic characters may be exhibited by one species of ptarmigan (Watson, 1956). These morphologic gradients may be corre-lated with gradients i n physiologic characteristics which are unidentified as yet. Therefore, questions confronting tax-onomists may bear a close relationship to ecology, since habitat selection may vary due to physiologic differences within one species. Nevertheless, the description of geo-graphic variation i n ptarmigan i s so chaotic, and the meaning of existing differences so uncertain, that there seems to be no alternative but to consider each species as an entity with respect to i t s relationships to vegetation, topography and other environmental features. Hybridization Relatively e f f i c i e n t mechanisms seem to exist which prevent interbreeding among ptarmigan where the species l i v e elose together. Of course, the morphologic similarity of ptarmigan (particularly mutus and lagopus) and the r e l a t i v e l y small number of specimens seen by experienced persons compli-cate the detection of hybrids. After examining many specimens % and searching through pertinent l i t e r a t u r e of Eurasia and North America, Watson (1956) found no eases of h y b r i d i z a t i o n among ptarmigan. Two cases of alleged h y b r i d i z a t i o n have come to my attention: C o l l e t t (1906) reported a lagopus X mutus hybrid from Norway, and Harper (1953) c o l l e c t e d a presumed lagopus X mutus cross from N u e l t i n Lake, Northwest T e r r i -t o r i e s , Canada. On the basis of c h a r a c t e r i s t i c s given f o r the l a t t e r b i r d , i t i s my opinion that the specimen i s a rock ptarmigan (see Appendix I ) . Strangely, genuine hybrids are known between rock ptarmigan and black game (Lyrurus t e t r i x ) , red grouse and black game ( C o l l e t t , 1898) and willow ptarmigan and spruce grouse (Canachites canadensis) (Taverner, 1932). I t i s d i f f i -c u l t to explain such in t e r g e n e r i c crosses, e s p e c i a l l y i n view of the r a r i t y of intrageneric h y b r i d i z a t i o n . Perhaps i n t e r -genetic hybrids are merely easier to i d e n t i f y . Suggested History of Ptarmigan' D i f f e r e n t i a t i o n of the Species Using a l l of the a v a i l a b l e evidence from the f o s s i l record, morphology, behavior and zoogeography, Johansen (1956) attempted to show how ptarmigan may have ari s e n . Those ideas which p e r t a i n mostly to forms found i n North America were translated from the o r i g i n a l German, and are summarized here: (1) F o s s i l s of ptarmigan are known only from the Pleistocene Epoch, when lagopus and mutus were already well d i f f e r e n t i a t e d . (2) The present ranges of ptarmigan a l l were g l a c i a t e d at some time during the Pleistocene except parts of northern Alaska and a large area i n northeastern S i b e r i a . I t seems l i k e l y that the genus arose i n the la t e Pliocene Epoch i n northeast Asia, spreading west to Europe and east to North America during Pleistocene i n t e r g l a c i a l s . (3) Very e a r l y i n the Pleistocene mutus spread into North America, wandering f a r southward to Colorado and New Mexico, where a population became i s o l a t e d . Prom t h i s population arose a new species, leucurus, which i n sub-sequent times reached toward the north, forming several subspecies i n the process. (4) A population of lagopus was i s o l a t e d s i m i l a r l y i n Great B r i t a i n , and gave r i s e to the form L. 1_. s c o t i -cus during a r e l a t i v e l y warm period. (5) Prom various r e f u g i a (some of which are not well established) e a r l y pioneers of mutus spread eastward across North America into Greenland and Iceland, under-going d i f f e r e n t i a t i o n i n l a t e r periods of i s o l a t i o n . (6) The form L. 1. leucopterus may have remained i n r e f u g i a i n the western Canadian A r c t i c A r c h i p e l a g o — a refugium also i ndicated by the d i s t r i b u t i o n of gyrfalcons and caribou. (7) Quite l a t e i n the Pleistocene, both mutus and lagopus invaded Alaska from Asia, meeting e a r l i e r a r r i v a l s i n some places and f i n d i n g unoccupied areas i n others (such as the Ale u t i a n I s l a n d s ) . New subspecies have 9. arisen from Asian forms i n these formerly unoccupied places. It i s apparent (see 3 above) that Johansen believes that white-tailed ptarmigan arose from rock ptarmigan. Some evidence i n favor of that conclusion, but not mentioned by Johansen, i s given here: (1) As w i l l be shown later, the breeding habitat of leucurus i s most similar to that of mutus i n topo-graphic and vegetational aspect. (2) White-tailed ptarmigan are definitely grayish i n summer plumage. Rock ptarmigan tend to be yellowish or grayish brown i n summer, whereas willow ptarmigan are definitely a rich, reddish brown. (3) Certain variations i n t a i l color suggest a more simi-l a r genetic make-up i n that respect between mutus and leucurus than between lagopus and leucurus. The t a i l of leucurus i s white at a l l times of the year. How-ever, I have seen two specimens with wholly or pa r t i a l l y black rectrices. One was collected i n the Rocky Mountains of B r i t i s h Columbia, the other i n Washington. The former i s i n the museum of the Univer-si t y of B r i t i s h Columbia, the other at Washington State University (Pullman). Swarth (1924) found that i n some populations of mutus i n central B r i t i s h Columbia, birds occur with large amounts of white i n the t a i l . In this connection, Johnsen (1942) remarks that "Perhaps this species [leucurus] should be taken as the last link i n 10 the L. mutus chain with i t s variations i n the colour of the t a i l feathers." (4) Swarth (1924) mentions that the "bill of mutus tends to be smaller (more li k e the b i l l of leucurus) i n the southern part of i t s range i n western Worth America. (5) The willow ptarmigan i s the largest of the three species i n total length and weight, and the white-tailed ptarmigan i s the smallest. (6) Willow ptarmigan males usually remain with the female and the chicks at least u n t i l f a l l ; rock and white-tailed ptarmigan cocks do not remain with the brood after i t hatches. An interesting concept i n Johansen's paper concerns the reaction of populations of ptarmigan to changes which accompany glaciation. In the north, ptarmigan spread during interglaeials, becoming restricted to refugia or "pushed back" to the southern edge of the ice when g l a c i a l advance was at i t s height. In the mountains of the southern part of Russia and the United States, however, and i n Japan, Switzerland and Spain, interglaeials were times of progressive isolation as the tundra retreated higher and higher up the mountains. If tundra areas expanded i n such mountainous areas during periods of g l a c i a l advance, then ptarmigan populations probably could disperse more freely under those conditions. Therefore, i n terms of genetic make-up, g l a c i a l advance would promote d i f -ferentiation i n the Arctic and intermingling i n southern areas; gla c i a l retreat would have the opposite effect. 11 A t h i r d point made "by Johansen (1956) should "be com-mented upon b r i e f l y . He assumed that i n c i p i e n t leucurus popu-l a t i o n s became i s o l a t e d early i n the Pleistocene. The question i s whether t h i s would give the o r i g i n a l mutus forms time; to change into a species as well defined as leucurus i s today. Estimates of the rate of avian s p e c i a t i o n have been made i n very few p u b l i c a t i o n s , and inferences from one species prob-ably should not be transferred u n c r i t i c a l l y to others. Never-theless, some previous guesses are mentioned here to show the general range i n time necessary f o r subspecies formation i n b i r d s . Mayr (1942) f e l t that the usual time required f o r d i f f e r e n t i a t i o n of H o l a r c t i c avian subspecies was 5»000 to 15,000 years, but Haldane (1954) believed that "no measurable evolutionary changes are to be expected i n most species i n 10,000 years." Moreau (1930) showed that one subspecies of the crested l a r k of A f r i c a (Q-alerida c r i s t a t a nigricans) probably evolved from another form i n the l a s t 10,000 years, while G. £. brachyura and a wren-warbler may have done so i n the l a s t 5,000 years. That length of time, i n Moreau's opinion, may be a minimum f o r b i r d s . Watson (1956) believed that Lagopus lagopus scoticus probably did not d i f f e r e n t i a t e u n t i l beginning about 6,000 B.C. I f that i s meant to i n d i -cate the t o t a l time from the beginning of i s o l a t i o n , s p e c i -atio n processes proceeded very r a p i d l y i n that form, as i t i s now nearly a f u l l species. Prom the above estimates of the rate of species formation i n b i r d s , therefore, i t appears that an early Pleistocene o r i g i n f o r L. leucurus (as proposed by Is2 Johansen) would allow s u f f i c i e n t time f o r the development of white-tailed ptarmigan and t h e i r several subspecies. (The Pleistocene Epoch i s considered to have begun about one m i l l i o n years ago.) Development of Subspecies of I^ a^ opus leucurus The possible h i s t o r y of subspecific development of white-tailed ptarmigan has received no at t e n t i o n up to t h i s time. The r e l a t i o n s h i p s among races of leucurus are examined here. The tentative nature of these suggestions should be emphasized, e s p e c i a l l y since the v a l i d i t y of the races i s not f u l l y established. The approximate range occupied by each c u r r e n t l y recognized subspecies of leucurus i s shown i n Figure 1. Broadly speaking, white-tailed ptarmigan i n h a b i t an elongate range i n alpine areas from extreme northern New Mexico to cent r a l Alaska, a north-south distance of about 3,000 miles. The general range of each subspecies i s as follows (from the American Orn i t h o l o g i s t ' s Union Check-list of North American Birds, 1957): pen i n s u l a r i s: Southcentral Alaska (Mount McKinley) to the Kenai Peninsula, extending east and southeast to G l a c i e r Bay and White Pass. leucurus: Central Yukon (Og i l v i e Mountains), western MacKenzie, B r i t i s h Columbia and west-c e n t r a l A l b e r t a south to the northern border of the United States. s a x a t i l i s : Vancouver Island, B r i t i s h Columbia. Figure I. Approximate distribution of five subspecies of Lagopus leucurus 14 rainierensis: In Washington from Mount Baker south to Mount Adams and Mount St. Helens, and Calispell Peak. Intergrades along the northern boundary of the United States with the race leucurus. altipetens; Alpine summits i n the Rocky Mountains from Lewis and Olark and Teton counties, Montana, south through Wyoming and Colorado to New Mexico (C o s t i l l a Peaks, formerly to Taos and Truchas Peaks). If i t i s accepted that leucurus originated from a stock of mutus isolated i n the southern Rocky Mountains, then i t i s reasonable to assume that the original dispersal of leucurus, after differentiation, was northward. Populations remaining i n the Rocky Mountains probably expanded and contracted their ranges during alternate warming and cooling, and now occupy essentially two separate ranges (Wyoming and Colorado). Other areas such as the Uintah Mountains i n Utah have been occupied by the form altipetens up to recent times (Behle, 1944-). The range of this subspecies probably was never continuous over broad areas, but always s p l i t by the nature of the topography and vegetation into populations occupying isolated mountain systems. After the f i r s t great northward expansion of the newly formed leucurus, extensive glaciation isolated various remnants in different areas. The northern form peninsularis may have survived on nunataks i n the mountains of southcentral Alaska, 15: which are thought to have been refugia for certain a r c t i c -alpine plants i n the Pleistocene (Hulten, 1937). Another refugium proposed by Hulten and accepted by many other botanists (Porsild, 1951) was the upper Yukon Valley, separated from the one just mentioned by ice sheets. The race leucurus may have survived there—but i f that is so, i t i s d i f f i c u l t to explain why mountains north of the Yukon River (including the Mackenzie Mountains) have not been occupied more extensively. One other p o s s i b i l i t y i s that leucurus (the race) found refuge i n the highlands of southcentral B r i t i s h Columbia, and have not invaded a l l suitable areas because of the short time that has elapsed since the glaeiation ended. During the Wisconsin glaeiation populations may have been isolated i n the Olympic Mountains (see Jones, 1936, for evidence that alpine plants survived glaeiation there) and the Cascade Mountains of Washington and Oregon. Probably there has been l i t t l e exchange between Vancouver Island white-tailed ptarmigan (saxatilis) and mainland forms (leucurus). The race rainierensis i s not isolated completely, and interbreeds with leucurus i n the region of the B r i t i s h Columbia-United States border. Two factors which may tend to maintain the d i s t i n c t -ness of those two races are the discontinuous nature of suitable habitats and the non-migratory habits of white-tailed ptarmigan. Three other alpine birds associated with white-tailed ptarmigan i n summer are the alpine races of horned larks (Eremophila alpestris), the water pipit (Anthus spinoletta) and rosy finches (Leucosticte austrails, L. atrata and I. tephrocotis). These birds may have been subjected to the same 16 changes i n environment during the Pleistocene as leucurus, and t h e i r d i s t r i b u t i o n s are discussed "briefly here f o r that reason. The present ranges of those birds emphasize the r o l e of g l a e i a t i o n i n the d i f f e r e n t i a t i o n of subspecies. Por ex-ample, of the three alpine races of horned larks (Pig. 2 ) i n i n North America, two have r e s t r i c t e d ranges i n the S i e r r a Nevada Mountains of C a l i f o r n i a (sierrae) and i n the Cascade and Olympic Mountains of Washington ( a l p i n a ) . The t h i r d race ( a r c t i c o l a ) may have spread from r e f u g i a i n the Nome, Alaska, area ( P o r s i l d , 1939» gives botanic evidence of that refugium), i n the Yukon V a l l e y or i n i n t e r i o r B r i t i s h Columbia. Inex-p l i c a b l y , horned l a r k s apparently have not occupied alpine areas i n the c e n t r a l and southern Rocky Mountains. The water p i p i t (Pig. 3) i s a widespread form whose North American races generally occupy broad regions. However, one subspecies ( a l t i c o l a ) has become d i f f e r e n t i a t e d i n the Colorado Rocky Mountains, i n d i c a t i n g prolonged i s o l a t i o n there. The eastern subspecies rubescens and the western p a c i f i c u s meet i n the upper Yukon V a l l e y region. This pattern of d i s t r i b u t i o n suggests separate Pleistocene i s o l a t i o n i n two areas: western a r c t i c or subarctic North America, and c e n t r a l or eastern Canadian A r c t i c . In the genus Leucosticte, the pattern of southern i s o -l a t e d forms e x i s t s , but two separate species are recognized. Perhaps i n t h i s genus the i s o l a t i o n has been more complete or of longer duration, or else speeiation occurred more r a p i d l y i n the rosy finches than i n the other birds discussed. The two 17 Figure 2. Approaimote range of three alpine subspecies of Eremophilo olpegtris Figure 3. Approximate range of three subspecies of Anthus spinoletto 19 southern species are australis and L. atrata (for d i s t r i -butions see Fig. 4 ) ; neither form has developed subspecies. L. tephrocotis, on the other hand, occupies a large area to the west and north of the southern Rocky Mountain species, and has s p l i t into many races. It i s interesting that the race tephrocotis parallels l i t t o r a l i s for nearly 2 , 0 0 0 miles, but the two forms s t i l l remain morphologically distinguishable. Tephrocotis occupies the Canadian Rocky Mountains and the MacKenzie Mountains; l i t t o r a l i s inhabits discontinuous ranges i n the Cascade Mountains and more or less connected ranges along the coast and i n southeentral Alaska. Subspecies occupying restricted areas have developed i n extreme western Alaska and i n California; griseonucha lives i n the Aleutian Islands and Alaska Peninsula, umbrina is restricted to the P r i b i l o f f Islands and St. Matthew Island i n the Bering Sea and dawsoni lives i n the Sierra Nevada Mountains of California. The evidence obtained i n this brief review of the dis-tributions of white-tailed ptarmigan, rosy finches, water pipits and alpine horned larks suggests that these alpine-arctic birds may have had a paral l e l history i n Pleistocene times. It i s to be expected that differences do exist, as each species has i t s own genetic constitution. However, i t appears that broad changes in climate or other conditions for l i f e i n the western Cordillera have affected those birds similarly during the Pleistocene and Recent Epochs. A l l four taxa con-tain populations which were isolated in the Rocky Mountains of the United States, and which differentiated there to the r a c i a l 20 Figure 4 . Approximate distribution of thre« species of Lcucostictf 21 or s p e c i f i c l e v e l . The water p i p i t i s the only species which does not also include morphologically d i f f e r e n t i a t e d popula-tions i n the Coast and Cascade Mountains of southern B r i t i s h Columbia and the United States. Each of the four birds has a race which occupies the ent i r e Coast Range i n B r i t i s h Columbia and extensions of that range into Alaska. In two species (white-tailed ptarmigan and water p i p i t s ) the same race also occupies the Rocky Mountains of B r i t i s h Columbia and Alberta. In Lagopus leucurus and Leucosticte tephrocotis there i s also an i n d i c a t i o n of processes of d i f f e r e n t i a t i o n i n southcentral and western Alaska. 22 PTARMIGAN; THEIR WAYS OF LIFE The purpose of this section i s to show the nature of the place of ptarmigan i n tundra communities. It i s hoped that this introduction to the l i f e of ptarmigan w i l l provide a "basis for an evaluation of the. main theme of the present study, the roles of vegetation, geography and time i n determining the distribution of Lagopus i n North America. Life Cycle There are only two major publications dealing with the l i f e history of ptarmigan. One i s a two-volume work (Anon., 1911) on L. 1. scoticus, the other an unpublished doctoral thesis (Watson, 1956, University of Aberdeen). The lat t e r i s especially valuable, as i t provides an up-to-date compilation of knowledge on mutus (with a considerable amount of data on lagopus as well), interpreted by one who spent several years i n Scotland, Scandinavia and North America doing original research. In North America there have been only four intensive studies of ptarmigan: two projects on rock and willow ptarmigan by students at the University of Alaska, a study of lagopus at Churchill, Manitoba (Cecil Law, pers. comm.) and a long-term study of willow ptarmigan i n Newfoundland begun i n 1955. None of these have been published i n their entirety. In my own research, l i f e history studies were secondary to work on dis-tributional ecology; however, some new information on the lives 23 of ptarmigan was obtained, and i s incorporated into this sec-tion. The white-tailed ptarmigan i s probably the least-studied galliform i n Worth America, as w i l l become apparent i n the following discussion. A research project has been i n i t i a t e d on this species i n Montana. Aggregations A study of seasonal changes i n the functional grouping of ptarmigan i s of interest from the standpoints of dispersal, mating and related subjects. Migration and dispersal are im-portant i n maintaining a circulation of genetic material, and flocking behavior may affect the establishment and duration of the pair bond. At most times of the year ptarmigan demonstrate a greater willingness (and perhaps, ability) to f l y than any other galliform i n North America. It i s quite possible that this mobility allows ptarmigan to l i v e i n areas which otherwise would be uninhabitable due to lack of food and shelter i n win-ter. Many populations of ptarmigan are migratory i n spring and early f a l l , and nomadic i n winter. In most cases the movements seem to be directly related to food supplies. However, certain high-arctic rock and willow ptarmigan carry out annual migra-tions which seem to have gone beyond an immediate cause and effect relationship to food, to become established as habitual a c t i v i t i e s of those populations. Some instances of both types of movement patterns are l i s t e d here: 24-(1) Pood-directed movements: a) Arctic Slope, northern Alaska (Bailey, 194-8). L. lagopus: "as "birds eliminate the [willow] leaves in one section they move on to more favorable loca-tions." b) Hooper Bay, western Alaska (Brandt, 194-3). L. lagopus: Ptarmigan migrate inland to timbered watercourses and associated willows for food i n the winter. c) East Greenland (Gelting, 1937). L. mutus: Rock ptarmigan move from low to high altitudes i n the interior i n the f a l l as certain preferred foods become available; interior to coast movements i n winter connected with the a v a i l a b i l i t y of Salix on the coast. (2) Habitual migrations: a) Windy River, Northwest Territories (Mowat and Lawrie, 1955). L. lagopus: As many as 2,GOO seen daily from May 31 to June 2, 194-7, during the annual northward migration. Many also seen i n the f a l l from October 10 to November 1 moving southward. b) Northeast Greenland (Manniche, 1912). L. mutus: Birds leave i n October, returning i n February even when the sun i s not yet v i s i b l e . c) Cape Chidley, northern Labrador (Gross, 1937). L. mutus: Immense flocks moving south from October 1-15, presumably from Baffin Island; birds return north i n May and June. 25 Other examples eould "be given, "but the main point seems cle a r : ptarmigan often carry out long movements during the period September - June which are u l t i m a t e l y or immediately directed toward obtaining food. The distance moved often de-pends on l o c a l conditions, and may vary from year to year. I t i s probable that some populations, e s p e c i a l l y i n subarctic areas, do not move out of the breeding l o c a l i t y i f winter food supplies are s u f f i c i e n t . In terms of gene flow, therefore, one would expect non-migratory groups to be more prone to morpho-l o g i c divergence than nomadic or migratory groups. This i s borne out i n extreme s i t u a t i o n s such as on the A l e u t i a n Islands, where seven races of mutus ( a l l permanent residents on c e r t a i n i s l a n d s or i s l a n d groups) have been described. By contrast, rock ptarmigan i n a r c t i c Canada are r e l a t i v e l y u n d i f f e r e n t i -ated; these populations carry out long movements as just described i n M n t e r , f a l l and spring. As leucurus i s t y p i c a l l y non-migratory, one would expect t h i s species to be s p l i t i n t o several subspecies. Morphologically d i s t i n c t races have de-veloped on Vancouver Island and i n the Mount Rainier, Washington, area. There are, however, only two races occupying the vast s t r e t c h of country from southern B r i t i s h Columbia to Alaska. Perhaps these populations have occupied t h e i r present ranges for such a short time that d i f f e r e n t i a t i o n has not occurred. Aggregations break up and pairs are formed with the onset of the breeding season. The p a i r bond i n ptarmigan u s u a l l y l a s t s only from mating i n the spring to the separation of the adults i n summer ( i n mutus and leucurus) or to the 26 commencement of f a l l f l o c k i n g i n most willow ptarmigan. There have been a few statements made that mutus and lagopus stay together i n family groups throughout the f a l l and winter (Peters and Burleigh, 1951; Sutton, 1932). There seems to be no evidence f o r t h i s except that old and young birds often are found i n the same f l o c k s . The large si z e of migratory f l o c k s , the evident s p l i t t i n g of large groups i n winter, the occurrence of f l o c k s i n which one sex predominates ( G r i n n e l l , 1900; Bailey, 1948; Salomonsen, 1950 ; Harper, 1953) and the s h u f f l i n g and s p l i t t i n g of broods which may occur i n l a t e summer (shown by data from the present study) a l l suggest that p a i r bonds are broken a f t e r one season. However, i n non-migratory populations there i s a greater l i k e l i h o o d that pairs would remain together f o r more than one season. Por example, a p a i r of lagopus banded as adults i n 1957 i n Ghilkat Pass was recaptured with a brood i n the same area i n 1958 (Appendix V). This may i n d i -cate a l a s t i n g p a i r bond, or perhaps merely the f i d e l i t y of both male and female to one area. Willow ptarmigan l i v e i n family groups a l l summer i n most regions, but males of the other species leave the hen im-mediately a f t e r the chicks hatch. The adults of mutus and leucurus u s u a l l y do not come together again u n t i l l a t e summer or early f a l l when f l o c k s are formed. A few reports of summer flo c k s of male willow ptarmigan (Dixon, 1927; Baldwin and Reed, 1954; I r v i n g and Paneak, 1954; Watson, 1957; Kessel et a l • , 1958) and male rock ptarmigan ( P i t z g e r a l d , 1946) have been pub-l i s h e d . The age composition and s i g n i f i c a n c e of those f l o c k s are unknown. Peter Shepherd (personal communication) stated that lagopus males at Selawik, on the coast of the Bering Sea, Alaska, did not remain with the brood after the chicks hatched, but were found i n small flocks i n June and July. It would be interesting to investigate this situation further to discover whether there i s a relationship between the occurrence of sum-mer flocks of males and desertion of the female by lagopus cocks. The formation of f a l l flocks occurs at different times i n different areas, but begins most frequently i n the period August 1 to October 15. Flocks containing more than one species of ptarmigan have been reported occasionally. Bailey (1927) saw winter flocks containing leucurus and mutus i n southern Alaska, and i n my own studies groups of the same two species were observed i n early spring at Ohilkat Pass, B r i t i s h Colum-bia. Rock ptarmigan and willow ptarmigan are seen frequently in the same flocks i n f a l l and winter (DeLeonardis, 1952; Mowat and Lawrie, 1955; Osgood, 1904). At Chilkat Pass and near Palmer, Alaska, loose flocks of lagopus and leucurus were seen i n the present investigations. From this discussion i t can be seen that the size and nature of functional groups of ptarmigan vary according to the operation of internal factors (gregariousness, tendency toward t e r r i t o r i a l i t y and strength of male-female and adult-young re-lationships) as well as certain environmental conditions. Gregariousness seems strongest i n the f a l l , when flocks are formed even before apparent food shortages occur. Declining 28 t e r r i t o r i a l behavior i n adults and the increased independence of the young may contribute to the autumnal f l o c k i n g phenomenon. In winter, gregariousness and s p a t i a l r e s t r i c t i o n of food sup-p l i e s tend to maintain f l o c k s . As food becomes more accessible i n spring, and as reproduction-directed behavior i s strength-ened, winter f l o c k s d i s i n t e g r a t e . P a i r bonds probably l a s t only one breeding season, except where p a r t i c u l a r l y sedentary popu-l a t i o n s e x i s t . T e r r i t o r i a l Behavior Ptarmigan are among the species of birds showing " t e r r i t o r i a l " behavior; i . e . , they defend a c e r t a i n area against other members of the same species. In the genus Lagopus t e r r i -t o r i e s are r e s t r i c t e d to the breeding season, and are maintained p r i m a r i l y or e n t i r e l y by the male. T e r r i t o r i a l behavior ( d i s -plays and c a l l i n g associated with the establishment and main-tenance of defended areas) commences early i n spring, u s u a l l y i n l a t e A p r i l or May. The exact calendar time v a r i e s with l a t i t u d e or other phenologic gradients. Willow and rock ptar-migan, at l e a s t , may set up temporary t e r r i t o r i e s very early i n the breeding season, which are defended f o r a few days or even only a few hours. Temporary t e r r i t o r i a l i t y such as t h i s probably occurs with some r e g u l a r i t y i n migratory populations. However, each male normally establishes a permanent area of defended ground which i s used u n t i l the chicks hatch. T e r r i t o r i e s are maintained by a v a r i e t y of methods which can be classed as displays on the ground ( t a i l fanning, s t r u t t i n g , "walking i n l i n e , " wing lowering, e t c . ) , f l i g h t s 29 (involving two or more males, or males and females) and c a l l s . Each species has i t s own set of calls related to courtship and advertisement of territory, although sounds made i n response to fear, those which cause the chicks to hide, the peeping of chicks, etc., may be very similar between species. True "songs," functioning as advertisement, are given only by the male of each species. In a l l three ptarmigan territory defense and other breeding a c t i v i t i e s (as measured by frequency of calls) are most intense at dawn and i n the evening. Watson (1956) gives a more complete discussion of calls and displays in mutus and lagopus. Galls similar to those made during territory advertise-ment and defense are not limited to the breeding season. In the present study several observations were made of willow ptarmigan which called vigorously for short periods i n the dusky hours of the morning and evening i n August and September. In a l l cases the males were i n the company of broods of large young, and one male collected at that time possessed testes which were regressed (as indicated by size). It i s probable that autumnal ca l l i n g i n ptarmigan i s similar to that noted i n several other galliforms and i n many species of passerines. Its meaning and causes are unknown. Population density apparently can affect t e r r i t o r i a l behavior among ptarmigan. Watson (1956) found the usual signs of intensive t e r r i t o r i a l a c t i v i t y among rock ptarmigan i n Scotland: the males defended definite areas, called frequent-l y , displayed actively and indulged i n courtship f l i g h t s 30 involving several individuals. The population density ap-proached one pair per 30-40 acres. At Eagle Creek i n central Alaska, on the contrary, cocks did not appear to defend spe-c i f i c areas against other mutus, but confined their defense to a variable area around the female, no matter where the hen went. The frequency of contacts between males was rela t i v e l y low, so that many types of displays mentioned by Watson were seen rarely. The population of mutus at Eagle Creek i n 1956 did not exceed an average of one pair per 530 acres over an area 25 square miles i n extent. Willow ptarmigan were abundant on the f l a t s of Chilkat Pass, B r i t i s h Columbia, i n 1957 and 1958, with populations of one pair per 13 acres over an area of several square miles. Males defended distinct areas from the second week i n May (when terri t o r i e s were established f i r s t ) to June, when the chicks hatched. The boundaries of eleven terr i t o r i e s were estimated roughly by observing clashes between adjacent males; those defended areas are shown i n Figure 5. The average territory size was 5.2 acres (range 3.5-7.0 acres). At least two t e r r i -tories were held by the same males i n 1957 and 1958 (deter-mined by banding studies). The terr i t o r i e s of ptarmigan probably provide a means of increasing the speed and efficiency of mating by preventing excessive interference i n courtship. The nest usually i s located i n the area defended by the male, at least i n mutus and lagopus. Data on brood movements (see page 42) show that fam-i l i e s of rock and willow ptarmigan wander over an area much 31 mi. mi ...v Shrubby Vegetation (^^5 Open Vegetation CO Diurnal Cover @ Nest X Approximate Boundary of Territory 77' Scale: l "=400' N Size of Territories Number I 2 3 4 5 6 7 8 9 10 I I Acres 4.6 4.6 5.5 7.0 6.9 3.7 3.5 5.9 5.5 5.5 4.6 Figure 5. Territories of II mole willow ptarmigan at Chilkat Pass, British Columbia, 1957. larger than the territory of the male. Male leucurus and mutus may leave their territory before or shortly after the chicks hatch or may remain on i t (without defending i t ) while the brood moves i n or out of the former territory at w i l l . Therefore, the territory apparently does not need to ensure an adequate amount of food for the young as i t may i n some species (for example, Seiurus aurocapillus; Stenger, 1958). Sexual Relationships and Age at Maturity It i s generally thought that ptarmigan are monogamous (for one season only, except i n unusual circumstances), a l -though statements to the contrary have appeared from time to time. Nicholson (1930) suggested bigamy among mutus after seeing a male i n the company of two females near Godthaab Fiord, Greenland. One female had a brood, the other allegedly did not. Scott (1951) saw a male mutus and two hens close together, and presumed that the male was mated to both. In neither of the two cases cited was sufficient proof given that the association was not accidental. Ptarmigan probably breed during the f i r s t spring after hatching, when they are about 10 months old. The evidence for this as a general statement i s circumstantial: there seems to be no large class of non-breeding birds i n spring, although there is often a slight preponderance of males which, presum-ably, have no mates. Information from banding (01stad, 1953, and the present study) indicates that ptarmigan breed i n their f i r s t year. Westerkov's (1950) study of lagopus i n Norway showed that 76 percent of the population i n the f a l l and winter 33 were juvenile birds, and 19 percent were 1.5 years old. Thus, the major portion of the spring population was less than one year old; such a large group of birds, i f not breeding, scarce-ly could remain unnoticed. However, Sutton (1932) and Fitzgerald (1946) suggest, but do not prove, that some ptar-migan do not breed u n t i l two years old. Nesting Ptarmigan always nest on the ground, as do a l l other Tetraonidae. They do not construct an elaborate nest, but usually use materials found i n the immediate v i c i n i t y of the nest to form a shallow, p a r t i a l l y lined cup. Most lagopus and mutus hens nest under some sort of overhanging vegetation (a tendency which i s somewhat stronger i n lagopus), but white-tailed ptarmigan nests rarely are concealed i n that way. Bendire (1892) gives information indicating that willow ptar-migan may use the same nest i n two successive seasons. This appears to be the only time that the suggestion has been made in the literature. Clutch sizes are so variable as to make averages almost meaningless; i t i s possible that annual and latitudinal differences exist within each species, but s u f f i -cient data are not available to prove the point. Information on clutch sizes obtained from an extensive search of the l i t -erature of North America i s presented i n Appendix IV. One brood per season i s the rule among ptarmigan, although second or even third nests (Turner, 1885, i n Bendire, 1892) may be started i f the f i r s t one or two are destroyed. Occasionally, observations of broods with chicks of different 34-sizes have led to the assumption that double broods are raised (Dawson and Bowles, 1909; Porsild, 194-3), but i t seems much more l i k e l y that two broods of different ages and of different parentage combined after hatching. The breeding times of birds i n arctic regions are synchronized as a result of the shortening of the period available for reproduction. A l l species are ground-nesters (except for a few passerines which nest i n shrubs), and nest-ing cannot begin before snow leaves the ground i n suitable areas. Migratory species usually leave the Arctic i n July or August. It i s not surprising, therefore, to find that rock and willow ptarmigan tend to breed at the same time i n high-arctic areas (Watson, 1956). Brood data obtained i n the pres-ent study suggest that there i s remarkably l i t t l e difference i n the breeding times of the three species i n areas where they are found together. Annual variations i n weather affected the time of egg-laying, but such differences influenced a l l species of ptarmigan similarly. For example, the f i r s t broods of mutus, lagopus and leucurus hatched i n Chilkat Pass about June 20 i n 1957. In 1958 the season was phenologically ad-vanced over 1957, and broods of ptarmigan hatched about one week earlier. The effect of seasonal differences i n weather on the nesting of willow ptarmigan, as well as the close synchrony of nesting among individuals of a population, are shown i n Figure 6. The factors probably contributing to the earlier nesting i n 1958 were the light snowfall during the winter of 35 Figure 6 . Dates of patching of nests of willow ptarmigan, Chilkat pass, British Columbia 36 1 9 5 7 - 5 8 , the warm weather i n April and May and the lack of rain or snow i n the period April-June, 1958. (This general weather information was obtained from workers at mile 75 Haines Road, Chilkat Pass, who were present both years. No o f f i c i a l weather stations are present i n the area.) Photoperiod probably has l i t t l e influence on the breed-ing schedule of ptarmigan. The wide range i n latitude and correspondingly great :differences i n length and rate of change of photoperiod i n spring are not reflected i n a la t i t u d i n a l progression of breeding seasons within any one species of ptarmigan. "For example, populations of willow ptarmigan i n the MacKenzie Delta (Northwest Territories), northern B r i t i s h Columbia and southcentral B r i t i s h Columbia apparently nested synchronously i n 1958. Data compiled from the literature and from the present study, summarized i n Appendix IV, show no indication of a photoperiodically controlled breeding season. There i s some annual variation i n the nesting schedule i n a given geographic area, and l i t t l e evidence of progressive northward delay of hatching dates. The data are not conclu-sive, however, as the value of the information i s lessened by the distances and time involved. It i s also possible that each race of ptarmigan reacts to photoperiod i n a sl i g h t l y different way, thereby masking the direct l a t i t u d i n a l effect of l i g h t on breeding. It i s generally accepted that ptarmigan deposit eggs i n nests at the rate of one each day, with occasional two-day intervals between egg-laying periods. Westerkov (1956) gives 37 the egg-laying rate of Norwegian willow ptarmigan as 1.1 per day. He states that the incubation period i s 20-21 days. Bent (1932) and others believe the incubation period to"-be 20-22 days for a l l three species of Lagopus. It i s assumed that incubation begins only after the clutch i s complete, primarily because the chicks i n any one nest hatch within a few hours of each other. However, an interesting observation by Taylor and Shaw (1927) raises the question as to whether this assumption i s always va l i d . Those investigators found a nest of leucurus containing five eggs on Mount Rainier, Washington. They were being incubated when dis-covered. One of the eggs was i n f e r t i l e , another addled and three were reported to be i n various stages of development up to ten days. On two occasions i n 1957, a female willow ptarmigan was observed to "incubate" an empty nest. In each case the eggs had been taken by a predator during incubation. Perhaps broodiness as a behavior pattern was released f i r s t by the f u l l clutch of eggs, and maintained or reinforced by the nest cup and the immediate surroundings of the nest. A point which may be pertinent i s that i n neither case were broken eggs v i s i -ble which might cause the hen to leave. The observations i n d i -cate the strength of incubation behavior i n female willow ptarmigan (although i t i s possible that i n one instance the hen had been preparing to lay again); one wonders how long the hens would have continued to s i t on the empty nests i f undis-turbed, and what effect this might have on the chance for re-nesting. 38 Broods Hatching.—The chicks of Lagopus, like those of other gallinaceous "birds, are precocious. Ptarmigan chicks usually-l e f t the nest within three to ten hours after hatching (Table I ) . Moreover, the time from the beginning of pipping (the pecking of a hole i n the egg by the chick) to the deser-tion of the nest was often 24 hours or less. In a l l cases observed, the hen remained on the nest throughout the hatching period, leaving only after a l l l i v e chicks hatched and dried off. A.small number of chicks died during the pipping process. Out of a total of 68 eggs l a i d i n eight successful nests of willow ptarmigan i n Chilkat Pass i n 1957, 64 hatched. Of the remaining four eggs, one was i n f e r t i l e , while the other three contained chicks which died during pipping. Parental care.—Male willow ptarmigan usually are very attentive to their chicks; rock ptarmigan cocks occasionally may stay with the hen and chicks after hatching, but usually do not. Males of leucurus have never been reported to help i n the care of broods. It i s d i f f i c u l t to decide what this d i f -ference means to the three species. The attendance of broods among male willow ptarmigan may be of special benefit to the species, although i f that were the case, one would think that mutus and leucurus cocks also would exhibit that behavior pat-tern. Perhaps i t i s a neutral character i n lagopus which indicates ancestry more than adaptation. Some other aspects of brood care should be noted b r i e f l y . When ptarmigan chicks leave the nest they may be 39 Table : I. Histories of hatching of rock and willow ptarmigan Location and Brood Number Date Time Remarks R2-56 (mutus) June 19, 1956 11:00 a.m. Female on nest; Eagle Greek, eggs with pipping Alaska holes. June 20, 1956 10:30 a.m. Female and chicks gone from nest. R4-56 (mutus) June 17, 1956 2:00 p.m. Young heard inside Eagle Creek, eggs. Alaska June 18, 1956 2:15 a.m. Female off nest, but nest warm. 1:00 p.m. Female on nest, young not hatched. June 19, 1956 10:40 p.m. Young a l l hatched; possibly hatched about 2:00 a.m. ¥1-56 (lagopus) June 17, 1956 9:45 a.m. Chicks heard Eagle Creek, within egg. Alaska June 18, 1956 3:00 a.m. Female on nest with 9 chicks hatched; young probably hatched around midnight. 7:00 p.m. A l l young out of nest. Wl-57 (lagopus) June 27, 1957 8:00 a.m. Eggs pipping. Chilkat Pass, June 28, 1957 9:00 a.m. 8 eggs hatched, B.C. 2 pipped. 4:30 p.m. Female on nest. 7:00 p.m. Female brooding 9 chicks; remain-ing chick dead. W2-57 (lagopus) June 29, 1957 8:00 a.m. A l l eggs pipping. Chilkat Pass, 9:00 p.m. Female on nest B.C. with young. June 30, 1957 11:00 a.m. Nest empty. W3-57 (lagopus) June 29, 1957 7:40 a.m. Eggs pipping. Chilkat Pass, 6:00 p.m. Female on nest B.C. with chicks. 40 brooded by the hen for a day or two, especially i n times of danger and during cold or otherwise inclement weather. I know of no detailed observations on that aspect of brood behavior i n North American literature, and can only infer from a few personal experiences that i t i s true. Even at a very early age, a run-and-hide reaction seems to be strong among ptarmi-gan. On several occasions I found a willow ptarmigan nest when the hen was brooding the young either on the nest or close by; as soon as the hen moved off the chicks, the young either scattered and hid i n vegetation or attempted to remain with the parent. The hen, too, seemed torn between the apparent need to urge the young to hide and an instinct to protect them with i t s own body. Behavior associated with brooding (on the part of chicks and adult female) quickly waned, however, and the tendency to hide dominated for about ten days, after which i t , i n turn, was replaced by a tendency to f l y away from danger. Another point of interest i s the extent of the bond between male lagopus and the chicks. It was found i n some broods at Chilkat Pass that both sexes actively defended their young with clucking, injury-feigning (distraction) and occa-sional attacks on the human intruder. However, i n a majority of cases one of the parents was more active i n defending the brood. In such families the same parent played the prominent role each time the brood was disturbed. There seemed to be no tendency for one sex to do this more than the other. One male lagopus remained with a brood of nine-day-old chicks for sev-eral days after the female had been collected. 41 Males were seen only three times i n a total of 50 observations of 32 broods of rock ptarmigan at Eagle Creek, Alaska. On those three occasions (two of which were late i n the evening) the cock flew off as soon as the observer approached. No males participated actively i n brood defense, although the hens were f u l l y as solicitous as those of lagopus. Observations of mutus broods i n Greenland (Salomonsen, 1950u) indicated that males l e f t the hen just before the chicks hatched, only to rejoin the broods i n August when the young were almost f u l l y grown. That may be true, but there seems to be no basis for the implication that males rejoined the same females with which they bred. The conjoining males and broods i n late summer may be simply the start of f a l l flocking. Stud-ies of marked birds are needed to prove the point, however. Movements.—Quantitative data on movements of ptarmigan broods are scarce i n the literature, especially for mutus and leucurus. Studies of willow ptarmigan i n Norway (Olstad, 1953) showed that young birds banded i n summer usually were recovered in the f a l l close to their banding place. In my own research, information was obtained on family movements among lagopus (in Chilkat Pass, B r i t i s h Columbia, i n 1957) through the use of adults marked with dye on their white primaries. Data obtained this way are summarized here. The travels of broods of lagopus were cla s s i f i e d into three categories: net brood-season movements, short-term movements and movements caused by disturbance. "Net brood-season movement" i s the total distance i n a straight line between the f i r s t observation (usually made when the chicks were less than two weeks old) and the last observation of the brood. In general, the f i n a l record was obtained i n the f i r s t part of August, after which many families dispersed. Fifteen marked broods were observed over a sufficient period to yield data on net brood-season movements (Table I I ) . It should be emphasized that the distance between the f i r s t and last obser-vations does not bear any relation to the total distance a family may have moved i n the interim. TABLE II. Net brood-season movements of willow ptarmigan at Chilkat Pass, B r i t i s h Columbia, 1957 Brood Number F i r s t Observation Last Observation Days Distance Moved i n yards W 1 June 28 August 11 45 200 W 3 June 30 July 19 20 200 ¥ 7 July 2 July 27 25 75 ¥10 July 3 August 9 37 300 ¥11 July 4 August 2 29 600 ¥13 July 4 August 28 49 40 ¥18 a July 5 July 29 24 200 W18b July 8 August 5 26 100 ¥23 July 3 July 24 21 200 ¥24 July 8 Augus t 17 40 400 ¥25 July 8 August 4 27 200 ¥29 July 11 August 10 30 100 ¥30 July 11 August 2 22 400 ¥40 July 15 August 10 26 50 ¥43 July 19 August 9 21 100 Average 29 190 43 There i s a considerable difference between the short-est (40 yards) and longest (600 yards) distances moved. The brood observed over the longest period of time (W13) was also the one seen closest to the point where i t was found o r i g i -nally. One important source of bias i n the data i s that only those broods which were seen over a three- to seven-week period were included. Those which were not found after the early part of the brood season may have travelled the greatest distances i n net movement, as they may have gone beyond the boundaries of the study area. On the basis of these data, i t appears that most families of lagopus showed no tendency toward pro-longed unidirectional movement, but travelled more or less at random i n a restricted area. The same general conclusions are borne out by an exam-ination of short-term movements, l i s t e d i n Table III. "Short-term movements" are defined as those taking place over a period of 2-18 days. Distances travelled by broods within 36 hours after being flushed are considered to be i n the "disturbance movement" class of data. Table III reveals a great v a r i a b i l i t y i n the amount of movement per unit of time. For example, brood ¥19 travelled 1 ,000 yards i n one 11-day period; i n the same length of time ¥3 moved 50 yards (net distances given). 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As was true of net brood-season movements, there i s no way of knowing how far each brood may have wandered between observations. Two of the broods l i s t e d i n Table IH were observed a sufficient number of times to allow further analysis of their movements. The wanderings of those broods (¥7-57 and ¥29-57) are depicted i n Figures 7 and 8. For each brood, consecutive observations were plotted so that the distance and relative direction of movement were shown. The "coordinates" of each observation were then l i s t e d , added together and divided by the total number of sightings. The resulting pair of "coordinates" was designated as the "center of movement." The center of move-ment has no biologic r e a l i t y , as the brood may never have been there, but i t does allow easy numeric comparison of the move-ments of broods. The average distance for observations of ¥29-57 from the "center" was only 80 yards; ¥7-57 moved i n a radius of about 225 yards from the center. If based on enough observations, this method should clearly indicate the extent of the range of each family group. When a brood was found on the tundra i t invariably was disturbed. The disturbance resulted i n movement, the extent of which was determined by the degree of disturbance and the age of the chicks. A few data were gathered on the distances travelled by lagopus broods after flushing, and are presented here: 47 4 - July 28 5 - August 2 6 - August 5 7 - August 8 8 - August 10 I I 2 3 Scale: I inch = 100 yards Figure 7. Movements of marked broods of willow ptarmigan, Chilkat Pass, British Columbia, 1957: W 7-57 48 Roure 8. Movements of marked broods of willow ptarmigan, Chilkat Pass, British Columbia, 1957: W29-57 49 Brood Dates Time After Flushing i n hrs. Distance i n yds. W 1 July 27 12 150 ¥ 3 June 30-July 1 29 100 ¥ 7 July 2-July 3 25 120 July 24 2 30 ¥ 8 July 18 2 200 ¥15 July 9-July 10 21 0 July 10-July 11 27 80 ¥29 July 27-July 28 31 0 ¥30 July 11 14 60 Average 18 82 According to the data available, there i s a great v a r i -ation i n distances moved by broods of willow ptarmigan from the time of hatching u n t i l late summer. Some families wandered up to one-half mile from their nesting site i n one week, while others moved around i n areas only a few acres i n extent. There was some indication of concentration of broods i n two or three favorable locations within the one-sqjuare-mile study area, but no general unidirectional movement on the part of the popula-tibh. A similar situation apparently existed with mutus at Eagle Creek, Alaska. Early i n the brood season families were found repeatedly on the same slope or i n the same high valley, often near their nesting place. In July, most broods drifted toward the tops of the rounded h i l l s , and several were found on moist, grassy, shrubless "saddles" between summits i n August. No data are available for movements of broods of leucurus. 50 In general, two opposing pairs of factors may affect the movement of ptarmigan broods of a l l species. F i r s t , adults lose certain ties that they may have had to a specific plot of ground. The males cease to defend t e r r i t o r i e s after the chicks hatch, and females no longer have the nest as a focal point of act i v i t y . On the other hand, there may be a tendency for adults to stay i n areas familiar to them even after the chicks hatch. Second, families of ptarmigan have certain requirements for food and shelter which they w i l l move considerable dis-tances to find i f necessary. However, i n the areas vis i t e d i n the present study, suitable brood cover often was contiguous with (or part of) vegetation i n which the hens nested. Thus, the variable mobility of ptarmigan may be explained on the basis of changes in the degree to which each of those factors i s operating. Growth and development of chicks.—The precocity of young ptarmigan, f i r s t shown by the rapidity with which they leave the nest, i s demonstrated by their speed of development, especially of the feathers used i n f l i g h t . Data from studies of marked broods of known age show that chicks of mutus and lagopus (and probably leucurus) can f l y at least a few yards by the ninth or tenth day after hatching. Most gallinaceous birds are capable of short f l i g h t s when 12-14 days old. Further details of development are available only for lagopus. However, the other species of ptarmigan probably are very similar. Data compiled by Westerkov (1956) from studies of willow ptarmigan i n Norway are summarized i n Table IV. 51 Table IV. Development of chicks of willow ptarmigan Development up i to 18 Days Age i n Wing length Weight Days i n mm. i n gm. 1 20 - 24 14- 15 2 .20 - 26 15- 16 4 31 - 43 20- 25 6 44 - ? 52 28- 30 8 52 - 62 30- 37 10 65 - 80 41- 49 12 70 - 79 47- 59 14 64 - 90 65- 73 16 65 - 88 89 18 96 - 105 77-100 20 95 - 110 108-117 Development from 18 Days to 9 Weeks Primary Age Dropped Number in weeks 1 2. 5 2 3. 5 3 4.0 4 5.0 5 6. 0 6 6. 5 7 7. 5 8 9. 0 Size of Chicks After 9 Weeks One-quarter grown (as indicated by weight and over-all size) at 10 weeks One-half grown at 11 weeks Three-quarters grown at 12 weeks Pull grown at 13 weeks Data compiled from Westerkov, 1956. 52 As the f i r s t primary (the one closest to the body) i s shed when the chick i s 18 days old, Westerkov used wing length for age determination i n lagopus instead of primary length. Between the ages of 18 days and three months, age was determined "by the replacement of juvenile primary feathers number 1-8. It should be noted that the overlap i n wing measurements of chicks under 18 days old i s greater than that of the weight of the same chicks. Perhaps weight would be a more accurate cr i t e r i o n of age i f the weight/age correlation were worked out i n each popu-lation to correct for regional differences. Some further details of development from observations made i n the present study are summarized here: 1 day: At hatching, chicks were covered completely with down except for the toes. No primaries were v i s i -ble on the stubby wings, although occasionally very tiny sheaths showed where feather papillae were growing through the skin. The weights of five one-day-old chicks collected i n 1958 were 14.0, 14.6, 14.7, 15.1 and 15.5 grams (av. 14.8 grams). 3 days: Primary shafts were v i s i b l e , s t i l l completely sheathed and tipped with down. Two chicks of this age weighed 16.4 and 17.7 grams. 4 days: The sheath oh the primaries was about one-half inch long, with an additional one-quarter inch of feather vane showing. 6 days: Primary sheaths were about one-half inch long, with one-quarter to one-half inch of feather 53 v i s i b l e . Three chicks (five, six, and seven days old) weighed 21.7, 18.2 and 22.0 grams, respec-ti v e l y . 7 days: The total length of primaries was about 1% to 1% inches, with a sheath about one-half inch long. 9 days: No t a i l feathers were present at this age, a l -though i n a few cases they were just v i s i b l e . The primaries are Vk to 2 inches i n length. 10-11 days: Chicks flew for a few yards, but preferred to run and hide. The flank feathers were starting, and the t a i l coverts were one-quarter inch long. The weights of four chicks i n this age group were 31.8, 34.3, 38.7 and 44.9 grams (av. 38.4 grams). 12 days: The young flew a short distance when flushed. 13-14 days: The t a i l coverts were about one-half to three-quarters inch long, with wing feathers 2-2% inches i h length. The f l i g h t of the young was wobbling, and they usually landed within 50 yards of the point of flushing. 16 days: The chicks were s t i l l too small to band with standard (No. 5) aluminum bands which f i t the adults. Wing feathers were at least 2% inches long, and t a i l coverts were up to three-quarters of an inch long. 17-18 days: The complement of wing feathers was nearly com-plete, including the coverts. Primaries were 2}£ - 3 inches i n length. 54 18-19 days: The young were just large enough to band without flattening the band. 22-24 days: T a i l coverts were from 1 - lK inches long. Tiny feathers showed on the back, as well as a few on the crown of the head. Primary feathers were 3# - 4 inches, with the wing complete except for primaries number 9 and 10 (counting d i s t a l l y along the wing). 24-26 days: The third primary was replaced by a white primary; coverts one-half inch long were present under the wing. White pinfeathers were present on the belly, and feathers were v i s i b l e on the breast, flanks and crown. T a i l coverts were Vk inches long. 30-32 days: Wings showed a considerable flash of white when the young flew, as primaries number 10, 5, 4 and 3 were white. The belly also appeared whitish, due to the soft, white, down-like feathers there. Under-wing coverts were three-quarters of an inch long, and the t a i l was about two inches i n length. Chicks of this age weighed about 150-170 grams. Food and Feeding Food Ptarmigan are primarily herbivorous, especially as adults. Although few intensive studies have been made corre-lating crop analyses with vegetation, i t appears that a v a i l -a b i l i t y plays a large part i n the selection of foods by ptarmigan. Many items appearing i n the diet of Lagopus spp. i n a certain region may be lacking i n the f l o r a of another region (as shown later i n Table X). A f a i r l y large proportion of the plants present i n any given tundra area appear i n the diet of ptarmigan at one season or another. In general, the only items not ingested are stems of plants too thick to break off, the dry blades of graminoids, items too small to pick up and the ligneous parts and evergreen leaves of certain Ericaceae and similar plants. However, a v a i l a b i l i t y i s not the sole determinant of diet among ptarmigan. The phenomena of preference and avoidance both are exhibited i n the food habits oft.it.hese birds. For ex-ample, the leaves and buds of Salix spp. seem to be preferred over some other types of food which are equally available during most of the year. After a very thoughtful analysis of the feeding behavior and diet of mutus i n Greenland, Gelting (1937) showed that rock ptarmigan possessed a definite prefer-ence for the bulbils and tubers of Polygonum viviparum. On the other hand, willow ptarmigan i n Newfoundland avoid the Ericaceae Kalmia angustifolia as food, although they frequently nest i n stands of that shrub (Peters, 1958). Similarly, ptar-migan (mutus and lagopus) observed i n my own studies rarely ate the leaves or other parts of Betula glandulosa i n summer, a l -though the buds and catkins of that common arctic-alpine shrub often were taken i n winter. The buds and needles of conifers rarely are eaten by ptarmigan, although a l l species of Lagopus often spend the winter near stands of coniferous trees. White-56 tailed ptarmigan occasionally eat buds and needles of conifers particularly when the snow covers other sources of food (Quick, 1948). Two male rock ptarmigan were collected i n central Alaska, December 6, 1953, whose crops were f u l l of spruce buds. The two birds are in the collection of the Department of Zoology, Washington State University, Pullman. This i s the only instance known to me of the occurrence of conifer material in the crops of mutus or lagopus. The young of most gallinaceous birds eat a greater pro-portion of insects than the adults, especially i n the f i r s t two weeks of l i f e . That tendency i s present among ptarmigan, a l -though perhaps to a lesser extent than with forest or plains dwelling galliforms. At present, with such a small number of very young chicks of the various species collected, i t i s im-possible to generalize about the food of young ptarmigan. In the most extensive study to date, Lid and Meidell (1933) found that insects formed 50 percent of the diet of young willow ptarmigan up to the age of nine days. Moss capsules and Vaccinium flowers were the favorite plant foods. On the other hand, Polunin (1949), quoting Rand (in l i t t ) stated that "An interesting thing about ptarmigan i s that while the young of most plant-eating birds feed on inseets, this seems less true of ptarmigan than almost any others, and young ptarmigan seem to be nearly as plant-eating as the adults." Other scattered references to the food of ptarmigan chicks indicate a similar v a r i a b i l i t y . Data from the present investigation are not analyzed f u l l y as yet. However, i t appears that i n general Rand's suggestion w i l l be supported. For example, vegetable material (mostly flowers, f r u i t and twigs of Vaccinium, Polygonum bulbils, seeds of various graminoids and moss capsules) formed 62 per-cent by weight of the crop contents of seven chicks of lagopus from one to five days of age collected i n Chilkat Pass, B r i t i s h Columbia. Animal material (mostly Diptera) formed less than one percent of the food. Grit made up almost 38 percent of the weight of the material i n the crops. Plant material was present i n a l l crops, while animal material was absent from three. The crops of two white-tailed ptarmigan chicks (age 10 days) c o l -lected i n central B r i t i s h Columbia contained 80 percent vege-tation and 20 percent animal matter (by weight). Many factors may have contributed to the low degree of specialization i n the food relations of ptarmigan. The lack of severe competition from other avian herbivores may be im-portant; any intraspecific competition for food arising from high population densities probably would tend to promote v a r i -a b i l i t y i n diet, rather than specialization. The hetero-geneous character of the tundra undoubtedly i s important. Certain of the plants eaten by ptarmigan have a very wide lat i t u d i n a l and alt i t u d i n a l amplitude (many willows, for ex-ample). There are few extensive pure stands of any vegetative type i n the tundra, primarily because of the sens i t i v i t y of plants to small changes i n moisture and snow cover, and to the interaction between plants and the heaving and slumping of s o i l . Another factor i s the rela t i v e l y large size of ptarmigan, com-bined with the vegetational heterogeneity mentioned above. 58 Forced seasonal changes i n the diet may he important also, as they might prevent some morphologic or physiologic specializa-tions i n the digestive system of ptarmigan. Grit Grit i s important to a l l gallinaceous "birds as an aid i n the mechanic breakdown of food particles i n the gizzard, and possibly as a source of minerals such as calcium. Ptarmigan may pick up—small amounts of g r i t daily when i t i s available (quartz seems to be preferred i f present), and may have the a b i l i t y to retain g r i t i n the gizzard for long periods during winter when the ground is covered with snow. It i s puzzling that ptarmigan ingest g r i t frequently i n summer, but seem to be able to get along without i t i n winter, when ligneous mate-r i a l i s so important i n the diet. Peters (1958) suggested on the basis of evidence obtained i n Newfoundland that the hard seeds of Rubus chamaemorus, Maianthemum canadense and Oornus  canadensis may be used as g r i t . The problem i s discussed by Kolderup (1924) i n relation to Norwegian willow ptarmigan. A recent experiment by Rajala (1958) suggests that ptarmigan may ingest a large amount of g r i t voluntarily just before snow cover becomes continuous, and retain large pieces of stone for extended periods. However, the question i s not solved, and should be subjected to further study. Water There i s a tendency among investigators to dismiss the importance of water to birds i n north temperate and arctic 59 regions on the assumption that free water is never lacking or is not a dietary necessity to species eating flesh or succu-lent plant material. Perhaps this i s ju s t i f i e d , at least i n the majority of cases. Ptarmigan undoubtedly obtain water from the consumption of snow i n winter, from berries i n summer and f a l l , from green plants i n summer and from dew and other sources of free water over most of the year. However, i t was noted i n the present study that each species of ptarmigan was l i k e l y to concentrate around wet areas i n summer, particularly after the chicks have hatched. White-tailed ptarmigan habitu-a l l y fed and loafed near melting snowbanks, surface seepage or alpine pools. L. mutus broods concentrated i n seepage areas at the head of valleys, moist "saddles" on ridges and gravel-ly streambanks; families of lagopus were much more frequent near marshes and streams than i n dry sites within their gen-eral zone of occupancy. These distribution patterns can be explained i n terms of food and shelter provided by vegetation i n moist areas, but i n the absence of proof the p o s s i b i l i t y that free water i t s e l f is attractive cannot be disregarded. There are scattered suggestions i n the literature that water may be important. Bailey (1928) speaks of the apparent need of female white-tailed ptarmigan for water, Watson (1956) states that ptarmigan i n Scotland seek water during summer or winter droughts, and Glstad (1953) says that i n dry summers there i s some lowering of production due to i n f e r t i l i t y or death of embryos. 60 Feeding The times that ptarmigan, feed are not well known. In winter they probably forage throughout the brief hours of day-light, and return to snow roosts or other shelter at night. During seasons when periods of darkness and lig h t are about equal, ptarmigan apparently prefer to feed early i n the morn-ing and, to a lesser extent, late i n the afternoon. When day-light i s continuous, or nearly so, the tendency to feed at dawn and evening must be modified somewhat; however, our knowledge of summer feeding periodicity among birds at high latitudes i s meager. Predation and Parasitism Ptarmigan share with Collembola, eertain other insects, a few rodents, arctic hares, caribou and musk-oxen the role of primary consumers of plant energy i n tundra communities. As such they are important sources of food to arctic-alpine preda-tors, including man. In some northern regions, when snow hides the a c t i v i t i e s of small rodents, and when herds of ungulates are absent, flocks of lagopus and mutus may be the only source of food for the few predators that remain i n winter. White-tailed ptarmigan probably are less important i n this respect, due to their relatively low numbers, the r a r i t y of large flocks in winter and the movement of many predators out of high alpine areas in the f a l l . As far as I am aware, there have been no quantitative studies of the effect of predators on ptarmigan populations. General references to predation, based on scattered observa-61 tions, are frequent i n arctic literature; one can find refer-ence to the hunting of ptarmigan by nearly a l l predatory mammals and birds found i n places where ptarmigan l i v e . In addition, periodic fluctuations i n the numbers of ptarmigan have been ascribed to predation pressure, just as to sun spots, weather, diseases, parasites and food quantity and q u a l i t y — and with equal lack of evidence. It is possible that when flocks of ptarmigan feed on a spatially-confined food supply near places providing shelter to predators, predation might result i n excessive mortality among ptarmigan. In local areas around villages, human exploitation may hold populations of mutus and lagopus at a low le v e l . A', l i s t of some parasites recorded from ptarmigan, together with frequency of occurrence when known, i s given i n Appendix III. In North America, there i s no evidence that parasites act as a population control; i n fact, most ptarmigan are remarkably free of parasites at a l l seasons of the year. Occasionally, individuals with heavy parasite infestations have been collected, and some evidence of parasite-caused f a t a l i t i e s was reported from Norway (Brinkmann, 1923). In the Br i t i s h Isles, an infection of Trichostrongylus was associated with periodic declines of red grouse (anon., 1912), but other factors relating to crowding and weakning of the birds on the winter range were involved as well. Holt (1952) reported sev-eral kinds of parasites from willow ptarmigan in Norway, but after examining 4,000 specimens, he could find only three that showed pathological conditions due to coccidial infections, 62 and a few i n which attacks by the tapeworm Wienlandia microps may have been f a t a l . The problems of parasites in the Arctic are two-fold; they must avoid or withstand long, dry, cold winters, and must contend with a scarcity of hosts. Although various morpho-logic adaptations allow some parasites to circumvent the for-mer d i f f i c u l t y , the low density of suitable vertebrate and invertebrate hosts imposes a r e s t r i c t i o n which i s not easily overcome. As a result, parasites are found i n low numbers i n the Arctic i n most cases, both with regard to the number of hosts infested and the numbers of parasites per host. It is probably only i n unusual circumstances that heavy infestations are l i k e l y to occur. Molts, Plumages and Other Morphologic Features Adult ptarmigan undergo three molts annually: (1) a molt to autumn plumage, corresponding to the annual complete molt i n other birds; (2) a molt to winter plumage, which i s unique among Tetraonidae and rare i n the class Aves; and (3) a molt into summer plumage. Due mainly to the efforts of Dwight (1900) and Salomonsen (1939) there are excellent descriptions of the molts of Tetraonidae i n general and of lagopus mutus i n considerable detail, so that there i s no need to discuss those aspects i n the present report. Hagen (1936) and Watson (1956) have described the plumages of lagopus quite thoroughly. The molt pattern in leucurus has never been stud-ied intensively. 63 Very l i t t l e i s known beyond the purely descriptive aspects of plumage changes. Salomonsen (1939) was able to correlate quantitative temperature changes with the molting rhythm i n rock ptarmigan, and his conclusions were substanti-ated by Watson (1956) for willow ptarmigan. Salomonsen (1939» p. 424) concludes: The state of moult i n my opinion i s the result of an interplay between influences originating from the environmental stimuli and a special inherent moult-rhythm which periodically induces a disposition to moult. The moulting rhythm i s not fixed and cannot induce a moult without the presence of the environ-mental (temperature) stimulus, which under normal circumstances i s the only factor capable of releasing the moult. If, however, the bird i s withdrawn from the temperature-impulse the moult probably cannot be entirely suppressed, and, similarly the moulting rhythm w i l l be somewhat resistant i f the annual temperature cycle i s violently changed, and cause the adjustment of the moult to be rather lagging. The author relates various hormonal controls to the "inherent moulting rhythm" mainly by applying the results of experiments on other birds to ptarmigan. Host (1942) succeeded i n inducing molt and egg-deposition among captive ptarmigan i n January and February by supplementing daylight with a r t i f i c i a l l i g h t i n November and December. A close relationship was found between molt and re-production; the start of egg-laying could be predicted by the advancement of the hen's summer plumage. However, these re-sults do not indicate that light is. the factor which triggers molt i n natural environments. They probably mean that plumage development i s affected by the quantity of reproductive hor-mones i n the blood, which i n turn can be influenced by drastic light changes. The best correlation i n nature i s with 64 temperature changes, not lig h t (Salomonsen, 1939). Salomonsen i s of the opinion that snow cover has no effect on winter or summer molts, giving as evidence (in part) that ptarmigan are white longest i n the extreme north, where snow cover i s scanty. In the south the birds may change color before snow f a l l s i n autumn, or before i t melts in spring. He states further that i n most polar animals whiteness is not an. adaptation to snow cover, but i s a thermoregulatory adjustment. However, i t i s probably not whiteness that i s most important for increasing the insulatory effect of plumage i n winter. The greatest heat-conserving benefits are derived from an increase i n the size, number and thickness of feathers and aftershafts. According to Salomonsen, the breast, flanks, rump and crown are areas possessing a greater insulatory effect i n winter than i n summer. Therefore, whiteness does not seem to have been the selection-directing benefit derived from winter plumage, and i t i s not surprising that the donning of winter plumage i s not correlated perfectly with snow conditions. Nevertheless, i t i s reasonable to assume that whiteness i s of some importance i n making ptarmigan less v i s i b l e to other species i n winter. The two factors of cryptieism and temperature regulation probably are involved i n the change to a thinner, browner plum-age i n spring or summer. Salomonsen i s c r i t i c a l (and, I believe, correctly so) of the suggestion that each step i n the molt from winter to summer to autumn plumage i s determined by or adapted to progressively changing requirements of protective coloration. '65 Nevertheless, 'brown "birds are more d i f f i c u l t to see i n summer on the tundra than white birds, and to this extent protective coloration i s of benefit. The t a r s i and toes of ptarmigan are completely and densely feathered i n the period from late September to May. The feathering i s associated with the need for walking over loose snow and with the need for decreasing heat loss i n the extremities. In late winter and early spring the feathers on the toes wear away u n t i l only shafts are l e f t ; the shafts are remarkably s t i f f , and probably s t i l l function as "snow-shoes" even though their insulating a b i l i t y may be slight. Two other morphological peculiarities of ptarmigan should be mentioned: the length of the toenails and the occurrence of pads on the toes. The toenails of ptarmigan are longest i n winter and probably are very useful digging instruments when the snow i s crusted. The nails are shed annually i n late July or early August, at the same time the outer sheath of the upper mandible i s replaced by a new one. The most d i s t a l pad on the lower surface of the toe tends to be flattened i n a l l species of ptarmigan, presumably as an aid i n walking over ice and hard snow, especially when the feather-ing on the toes i s not complete. In leucurus, small, epidermal projections (1-3 mm. i n length) protrude from the sides of this pad, forming a comb-like row called the "peeten." The projec-tions are longest i n spring and early summer. It i s d i f f i c u l t to determine the function of the pecten; similar but much larger structures are present on the toes of many Tetraonidae, 66 so that they do not appear to he primarily an adaptation to the arctic-alpine environment. There i s a tendency for ptarmigan to he larger i n the north than i n the southern part of their range (Watson, 1956). Perhaps the most striking example is the difference between rock ptarmigan i n Spitzbergen, where birds of 1,000 grams have been collected and many weigh as much as 800 grams (Johnsen, 1941), and subarctic areas such as B r i t i s h Columbia and central Alaska, where adults collected i n the present study weighed between 320 and 460 grams (see Appendix II). Presumably, such differences stem from the thermodynamic advantages of large forms over smaller ones of the same species wherever low temperatures must be withstood. There are exceptions to this generalization i n the genus Lagopus, however. Por example, the Siberian form L. lagopus major, which lives south to 50° North Latitude, i s larger than L. 1. koreni, whose range i s further north i n the same region (Johansen, 1956). 67 DESCRIPTION Off PLACES IN WHICH PTARMIGAN LIVE As herbivores, ptarmigan depend directly upon plants as sources of food and as important components of a place i n which to l i v e . Consequently, vegetation has received the most attention i n this study. Moreover, emphasis was placed on vegetation structure (physiognomy) rather than f l o r i s t i c s , as the form of vegetation ( i t s height, dominance, and the physi-cal relationships of i t s components) seemed more l i k e l y to be correlated with the distribution of ptarmigan than the plant species present. ffor leucurus, microterrain and topography are equally as important as vegetation i n their effect on dis-tribution, so that data were obtained on these features of the environment of white-tailed ptarmigan. The relations of each ptarmigan to vegetation and topography w i l l be discussed separately. The f i r s t part of the discussion of each species deals b r i e f l y with the broad zone of tundra occupied. Pertinent information on the charac-t e r i s t i c altitudinal, topographic and moisture relations of each zone are included i n this introductory section, along with some mention of other vertebrates typical of the zone i n summer. The second section i s a description of areas actually occupied within the general zone, including diurnal covers, nesting sites and brood covers. Within the general zone of occupancy, each kind of ptarmigan avoids certain habitats; those are de-scribed i n the f i n a l section of the discussion of each species. 68 Methods The emphasis of this section i s on the presentation of quantitative data obtained through the use of standardized sur-vey methods. However, i t is admittedly not possible at present to rely completely on such material to describe the places where ptarmigan l i v e . The survey data have to be interpreted and their limitations discussed. In addition, the writer gained certain impressions of various features of the landscape which became associated with the presence of a certain kind of ptarmigan. Many of these impressions could not be reproduced i n the form of diagrams or numbers; nevertheless, they have been included i n the hope that others w i l l be able to relate them to their own knowledge of arctic-alpine regions. A standardized method was used to describe the vege-tation i n a l l nesting sites of ptarmigan. When a nest was located, the coverage and height of each major plant species within a 10-foot radius of the nest were recorded. "Coverage" i s the percentage of the total ground surface covered or dominated by a given species or group of species as determined by ocular estimate. A typical plot recorded i n this way might appear as i n Figure 9« The height of shrubs and herbaceous plants was recorded as a range which included the majority of individuals of a species. For example, the dwarf birch shrubs (Betula) i n Figure 9 might be recorded as 1)£ - 2% feet i n height. The largest graminoid stems were ignored, as the f r u i t i n g stems were often twice as t a l l as the more abundant vegetative stems. 69 Coverage Estimate C r^ -Open Type Shrub3 Carex spp. 3 0 % Solix spp. _ _ . 3 0 % Mosses 5 % Beta I o 2 0 % Potentilla 1 5 % Figure 9. A typical nesting site of willow ptarmigan, showing the method used to describe vegetation. 70 The smallest shrubs were not recorded when they formed only a minor portion of the total shrub cover, but the t a l l e s t ones were included, as they usually covered the greatest area as well. Certain structural features of the vegetation are not described when this method i s used. Ground vegetation, such as moss, lichen, Arctostaphylos, Salix recticulata, etc., entered the estimate only when i t was not overtopped by grassy or shrubby plants. In most plots i n willow and rock ptarmigan habitat the ground was covered completely with such low-lying vegetation. An estimate of 5 percent coverage for moss, there-fore, conceals the fact that bryoids might cover 100 percent of the ground surface. For the purposes of the present study i t seemed more important to know that 5 percent of the area of the plot was extremely open. The same was true, to a lesser extent, of the estimate of graminoids and forbs, which often formed an intermediate stratum under shrubs. The f l o r a l composition of nesting sites was treated rather superficially by this method. The term "willow" denotes a genus which has many species i n tundra areas; "grass" includes a number of genera. In the same way, "sedge" may include Carex, Scirpus, Juncus, Eleocharis, Eriophorum or Kobrezia. Herbaceous species often were not l i s t e d i n the vegetation description, as flowering forbs usually were small (from 4-10 inches), scattered i n distribution and overshadowed i n bulk by other types of plants present. At the time when ptarmigan were nesting, few forbs had appeared and fewer s t i l l had reached 71 f u l l size. The most common early-flowering species, such as Dodecatheon frigidum, Anemone parviflorum and Bryas spp., are small, and (in the f l a t s of Chilkat Pass) rarely form dense stands. The subjective nature of the method may have intro-duced some bias. The percentage of the area covered by the various plant categories and height of plants were estimated by eye. As a result, a systematic error i s possible. However, the inaccuracy of the technique was reduced by certain of i t s features: (1) the same person carried out a l l of the e s t i -mates; (2) no attempt was made to estimate coverage closer than 5 percent ( i f the area dominated by the plant was small) or 10 percent (if. the area was larger); (3) heights were expressed as a range i n the original estimate, rather than as a single figure; and (4) the total area of each plot was small, so that the whole plot could be seen at once. The type of plot described above was used i n 1957 as the basic unit i n a transect, the purpose of which was to demonstrate changes i n vegetation form with changes i n a l t i -tude. On a typical transect (Chilkat Pass, August), 43 plots were sampled at intervals of 50 yards. The total distance was approximately one and one-fifth miles; the transect started near timberline and ended at the foot of a glacier 1,100 feet higher. It was found that an unnecessarily large and unwieldy amount of data was obtained which had to be condensed before a simple, accurate and comprehensible picture of the change i n vegetation physiognomy was secured. Therefore, the method was 72 abandoned i n 1958. The method of describing vegetation that was decided upon was a modified version of the pictorial, imethod of Dansereau (1957, pp. 14-7-152). A series of symbols, each standing for a particular form of plant, was devised (Pig. 10) and a notebook was organized to allow the recording of three plots i n diagram form on one page. The horizontal axis of the page represented the percentage of the plot covered by each group of plants, and the v e r t i c a l axis represented the height of the plants. As shown i n Figure 11, this method had the ad-vantage of recording smaller species (herbs, bryoids) i n full,"; regardless of whether they were overtopped by other species. The plots were sketched on the right-hand side of a cross-sectioned notebook; on the opposite page, data were recorded on altitude, slope, height of the plants and the coverage of each major species. A par t i a l l i s t of plants, covering a l l important species i n the plot, was included i n this space. ' Areas were chosen for sampling i f they were represen-tative of a distinct plant community or i f ptarmigan had been found there.- In this way unnecessary duplication was avoided, and more areas could be sampled i n the time available than i f r i g i d l y standardized transects had been run. Willow Ptarmigan General Characteristics of the Zone Occupied Willow ptarmigan occupy the zone of t a l l shrubs within the tundra biome. In southern areas such habitats are found i n 73 Tree Shrub Forb (over 6') ( 6 " to 6') Grominoid Heoth or Shrub (less than 6") Bryoid Examples: Trees - Populus, Picea, Abies Shrubs Solix, Shepherdio, Befulo. Alnus, Potenfilla Forbs Verotrum. Dodecotheon, Senecio, Oxytropis Grominoid Poo, Festuco, Corex, Eleochoris, Juncus Heaths Cassiope, Empetrum, Salix reticulata, Voceiniurn Bryoid Mnium, Sphagnum, Clodonio, Dryas ( the latter is included because of its invariobly low form ) Figure 10. Symbols used in plant surveys, 1958. 74-Figure It. A typical plot recorded by survey method used in 1958. 75 narrow, often discontinuous "belts on mountain slopes. On the northwest coast of Alaska and i n similar coastal areas i n the Arctic, the zone may be many miles i n width. The zone of t a l i shrubs flourishes under the warmest and most moist climate of tundra, and the vegetation i s the most luxuriant found i n arctic-alpine areas. The relatively high production of plant materials, i n turn, means that willow ptarmigan are capable of reaching a higher density than either of the other two species of Lagopus. At the southern l i m i t of i t s range i n western North America (southern B r i t i s h Columbia) lagopus i s found at a l t i -tudes of 6500-7200 feet; in Newfoundland (at the latitude of Washington State) the most southerly populations of lagopus li v e only a few hundred feet above sea level. In areas border-ing the Arctic Ocean the same species i s found at sea l e v e l . The areas i n which lagopus i s found are usually more moist throughout the summer than places occupied by mutus or leucurus. There i s no way of knowing whether moisture has an i n t r i n s i c value to willow ptarmigan not shared by the other species, or whether moisture i s merely another factor associ-ated with, and partly responsible for, the development of the type of vegetation preferred by willow ptarmigan. Willow ptarmigan share the zone of t a l l shrubs with a large number of resident or migratory birds and mammals. In marshy areas, lesser yellowlegs (Totanus flavipes), dowitchers (Limnodromus griseus and L. scolopaceus) and gulls (Larus spp.) are encountered frequently. In more mesic sites, savannah 76 sparrows (Passerculus sandwiehensis), tree sparrows (Spizella  arborea), redpolls (Acanthis spp.) and Wilson warblers (Wilsonia pusilla) nest i n abundance. Moose (Alces alces) use the moist, shrub-covered portions of the zone i n summer i n alpine areas, and ground squirrels (Citellus parryi), Microtus spp. and Dicrostonyx sp. often are common. Occupied Areas A l l areas i n which the presence of ptarmigan or ptar-migan sign indicated use during the period May-August are included i n the following discussion. The areas may be c l a s s i -fied as diurnal covers (used by the male for daytime resting u n t i l the brood hatched), nesting sites and brood covers. The term "cover" i s used to indicate a space i n which ptarmigan carry out some essential a c t i v i t y . It may encompass several plant communities or only one, and i s of variable extent. Diurnal covers.—These covers receive constant use by male willow ptarmigan from the time the te r r i t o r i e s were estab-lished u n t i l the chicks hatched, except when courting or feed-ing a c t i v i t i e s were pursued elsewhere. Females also stayed i n this cover during inactive periods i n the preincubation stage of the breeding cycle. However, the diurnal cover i s primarily the male's apace, and probably i s selected by the cock. Three features were characteristic of diurnal covers of lagopus: (l) small size relative to the total size of the territory, (2) overhead concealment, and (3) outlook over a f a i r l y wide area. Typically, diurnal covers were isolated islands of t a l l shrubs surrounded by, or bordered on several 77 sides by, more open plant types. As has been mentioned, male ptarmigan seemed strongly attached to one (or occasionally two) such sites within the territory. Quite often the nucleus of the diurnal cover was formed by an isolated tree, large rock, "pingo" or frost mound, or stump. Examples of diurnal covers i n Chilkat Pass are shown in Figures 12-15. Nesting sites.—Data were obtained from 42 nesting sites at Chilkat Pass, one at A t l i n , B r i t i s h Columbia, and one at Eagle Creek, central Alaska. These data are presented i n f u l l i n Table V. An examination of the data suggests that the following features were essential: (l) some kind of permanent overhanging plant material, almost always woody plants; (2) an "open" plant community extending outward from one side of the nes:t. An open vegetation type i s defined here as one i n which the majority of plants are below the level of the eye of a mature ptarmigan (about one foot above the ground). Bryoids and graminoids were found most frequently i n the open type of vegetation. Regarding the f i r s t characteristic, the permanent nature of the overhanging plants should be emphasized. In May, when the hens choose nesting sites, shrubs were leafless, and the new year's growth of grass, sedge and forbs either had not begun or was very s l i g h t l y advanced. Thus, the only overhead protection available was provided by the branches of woody plants. One female willow ptarmigan (Eagle Creek, Alaska) nested directly under a small willow branch which had f a l l e n on the moss from t a l l shrubs to one side of the nest. Except this dead branch, the hen had no overhead concealment. 78 Cross-sectional view: SHRUBS J J I I I U I I SEDGE MARSH ROCK •"•-iiiiiinii "•••mt •»! lit III i II 11. imiinA O 5 10 20 SCALE (FEET) Top view: Structural diagram of Diurnal Cover: ml J 4' Figure 12. Diurnal cover number I (willow ptarmigan) 79 Figure 13. Diurnal cover number 2 (willow ptarmigan) 80 Cross-sectional view: a* i 1 0 5 10 20 1 i i i SCALE ( F E E T ) Top view: Structural diagram of Diurnal Cover: Figure 14. Diurnal cover number 3 (willow ptarmigan) 81 i i i i SCALE (FEET) Top view: Figure IS. Diurnal cover number 4 (willow ptarmigan) 82 Table V. Vegetation i n nesting sites of willow ptarmigan (Coverage percent i n each nest plot) West Gramin- „ J J t„ ^ ^„ w . n n < > „ Potent- Other Number oids B l T ° i d s P o r b s B i r e * W i l l G W t i l l a Shrubs ¥ 1 - 5 4 (8-10)* (12-18) (12-18) W 9 100 W 2 " 5 4 (6-10) wi ex c 10 50 20 15 5 W 1 _ 5 5 (8-18) (8-18) W9 60 1 0 15 5 10 W 2 ~55 ( 8 _ 1 0 ) 1 ° ( 6 _ i 2 ) (6-12) (6-12) 20 50 ¥ 3 - 5 5 10 10 (30-36) (30-36) 10 ¥ 4 - 5 5 20 15 60 (12-18) W r CC 80 20 ¥ 5 " 5 5 (6-8) (6-10) ¥ 6 - 5 5 10 40 10 40 (12-18) (12-18) (12-18) 15 85 W 7 _ 5 5 (6-10) (12-24) ¥ 8 - 5 5 5 15 ¥ 9 - 5 5 30 40 80 (24) 30 (8-16) 60 40 W10-55 ( 8 _ 1 0 ) (10-16) ¥ 1 1 " 5 5 1 0 2 0 Cl2-2*> (12-24) S p r u c e ¥ 1 - 5 6 20 10 ( J ® 3 6 ) ( 1 | 2 3 6 ) (180) *Wumbers i n parentheses indicate general range i n height (inches). 8 3 Table V—Continued Nest Gramin- „ . . „ m , ~. „ , . -, -, . Poten- Other Number ¥ 4 - 5 6 oids B r y ° i d s P o r * s B i r c t i W i l 1 ™ t i l l a Shrubs W9 qfi 2 5 f o 25/o 25% 2 5 f 0 w ^ - 5 b ( 8 - 1 2 ) ( 1 8 - 2 4 ) ( 1 8 - 2 4 ) ( 1 8 ) W 3 - 5 6 1 0 M O ° O / ^ 1 © ( 4 - 6 ) 1 U ( 1 2 - 2 4 ) 6 0 1 0 3 0 ( 6 - 8 ) ( 1 2 ) ( 1 2 ) w t . r / - 6 0 1 0 2 0 1 0 w : ? ~ : ) D ( 8 - 1 0 ) ( 1 2 - 2 4 ) ( 1 2 - 2 4 ) ( 1 2 - 2 4 ) ¥6-56 10 10 ¥7-56 2 0 ¥1-57 2 0 8 0 ( 1 2 - 1 8 ) 4 0 2 0 2 0 ( 1 8 - 3 6 ) ( 1 8 - 3 6 ) ( 1 8 ) ¥ 8 - 5 6 ( 1 0 _ 1 4 ) ( 1 2 - 1 8 ) u q R f i 2 0 3 0 4 0 1 0 "y-O© ( 8 - 1 2 ) ( 1 2 - 2 4 ) ( 1 2 - 2 4 ) ( 1 2 - 2 4 ) win R£ 1 5 o r 2 0 2 0 ¥ 1 0 - 5 6 ( 8 _ 1 2 ) 2 5 ( 8 - 1 8 ) ( 8 _ 1 8 ) w n sft 2 0 on 1 0 2 0 5 0 W H - 5 6 ( 8 _ 1 0 ) 2 0 ( 6 _ 1 2 ) ( 6 _ 2 4 ) ( 6 _ 2 4 ) W 1 2 - 5 6 ( 8 _ 1 2 ) ( 1 2 ) ¥ 1 5 " 5 6 ( 6 - 8 ) 25 ( 6 - 8 ) ¥ 1 4 ~ 5 6 2 0 ( 1 8 - 3 0 ) ( 1 8 - 3 0 ) ¥ 1 5-56 2 0 3 0 3 0 2 0 ¥ 1 6 - 5 6 (55 } 20 ( 1 2 - I 8 ) ( 1 2 - 1 8 ) 2 0 3 0 3 0 ( 1 2 - 3 6 ) ( 1 2 - 3 6 ) ( 1 2 - 2 4 ) 84 Table V—Continued Nest Gramin- ^  _ - ^.„ , ^ n ^ , , Poten- Other Number oids B r y ° l d s P o r b s B l r c h ¥ l l l o w t i l l a Shrubs WO C.T -rv/70 10$ >v//c ¥ 2 - 5 7 (6-10) (8-16) (8-16) M X 100 W 3 " 5 7 (10-16) 35 40 W4-57 20 5 (12-18) (12-18) W5-57 10 10 10 (1|236) (18^24) W6-57 10 (18-24) 1 0 (18-24) ¥ 7 " 5 7 1 5 2 0 0-2-18) 5 (12-18) ¥8-57 30 10 60 (12-24) (12-24) WO C-7 40 60 W 9 ~ 5 7 (36-48) (36-48) ¥10-57 ( 12-18) 1 0 (12-18) (12-18) ¥ 1 1 ~ 5 7 (8-16) 5 5 Eagle ¥1-56 15 45 Blue-A t l i n 30 5 25 berry 1958 30 (10) (36) (36) 5 ¥1-58 50 w ? Rfi PO 4 0 30 10 ¥ 2 5 8 2 0 (12-24) (12-24) (12) Total» 44 nests 50 (12-18) 40 (120-148 5 25 (36) (36) 20 25 (24) (18-24) 40 30 85 Table V shows that moss, graminoids or forbs covered the entire nesting site (the area within a 10-foot radius of the nest) i n only two instances. In those exceptional cases the nests were placed i n dense clusters of t a l l grass, whose dead, upright stems apparently provided adequate concealment. On the other hand, only one out of 44 nests was found i n an area completely dominated by shrubs. Thus, there seemed to be a definite necessity for both shrubby and open vegetation types i n nesting sites of willow ptarmigan. The median percentage of the plot surface covered by each vegetation type when present i n the nesting sites, and the range i n coverage, are given i n Table VI. The results of the analysis show the constancy.with which open and shrubby types were present i n nesting sites, and the great variation i n amount of each individual vegetation category i n the area around the nest. The tremendous variation may be due to the size of the plot i n relation to the nest. A l l of the stimuli necessary to release nesting behavior i n ptarmigan may be met within only a few square feet of area. Thus, a large area around the nest may have l i t t l e importance to the hen, although i t was included i n the survey plot. The dominance percentages i n Table VI include only those plots where the vegetation type was present. If the coverage per plot i s averaged for a l l plots, the following results are obtained: Graminoids . . . 29$ Salix 22$ Bryoids . . . . 11 Betula 20 Forbs 3 Potentilla (shrub) . 15 86 Table VI. Frequency and coverage of vegetation categories in nesting sites of willow ptarmigan Vegetation Category Frequency (percent of nests) Median Coverage When Present Range, Percent-age Graminoids 88 20 5-100 Bryoids 50 20 5- 50 Forbs 11 10 10- 30 Salix 68 30 5- 80 Betula 73 20 5- 60 Potentilla (shrub) . . 55 20 5- 80 Open type: Graminoids, Bryoids 98 4-0 10-100 Shrubs: Salix, Betula 93 60 20-100 A diagrammatic plot of a nesting site i s shown i n Figure 16, using the data l i s t e d above. Figure 17 i l l u s t r a t e s the general features of nesting sites of willow ptarmigan with photographs of a nest and the vegetation surrounding i t near Atlin, northern B r i t i s h Columbia. The majority of nests of lagopus were found on hummocky or s l i g h t l y sloping ground, i n mesic, well drained sit e s . Flat, low-lying land was often so wet that ground-nesting birds could not u t i l i z e i t , even though the vegetation may have been accept-able. Few nests were found on steeply sloping ground, perhaps because most of the work was done i n the f l a t bottom of Chilkat Pass. There i s no apparent i n t r i n s i c disadvantage to sloping land for nesting. Very often, nests were found along roadside 87 Vegetation mop of typicol nest site of willow ptarmigan, using averages of 44 nests. Structural diagram of typical nest site. Figuie 16. Average composition of vegetation in nesting sites of willow ptarmigan 88 Figure 1 7 . Nesting site of a willow ptarmigan near Atlin, British Columbia ( June IS, 1958). 89 ditches, streamhanks, gullies or isolated conifers i n the tundra. It may he that hens used microgeographic features such as those as means of relocating the nesting site, a l -though no proof of that point i s available. Brood covers.—It i s impossible to circumscribe brood covers as precisely as nesting sites for the simple reason that broods move. Therefore, the discussion w i l l center around data obtained from a few areas which received continu-al usage by many families of lagopus i n 1957 and 1958 at Chilkat Pass. Nest and brood covers were often indistinguishable as far as general character of the vegetation was concerned. The latter, i n fact, were often extensions of the same plant com-munities or stands which surrounded the nest. That does not mean that a brood was found near i t s hatching place, but that suitable nesting cover often was used by broods regardless of the place of origin of the chicks. The essential characteristics of brood covers, there-fore, were similar to nesting sites: they contained open areas interspersed with shrubs of moderate height. For older, strongly f l y i n g broods, t a l l , dense stands of willow or birch were useful as escape cover. The open areas used by chicks i often were more extensive than those i n nesting sites, as the chicks ran here and, there continually while feeding, and the whole family sometimes wandered several hundred yards i n the course of a few hours. The plants most frequent i n brood covers were Hedysarum alpinum, Astragalus alpinus, A. umbel-90 latum, Polygonum viviparum, Salix retioulata (a creeping willow), Arctostaphylos alpina, Dodecatheon frigidum, Anemone  parviflorum, Dryas drummondi, D. i n t e g r i f o l i a , Potentilla  fruticosa (a small shrub) and many mosses. Many of these plants were so small that even downy chicks could move through them with l i t t l e d i f f i c u l t y ; the larger ones occurred scatter-ingly throughout the cover. Perhaps the most e f f i c i e n t method of describing brood and nesting cover relationships i s to diagram a cross-section through typical l o c a l i t i e s u t i l i z e d by ptarmigan (Figures 18 and 19)• Although certain changes of scale were necessary, specific areas i n Chilkat Pass were used as models for the il l u s t r a t i o n s . Unoccupied Areas One of the best ways to discover the important factors governing the choice of places to l i v e i s to study areas which are not used, although f u l l y available to the species. In the present study, attention was given to plant associations within the general zone occupied by ptarmigan which were not u t i l i z e d , even though they may have been surrounded by occupied areas. The two most important types of unoccupied areas for willow ptarmigan were "herbmats" and "dry savannahs." "Herbmats" are luxuriant associations of plants i n alpine areas near timberline, where rich, deep s o i l , gentle to moderate slope, and a good supply of seepage water from higher areas, produce one of the most favorable habitats for plant RIVER Figure I8Q. River terrace topography used by willow ptarmigan, Chilkat Pass, British Columbia. Figure 18 b. Excellent brood cover for willow ptarmigan near a creek, Chilkat Pass, British Columbia. lichen opening Temporary pool broods lictvsn opening Figure 19a. Morginol brood cover in dry birch sites, Atlin ond Chilkat Pass, British Columbia. ro Fiim.M..llln.lii,,lll».iym,lllH„im1A & - " i Dense sedge ^^u^nn,,,,,,,,>,,,,TTX^ , ^•^•••••u,,^,,,,,,,,,, n U J W ^ p e n s e sedge broods Figure 19b. Wet tundra with restricted use by broods of willow ptarmigan, Chilkat Pass, British Columbia. 93-growth i n the alpine zone. A large number of flowering plants are always found i n such areas. Frequently, the herbmat i s interrupted by patched of t a l l willows or alders. Shrubs less than four feet i n height are rare i n this type of area. The herbmat i s a late biotope. Snow frequently accu-mulates to considerable depths around the patches of shrubs, and large amounts of water from melting snow prevent the s o i l from warming as rapidly as i n drier sites. Thus, i n late May and the f i r s t two weeks i n June, the ground remained nearly bare i n herbmat areas i n Chilkat Pass. Only small shoots of such plants as Petasites frigidus, Heracleum 1anaturn and Veratrum Eschscholtzii foreshadowed the great assemblage of plants to come later. In June the growth of perennials accelerated, and i n July herbmats were knee-deep (or even hip-deep) i n profusely blooming plants (Figure 20). In early August many species were s t i l l i n flower, but within a week or two the decline i n vigor of the plants became noticeable, and by mid-September only dead stems remained upright, to be beaten down by the wet snow of early f a l l . The changing seasonal aspect of herbmats i s shown i n Figure 21. Very few willow ptarmigan were found i n herbmats during the nesting and early brood seasons. Adults were present early i n May, and they probably fed throughout the winter on the buds of t a l l shrubs interspersed through the herbmat. From the end of May u n t i l late July, ptarmigan were singularly absent from herbmats. When the chicks were two-thirds the size of the adults, however, a few broods were found there. 94-Figure 20. Herbmat at Chilkat Pass, British Columbia (July, 1957). 96 I believe that the lack of usage i n June and early July was due to unfavorable characteristics of vegetation structure relating to nesting and brood-rearing requirements. In the sketch for late May and early June (Figure 20), there is a marked contrast between the dense cover provided by the thick stems of shrubs (which are usually from 6-10 feet i n height) and the barren ground of the herbmat. Neither of those biotopes provided the type of cover apparently necessary for nesting; yet this was the most important period for the selection of nest sites and for egg-deposition. The f i n a l sketch shows the density of the herbaceous plant cover i n herbmats i n July—and, i t w i l l be remembered, one of the essen-t i a l features of brood cover seemed to be the presence of areas covered with vegetation low enough to allow chicks to feed and travel readily. The second major unoccupied plant community was the bireh-willow-lichen savannah. Figure 22 i l l u s t r a t e s this vege-tation type. It occurred mainly on level tablelands through which rivers had cut, leaving behind a dry plateau. Vegetation that developed on such areas consisted of scattered clusters of Betula glandulosa and Salix spp. ( a l l shrubs 4—6 feet t a l l ) i n a matrix of lichens and tufted graminoids. The best examples of savannahs studied during the present research were at 3»000 feet at Ghilkat Pass near Kelsall Lake. It i s d i f f i c u l t to decide why dry savannah types were not u t i l i z e d by ptarmigan. Any or a l l of the following factors may have been operating: (1) scarcity of suitable nest sites (as i n herbmats, the Figure 22. "Sovonnoh" community and its relation to other vegetation types, Chilkat Pass, British Columbia. 98 "all-or-none" rule applied to the presence of shrubs); (2) scarcity of water, especially i n mid-summer; and (3) pau-ci t y of plant species of the kind eaten by ptarmigan. Of the six most common vascular, non-graminoid plants (Salix spp., Betula glandulosa, Salix reticulata, Veronica alpina, Artemisia sp., Aconiturn delphinifolium), only Salix reticulata was eaten commonly during the summer by adults and young. Two other types of uninhabited areas should be men-tioned b r i e f l y . One i s dense brush of any f l o r a l composition. Occasionally, such places were used as escape cover i f a ptar-migan was flushed, but even then the birds preferred to land i n small openings i n the shrubs. Probably the mechanical hindrance of bushes to walking, f l y i n g and vision was the basic reason for lack of use. The second kind of area i s the wet marsh—usually shrubless, but not necessarily so. If surface water i s present throughout the growing season, this i n i t s e l f may be enough to cause the area to be avoided by willow ptarmigan. In general terms, therefore, willow ptarmigan find most favorable conditions for breeding season a c t i v i t i e s i n mesic, mature communities of the lower alpine zone or low-arctic tundra. Rock Ptarmigan General Characteristics of the Zone Occupied If the zone of tundra occupied by willow ptarmigan can be characterized as a " t a l l shrub" zone, rock ptarmigan can be said to inhabit the adjacent "low shrub" zone. The most constant 99 feature of the habitat of mutus seen i n this study was the presence of shrubs between 1-3 feet i n height. Open vegeta-tive types, however, were more extensive than those found i n areas used by lagopus. lock ptarmigan were found higher on mountain slopes and further from the northern l i m i t of trees than willow ptarmigan. There seemed to be no overlap i n areas actually used by the two species during the early phases of breeding, including territory establishment, courtship, nest-ing and the early part of the brood season. It should be emphasized that the description of diurnal covers, nesting sites and brood covers of rock ptarmigan i n the following seetion applies only to the portion of the range of the species visited during the present investigation. Botanic evidence (Polunin, 1948) from extreme northern sections (such as Ellesmere Island) suggests that the species inhabits areas quite different from the more southerly regions. In upland tundra of subarctic h i l l s , such as at Eagle Creek, Alaska, i t was safe to predict that no rock ptarmigan would be found breeding among the t a l l willows of the valley bottoms, and that no willow ptarmigan would establish t e r r i t o r i e s or nest on adjacent slopes where t a l l shrubs did not occur. But whether the height of the woody plants was the important sepa-rating factor i s d i f f i c u l t to say at present. It may be that vegetation structure as described here i s not as important i n the habitat preference of rock ptarmigan as other factors as yet unrecognized. The two vertebrates most characteristic of the zone inhabited by mutus i n central Alaska were the caribou (Rangifer 100 arctieus) and the Lapland longspur (Calcareous lapponicus). Other birds seen frequently i n the same zone of tundra were the American golden plover (Pluvialis dominica), horned lark (Eremophila alpestris) and savannah sparrow (Passerculus  sandwichensis). Over vast areas i n Alaska and Canada, rock ptarmigan spend the summer on h i l l y ground. In southern B r i t i s h Columbia the minimum altitude at which mutus could be found was about 5,500 feet; i n the Canadian Arctic Archipelago they inhabit h i l l s only a few hundred feet above sea le v e l . Perhaps because of the topography, areas occupied by rock ptarmigan were rarely as moist as those frequented by lagopus. Occupied Areas Diurnal covers.—The sites chosen by male rock ptarmigan to rest and watch their territory during the daylight hours were similar to those used by willow ptarmigan i n one respect (wide outlook) and different i n the lack of overhead protection. The latt e r was one of the most marked differences i n vegetation used by the two species. Typically, male mutus sat on a small, sedge- and Dryas-covered knoll partway down the slope of a h i l l , often on or near exposed rocks. Here the cock, i n i t s white winter and breeding plumage, was very conspicuous. Some male rock ptarmigan roosted during the day on isolated, stunted spruce trees i n the tundra, or on high piles of gravel l e f t by past gold-mining activity. Bent (1912) summarizes the general features of diurnal covers of mutus i n the following way: 101 The male may often he seen s i t t i n g on his favorite perch on some prominent hummock where he has a good outlook, hut where he i s equally conspicuous; he apparently uses the same hummock regularly for i t is usually well decorated with dung and feathers. He was speaking particularly of courting male rock ptarmigan i n June on the Aleutian Islands. However, those words aptly describe what appears to he a general situation throughout the range of the species i n North America. Nesting sites.—Two characteristics appear from an examination of thirty nesting sites of rock ptarmigan i n the Eagle Greek area: (1) no nests were placed where the over-hanging shrubs were less than 10 inches or more than 3 feet i n height, and ( 2 ) open areas and shrubs were present i n every nesting s i t e . There i s a marked similarity i n the vegetation (as measured by height and coverage) of rock and willow ptarmigan nesting sites, although the breeding zone of the two species are separated a l t i t u d i n a l l y . This similarity i s brought out when the data for mutus nesting sites (Table VII) are compared to those i n Table VI. The frequency and median coverage when present of graminoids, bryoids and various woody plants are closely comparable. The proportions of Salix and Betula were reversed, but that was expected, as willows were more frequent i n the moist areas occupied by lagopus, and birches more abundant i n the well drained sites used by mutus. Heaths were more abundant i n the zone occupied by mutus. The average height of shrubs was about 17 inches i n the nesting sites of rock and willow ptarmigan (complete vegetation data for mutus 102 Table VII. frequency and coverage of vegetation categories i n nesting sites of rock ptarmigan Vegetation Category Frequency (percent of nests) Median Coverage When Present Range, Percent-age 80 30 10-80 43 25 10-50 Heaths and forbs . . . 47 20 5-50 50 20 5-50 83 40 5-80 Other shrubs 20 20 10-50 13 45 20-45 Open type: Graminoids, Bryoids, Heaths, Forbs, Rock 100 50 20-95 Shrubs: Salix, Betula and others . . . . 100 50 5-80 nesting sites are given i n Table VIII). This similarity i n vegetation i n nesting sites of the two species, mutus and lagopus, merits further discussion. The situation may be summarized by saying that both species chose nearly the same type of vegetation i n which to nest despite the fact that mutus occupied areas with fewer shrubs and (generally) lower shrubs than lagopus. Thus, i t appears that lagopus selected the most open areas within i t s zone i n which shrubs can be found: such shrubs usually were of small to moderate size i n relation to most of those i n the v i c i n i t y of the nest. Rock ptarmigan, on the other hand, bred i n areas 1 0 3 Table VIII. Vegetation i n nesting sites of rock ptarmigan (Coverage percent i n each nest plot) Nest Gramin- Heath Birch Willow ^ r u c e Rock, Number oids J Alder bare R l - 5 4 1 5 % 3 0 % 5% ( 1 2 - 3 6 ) * ( 1 2 - 3 6 ) P , r.. 2 5 OR 2 0 3 0 R 2 ~ 5 4 ( 4 _ 8 ) 2 5 ( 6 - 1 2 ) ( 6 - 1 2 ) R3-5* * ° ( 1 2 - 3 6 ) 1 0 ( 1 2 - 3 6 ) R ^ ( 6 - 1 0 ) ( 1 8 ) vii RR 2 0 o n 5 0 1 0 R 1 _ 5 5 ( 6 - 8 ) 2 0 ( 8 - 1 4 ) ( 8 - 1 4 ) p o RR 3 5 -| n 3 0 2 5 ( 1 0 - 1 5 ) ( 1 2 - 2 4 ) ( 1 2 - 2 4 ) R 5 " 5 5 ( 8 - 1 0 ) 2 0 * ° ( 1 0 ) R 4 - 5 5 2 0 1 0 3 0 4 0 ( 1 2 - 2 4 ) ( 1 2 - 2 4 ) R 5 " 5 5 ( 6 - 8 ) 5 0 ( 1 2 - 2 4 ) ( 1 2 - 2 4 ) R 6 - 5 5 5 0 5 0 ( 8 - 1 2 ) R7-55 40 ,to\ 20 R 8 - 5 5 2 5 R9-55 3 0 3 0 ( 1 2 ) 3 5 3 0 1 0 ( 1 2 - 1 8 ) ( 1 2 - 1 8 ) ( 1 2 - 6 0 ) 4 0 ( 1 2 - 2 4 ) pin RR 5 0 50 R 1°-55 ( 6 _ 1 2 ) (12-24) R l l - 5 5 3 5 10 3 5 20 R l 9 RR 4 1 0 50 R12-55 ( 6 _ Q ) ( 1 2 ) ( 6 - 1 2 ) •Number i n parentheses indicates general range i n height (inches). 104 Table VIII—Continued Nest Gramin- T > „ „ „ H J „ t i Q„4 - v , TJ^^^V , w - i - n ™ , Spruce Rock, •KT -u Bryoids Heatn Bircn willow T } „ „ ~ Number oids J Alder Bare 20/o 30$ 50$ (4-10) (6-10) (24-48) R14-55 80 20 (6-8) (10) R15-55 (^g) 30 20 10 30 20 80 (10) (10) R16-55 Rl-56 10 20 50 20 (8-14) (36-60) R7-56 20 10 R8-56 10 40 70 (6-12) 50 (12-24) R9-56 10 50 Rl-57 10 10 10 Total = 30 Nests 70 (10) 45 R 2"56 (8-15) 2 0 (10-15) R4-56 60 20 20 R5-56 15 ( 1 ^ 3 6 ) 45 p f i c c 30 30 10 Rb-5b ( 8_ 1 0) (8-20) (8-20) 30 105 where there were few patches of shrubs present, and females nested under the t a l l e s t woody vegetation available i n spring. This tendency on the part of female rock ptarmigan became i n -creasingly evident as the frequency of occurrence of shrubs decreased. In the upper parts of the zone used by mutus for nesting, extensive areas were covered with sedges, grasses, low forbs, mosses, lichens and Dryas. Shrubs were confined to the rims of s o l i f l u c t i o n ( s o i l creep) ridges (Pig. 23). The only nests found at this altitude at Eagle Greek had been built i n such thin lines of shrubs. In one case, a small valley uninhabited i n 1956 contained one old nest on the edge of a s o l i f l u c t i o n ridge; i n 1957 a female mutus nested under the low birch shrubs only 10 feet from the old nest. One criticism of the data on height and coverage of vegetation i n nesting sites i s that they present a composite picture of conditions which prevailed over a plot approxi-mately 78 square feet in area, with the nest as i t s center. The preference of the hen may have applied only to a much smaller area; consequently, the method may not be sensitive enough to detect differences i n choice of nesting sites between mutus and lagopus. Due to the h i l l y nature of the terrain at Eagle Creek, the direction of the slope played a part i n the placement of nests of rock ptarmigan. Table IX shows how the actual dis-tribution of thirty nests found at Eagle Creek compares with the theoretic distribution i f i t was assumed that there was no preference with regard to the direction of the slope. 106 Figure 23. Solifluction ridge nesting site of rock ptormigan, Eagle Creek, Alaska. 107 Table IX. Distribution of 30 nests of rock ptarmigan at Eagle Creek, Alaska, with respect to slope Slope Direction Percentage .©.£-' Total Area Theoretical Nest Distribution Actual Distribution North-facing 27 8 17 South-facing 19 6 2 East-facing 15 4.5 2 West-facing 24 7 5 Level 15 4.5 4 More nests were found on north-facing slopes than would be expected from the amount of area covered by such slopes i n relation to the total area studied. Probably snow distr i b u -tion was responsible for the unexpectedly large number of nests on north-facing slopes. More snow accumulated on south-and west-facing slopes, due to the direction of prevailing wind direction i n winter. The pile-up of snow on south-facing and west-facing slopes more than balanced the faster rate of melt on those slopes i n spring. The ptarmigan, therefore, were able to nest earlier on north-facing slopes; the result was that the majority of the small population of mutus estab-lished themselves on these slopes. It is also possible that bare knolls were attractive to male rock ptarmigan when they began to establish t e r r i t o r i e s i n spring. Brood covers.—Broods of rock ptarmigan usually spent the f i r s t few weeks of l i f e i n vegetation only s l i g h t l y d i f -ferent from the nesting s i t e . Broods were found commonly at 108 the headwaters of small streams where continual seepage pro-duced a relatively luxuriant, although low, vegetation of graminoids and flowering perennials interspersed with small clusters of low willows, birch and blueberry. A few broods remained near their nesting sites on lower slopes throughout the summer. A sample plot i n a typical brood cover appeared as i n Figure 24. The composition of the vegetation i n the plot, together with the percentage of the total area dominated by each species, was as follows: percent l e t u l a glandulosa . . . . 30 Vaccinium uliginosum . . . 20 lupinus arcticus 5 Vaccinium vitis-idaea . . 5 Salix pseudopolaris . . . 10 Dryas i n t e g r i f o l i a . . . . 10 Empetrum nigrum 5 Lichen (unidentified) . . 10 Grasses (unidentified) . . 5 Later i n the year (beginning about August 1, 1957), broods began to frequent the f l a t areas and moist depressions on h i l l t o p s , where sedges predominated (Pig. 25). Rock ptar-migan broods at Eagle Greek did not u t i l i z e ridgetops where rock fragments l i t t e r the surface of the ground, and where the only vegetation i s a thin carpet of Dryas, scattered sedges, and lichens. In Figure 26, pairs of plots show the contrast between u t i l i z e d and unutilized areas with respect to broods and nests. 109 Figure 24. Structural diagram of a typical brood cover of rock ptarmigan. 1 1 0 Figure 25. Brood cover of rock ptarmigan near Atlin, British Columbia ( June 9, 1958) ( lo) (lb) July 8, 1958- Near Palmer, Alaska, Altitude 3300' July 9, 1958- Near Palmer, Alaska, Altitude 3100'-same s. w. slope - L. mutus hen and chicks slope as in ( la) . Unutilized . July 21, 1958 • Eagle Creek, Altitude 2900' - north slope July 21, 1958- Eagle Creek, Altitude ond slope same os(2o) L mutus habitat Not L. mutus habitat Figure 26. Paired vegetation diagrams of utilized and nearby unutilized areas in zone inhabited by rock ptarmigan broods ( 3 a ) (3b) July 24, 1958 • Eogle Creek, Altitude 2850'-west slope moist • L. mutus occupied. (4a) July 26, 1958 • Eagle Creek, Altitude 4200' moist, level L. mutus broods occosionol. July 25, 1958 • Eogle Creek, Altitude 3800'-east slope stony barren • Unoccupied. (4b) July 26, 1958 • Same place as ( 4 a ) , dry site Unoccupied. Figure 26. Continued. (5a) (5b) July 25, 1958 • Eagle Creek, Altitude 3650' north slope, moist. Hen and brood of L. mutus 2' July 25,1958- Same slope as (5a). Altitude 3750' Unoccupied. r~> H Figure 26. Continued. 114 Figure 26—Continued L i s t of plants occurring i n plots Percent Coverage (la) Salix (creeping).. 25 Salix (shrub) 20 Moss 10 Phyllodoce. Empetrum 25 Valeriana 5 (2a) Salix (shrub) .... 5 Betula (shrub) ... 30 Ledum. 10 Vaccinium uliginosum 10 V. vitis-idaea ... 15 Graminoids 10 Moss 10 Polygonum, Peta-sites, Empetrum 10 (3a) Be tula 30 Salix 5 Ledum 35 Vaccinium uliginosum 10 Moss 10 Sedge 10 Petasites, Rubus Trace (4a) Salix (creeping), Betula (pros-trate) 5 Saxifraga nivalis 5 Graminoids 50 Bare . 10 Moss, Dryas 10 Polygonum 10 S t e l l a r i a 5 Cruciferae (unid.) 5 (5a) Salix (shrub) .... 10 Salix reticulata.. 10 Graminoids 30 Dryas 20 Dodecatheon 5 Equisetum 5 Saxifraga hircuius 10 Pedicularis, Polygonum Trace Aconitum ........ Trace Other herbs 5 Percent Coverage (lb) Salix (shrub) 90 Veratrum 5 Valeriana 5 Understory: Empetrum, Grass, Artemisia, Vaccinium (2b) Salix (shrub) 80 Be tula 10 Spiraea 10 Understory: Aconitum, Petasites frigidus, Ledum, Moss, Vaccin-ium uliginosum, Graminoids (3b) Rock or bare 65 Loiseleuria 10 Cassiope 5 Dryas 5 Artemisia 5 Salix pseudopolaris Trace Campanula Trace V. vitis-idaea Trace Empetrum Trace (4b) Salix pseudopolaris.. 15 V. vitis-idaea 10 Ledum 5 Loiseleuria 10 Cassiope 5 Moss 20 Bare 10 Sedge 15 Dryas 5 Lichen, Pedicularis.. 5 (5b) Rock or bare .... — . 15 Saxifraga l y a l l i i ... 30 Oxyria digyna 30 Sedum rosea 5 Claytonia 5 Ranunculus 5 Grass, moss 10 Artemisia, Polemonium Eriogonum Trace 115 Unoccupied Areas There i s no necessity for describing i n detail the types of areas not used by rock ptarmigan, as they were the same kinds of places avoided by willow ptarmigan at lower a l t i -tudes. Very dry sites, such as knolls, h i l l t o p s , and steep south-facing slopes; very wet areas; areas of dense shrubs; and plant communities without woody plants (except for some brood covers, as described above) received l i t t l e or no usage by breeding rock ptarmigan. White-tailed Ptarmigan General Characteristics of the Zone Occupied Above the dark coniferous forests of the mountains of northern B r i t i s h Columbia, above the green and flower-strewn alpine meadows, and beyond the narrow zone of low shrubs, l i e s an area of jumbled rock slides, boulder fiel d s and wasting gla-ciers. Despite i t s barren appearance, this i s the summer home of mountains goats (Oreamnos), pika (Ochotona), rosy finches (Leucosticte) and white-tailed ptarmigan. At the southern l i m i t of their range (Colorado and per-haps northern New Mexico), white-tailed ptarmigan l i v e at a l t i -tudes of 12,000 feet or higher; i n southern B r i t i s h Columbia, suitable habitat occurs at 5,500 feet on the coast, 7,500 feet in the interior. Further north the altitude of occupied areas slowly decreases, u n t i l , at Mount McKinley National Park i n central Alaska, leucurus i s found at 000-5,000 feet. The change i n altitude (about 8,000 feet) from north to south i s approximately the same as for willow ptarmigan (from 7,200 feet 116 to sea le v e l ) . In the central and northern parts of white-tailed ptar-migan range, the zone occupied by leucurus i s hounded at i t s lower edge where vegetation begins to cover the ground com-pletely, or nearly so, and at i t s upper edge by the unvegetated zone. The change from a continuous to a discontinuous vegeta-tion often coincides with the appearance of c l i f f s , ledges and talus slopes, while the disappearance of plants at the upper edge of the alpine area i s controlled by climatic as well as physiographic factors. Occupied Areas The f i d e l i t y of white-tailed ptarmigan to a particular kind of tundra habitat was remarkable. Prom May to September, the writer found i t possible to t e l l exactly where leucurus would or would not be found, no matter whether the mountains studied were i n southern B r i t i s h Columbia or central Alaska. This constant choice of the same milieu made i t possible to de-scribe the habitat of white-tailed ptarmigan with some accuracy, even though fewer observations were made on that species than either of the other two. The descriptions which follow apply mainly to diurnal and brood covers, as only two nesting sites were found over the entire period of study. Data from twelve nesting sites located i n Glacier National Park by other obser-vers are included. Having once stated that the zone occupied by white-tailed ptarmigan i s , for a l l practical purposes, shrubless, 117 I believe that further descriptions of vegetation should follow a discussion of the physical features of the habitat of this species. For i t i s the ruggedness of the slope, the rockiness of the ground, the obvious impact of weathering and the i n f l u -ences of s o i l moisture and precipitation, which most strongly impress themselves on the observer traveling through white-tailed ptarmigan country. Further, i t i s believed that the visual cues which cause individual white-tailed ptarmigan to select certain sites for breeding, after the wanderings of the winter period, are physiognomic cues, and that white-tailed ptarmigan are demonstrably adapted to the physical "structure" of their environment. One of the most important prerequisites for areas used by leucurus was relative s t a b i l i t y of the substrate. To one accustomed to the lowlands, i t i s d i f f i c u l t to imagine that this factor could be of widespread importance. However, a t r i p to the Arctic, or to the alpine zone of a mountain, would quickly change that viewpoint. The advance and recession of glaciers, the movement of water, the action of subsurface ice (congeliturbation), the cracking of rock by physical forces of weathering, the tumbling of snow and rocks i n avalanches and the predominating influence of slope steepness combine to create an environment i n which fundamental changes with f a r -reaching effects occur rapidly. In general, relative s t a b i l i t y (enough to allow a reasonable variety of plants to grow) i s achieved i n two types of places: (l) where the slope i s gentle enough so that gravity i s ineffective (glacial cirques, near 118 old moraines, on some ridgetops and around g l a c i a l potholes), or (2) under conditions wherein rock strata break up into large, angular boulders which, even on steep slopes, lodge together so as to create a "stable" rock slide, where pockets of s o i l develop, accompanied by patches of vegetation. Figure 27 shows such a stabilized talus slope. There i s often a definite relationship between kind of rock and s u i t a b i l i t y of mountains for animal inhabitation. After working i n the v i c i n i t y of Glacier Bay, Alaska (a short distance from Chilkat Pass, B r i t i s h Columbia, where ptarmigan studies were carried out), Cooper (1923) stated that The a r g i l l i t e s and slates furnish with l i t t l e delay a favorable substratum for the pioneer plants, but con-tinued weathering aided by gravity destroys many of the early arrivals, and on very steep slopes notably retards the progress of succession by constantly producing fresh surfaces. Where the slope i s reasonably gentle, however, this type of bedrock affords the best physical conditions of any for the rapid establishment of vegeta-tion. The diorites, quickly breaking into large blocks and slabs, are decidedly less favorable. The limestone and marble surfaces are worst of a l l , retaining their smoothly glaciated contours indefinitely, weathering by solution rather than disintegration. Although i t i s not yet possible to c l a s s i f y a l l rocks as to their potentiality for producing conditions suitable for leucurus, i t i s quite certain that mountains of marble and limestone would be less l i k e l y to furnish suitable habitat than almost any other type of rock i f weathering occurred as de-scribed by Cooper. Some mountains i n Jasper National Park, Alberta, appear to be unfavorable to ptarmigan for that reason. Even though diorites might take longer to produce s o i l (and therefore vegetation), i t i s l i k e l y that mountains of such Figure 27. Rockslide utilized by white-tailed ptarmigan near Boulder Creek, Atlin, British Columbia (August 24, 1957). 120 material would "be more suitable for ptarmigan than the rapidly crumbling shales and a r g i l l i t e s by virtue of the greater sta-b i l i t y of steep slopes of the former. A second important factor was snow—its quantity, dis-tribution and rate of melting. There i s a point of balance between too much and too l i t t l e snow as far as leucurus i s con-cerned. No quantitative data are available as to actual depths of snow at which the point of balance i s reached; i t would vary greatly from one area to another. Too l i t t l e snow, and the habitat receives no protection from winter winds, and receives water from melting snow for only a brief time i n summer. Too much snow, on the other hand, prevents many plants from germi-nating, flowering or f r u i t i n g . In either ease, the lack of plants means a lack of animals. Third, a factor more intimately related to ptarmigan themselves was the size of rocks or boulders i n the habitat. It appears from my observations that white-tailed ptarmigan chicks are peculiarly adapted to u t i l i z i n g crevices i n rocks for escape cover. Their natal down and juvenile plumage are much grayer than those of the other two species; their colora-tion i s decidedly cryptic i n the lichen-covered rocky habitat i n which the broods are found. White-tailed ptarmigan of a l l ages sought rough microterrain of various sorts (ledges, c l i f f s , rock slides, boulder fields) to lessen the force of the winds which blow almost ceaselessly at high altitudes. Therefore, niches (in the physical sense) of a certain size must be present i n the habitat; these crevices are produced by rocks 121 of at least one foot i n diameter. Given two slopes at the same altitude and containing the same plant species, with one possessing boulders and out-thrust ledges, the other smooth and with well-developed vegetation, only the one with rough mieroterrain would be occupied by white-tailed ptarmigan. Sta b i l i t y of substrate, proper degree of snow cover and large size of rocks, therefore, are three features of the environment which apparently were correlated with the presence of white-tailed ptarmigan. There are three common situations where these features are found, namely, ledge and rock slide combinations, f e l l - f i e l d s and g l a c i a l cirques. Each situation i s described b r i e f l y here. A favorite dwelling place of leucurus i n summer was the ledge and rock slide combination often found midway down the slopes of mountains i n northern B r i t i s h Columbia and southern Yukon. Characteristically, the ledges are dissected by ravines and small water courses, and are composed of a number of narrow shelves. The shelves collect s o i l and trap moisture, and pro-vide excellent sites for the growth of many alpine plants. Rock slides often result from the weathering of the ledges, and ptarmigan often use sueh screes throughout the year i f they are free of snow i n winter. Figure 28 i l l u s t r a t e s the ledge and rockslide type of habitat. Two nests of white-tailed ptarmigan were found at Chilkat Pass on the narrow shelves of broken c l i f f - f a c e s . The same type of site was used by white-tailed ptarmigan nesting i n Glacier National Park, Montana (Evans and Fisher, 1958). Twelve nests were found during that study; eight of these were located 122 Figure 28. Ledge and rocksiide habitat of white-tailed ptarmigan. Top: Chilkat Pass, British Columbia. July 31, 1957. Bottom: Columbia Icefields area, Banff National Park, Alberta, May 26,1958. 123 pa r t i a l l y or wholly beneath overhanging ledges, two were i n the open beside large boulders and two were on open ground without overhanging ledges or nearby boulders. F e l l - f i e l d i s a term used for rocky, windswept, boulder-strewn plateaus or level ridgetops i n alpine areas, usually dominated by lichen-graminoid communities with smaller amounts of perennial forbs. If f e l l - f i e l d s contained large boulders, out-thrust ledges and a sufficient range of moisture conditions to assure a varied vegetation, they were occupied frequently by leucurus i n the areas studied (Figure 29). Glacial cirques are formed by the erosive force of alpine glaciers at or near the top of mountains. They are often shaped li k e a cup broken i n half v e r t i c a l l y . Where these cirques were blocked off at their outer (lower) end by land-slides so that the resulting depression f i l l e d with s o i l and trapped moisture, ideal conditions prevailed for leucurus. Many broods, especially, were found i n such areas. The vegetative component of white-tailed ptarmigan habitat scarcely ever attained a development sufficient to provide shelter for an animal the size of ptarmigan. Except for a few stems of forbs and graminoids, most plants were less than 6 inches i n height. In many places only open "communi-ties" were present, with individual plants separated by rocks or bare s o i l ; closed or continuous vegetation was rare. White-tailed ptarmigan were seen many times i n areas where vegetation covered only 5-20 percent of the ground. Although lichens, mosses, fungi and graminoids formed the bulk of the f l o r a i n areas used by leucurus, such plants as Saxifraga spp., Oxyria 124 Figure 29 . Fell-field utilized by white-tailed ptarmigan, mile 97 Haines Road, British Columbia (July 3 , 1958). 125 digyna, Oxytropis spp., Cardamine b e l l i d i f o l i a , Parrya nudi-caulis, Potentilla spp., Arctostaphylos alpina, Ranunculus spp., Dryas i n t e g r i f o l i a , D. octopetala, Artemisia sp., Silene  acaulis, S t e l l a r i a spp., Sedum spp. and Polygonum viviparum were common. Unoccupied Areas Besides sites characterized hy extreme dryness or by shifting substrate, one other unutilized habitat should be de-scribed. This i s the Phyllodoce-Oassiope-luetkea association, typical of moist plateaus i n the lower portion of the zone u t i l i z e d by leucurus. Phyllodoce glanduliflora, P. empetri-formis, and Cassiope tetragona are woody Ericaceae of heath-like form. They form solid mats from 3-8 inches i n height (Figure 30) on certain well watered slopes or plains receiving a re l a t i v e l y large amount of snow. The fru i t i n g capsules which form i n July and persist u n t i l the following spring are used occasionally as food by white-tailed ptarmigan. Luetkea  pectinata i s a woody plant related to meadowsweet (Spiraea), whose leaves rarely rise more than an inch or two above the ground, although the stalk of white flowers may be 6 or 8 inches t a l l . These four species, i n various combinations, often form such dense stands that most other species cannot gain a foothold i n the association. I believe that i t is the d i f f i c u l t y young ptarmigan would have i n travelling through the dense, s t i f f -stemmed vegetation, the lack of exposed rock for shelter and the relative monotony of the vegetation which made such areas 126 Figure 3 0 . Luetkeo - Phyllodoce - Cossiope community near Palmer, Alaska Uuly 9, 1958). 1 2 7 unsuitable for leucurus. A few nests have been found i n patches of vegetation similar to the association just described, by investigators i n the United States (Jewett et a l . , 1 9 5 3 ) . However, the descriptions of the nesting site usually indicate that boulders or rocky areas were present. Summary of the Gharacteristics of the  Habitat of Ptarmigan A l i s t of characteristics of occupied and unoccupied areas has been compiled from the foregoing descriptions of the summer habitats of each species of ptarmigan. Willow Ptarmigan This species breeds from the fringe of forests to the end of the zone of t a l l shrubs i n alpine and low-arctic areas. The most suitable vegetation types are usually mesic, mature communities. Occupied areas. ( 1 ) Shrubs, usually Salix or Betula, mostly over 3 feet i n height. ( 2 ) Shrubs in clusters, interspersed among areas covered by graminoids, bryoids or perennial forbs. ( 3 ) Intermediate layer of grass, sedge, heaths and forbs well developed and extending under the t a l l shrubs. ( 4 ) Open areas present, with vegetation less than 1 2 inches i n height. ( 5 ) Relatively large number of plant species present. 128 Unoccupied areas. (1) Dry "savannah" community of t a l l shrubs, lichens and graminoids. (2) Alpine herbmats. (3) Marshy areas with permanent surface water. (4) Dense, continuous shrubbery. Rock Ptarmigan This ptarmigan inhabits xeric to mesic plant commu-nities of alpine and arctic regions a l t i t u d i n a l l y or l a t i t u d i -nally beyond the zone of t a l l shrubs, and further from timber-line than lagopus. Occupied areas. (1) Small shrubs between 1-3 feet t a l l . (2) Clusters of shrubs interspersed among open types of vegetation. (3) Variety of plant species, especially berry-bearing Ericaceae. Unoccupied areas. (1) Shrubless, graminoid covered meadows (except for use by some broods i n late summer). (2) Dense, unbroken shrubbery. (3) Excessively wet or dry areas. White-tailed Ptarmigan This species dwells exclusively i n high alpine areas, characterized by dynamic physiography and poorly developed vegetation. 129 Occupied areas. (1) Shrubs lacking or very rare. (2) Stable substrate. (3) lock fragments or boulders present, usually larger than 1 foot i n diameter or i n several layers so that crevices are abundant. (4-) Ledges, c l i f f s or outeroppings with narrow, vegetated shelves. (5) Variety of plant species, although vegetation need not cover more than 20 percent of the ground. Unoccupied areas. (1) Phyllodoce-Cassiope-Luetkea community. (2) Extensive areas of closed (complete) vegetation. (3) Gravelly (as opposed to rocky) slides or barrens. (4-) Phenologically late habitats and very dry sites. 130 ECOLOGIC AND GEOGRAPHIC DISTRIBUTION The pattern of the distribution of ptarmigan must be examined before various factors affecting i t are discussed. The approximate ranges of Lagopus spp. i n North America are shown i n Figures 31-33. Each species inhabits certain regions alone; rock ptarmigan i n the northern Canadian Arctic Archi-pelago (as well as Greenland and Iceland), willow ptarmigan in coastal areas along the Bering Sea i n Alaska and bordering the southern fringe of tundra i n central Canada, and white-tailed ptarmigan i n western United States. However, lagopus and mutus occur together over a large part of Alaska and Canada, and a l l three species are found i n the northwestern Cordillera of B r i t i s h Columbia, Yukon and southcentral Alaska (Figure 34). Thus, i t could be said that both allopatric and sympatric popu-lations of each species exist. A closer examination of the region of alleged sympatry shows that each ptarmigan actually occupies a discreet area which may or may not interdigitate with areas occupied by the other species. The basic reason for this is probably that alpine-arctic tundras do not afford a chance for a v e r t i c a l "layering" of closely related species within one plant commu-nity, as, for example, deciduous woodlands might. This i s especially true for large birds such as ptarmigan. Therefore, one alternative, i f each species i s to occupy a separate niche, i s for a horizontal or al t i t u d i n a l separation to develop. 131 mm— Approximate boundary of the range of L. leucurus. Darkened areas indicate summer records. ii TO ' 1 •-—/_ - * i*V\ V I — ( lsi--~L~<:-0 A-.V~.-L Figure 31. Approximate range of white-tailed ptarmigan. Figure 32. Approximate range of willow ptarmigan. Figure 33. Approximate range of rock ptarmigan. 134-Figure 3 4 . Overlap of the geographic ranges of three ptarmigan. 135 Seasonal changes i n the spatial relationships between species of ptarmigan also merit further discussion. In the period between October and early April the various ptarmigan may occur together (in the same flocks or i n the same restricted l o c a l i t y which may be the breeding ground of only one species) or they may be more widely separated than i n the breeding sea-son due to migration. In the latte r case the species are separated effectively throughout the year. In the former instance, winter populations of ptarmigan may occupy the same area and eat the same foods at the same time of day. This re-sults from the great r e s t r i c t i o n i n potential sources of food and the very short daily feeding period. They may roost i n the same bushes or i n the same soft patch of snow, and may hide i n the same way from the same enemies. Therefore, i n the func-tional sense, the distinctness of each species i s blurred, and they appear to be essentially the same organism with similar interactions with their environment. Ih spring the picture i s changed completely. The spe-cies move to their separate breeding areas and have practically no contact with each other through the courtship, nesting and, often, brood rearing periods. In the brood season the habitats used may overlap slightly; families of willow ptarmigan may occupy the same places used for nesting by rock ptarmigan, and habitats used by broods and single males of leucurus and mutus may be similar. 136 Factors Affecting Ecologic Distribution If the local area occupied by a population coincides consistently with one element of the environment, while popu-lations of related species occupy contiguous areas not charac-terized by that element, then i t i s at least circumstantial evidence that this factor i s somehow necessary to one form and not to the others. One of the f i r s t steps taken i n the present study to determine the factors affecting local ptarmigan dis-tribution was to seek out such "common denominators." It appeared that the local distribution of each species of ptar-migan during the breeding season coincided with vegetation of distinctive physiognomy. The factual basis for that conclusion was l a i d i n the previous section, wherein a distinctive habitat was described for each species using vegetation structure as the most important criter i o n . It i s necessary now to demon-strate the f i d e l i t y of ptarmigan to their associated vegetation communities over a wide range of conditions. To accomplish that objective a series of sketches was prepared, each designed to show the main features of the alpine zone i n the areas vi s i t e d . The sketches may be divided into those representing areas with three, two, or only one species of ptarmigan. A brief resume of each figure follows: Figure 35. Chilkat Pass, mile 75 Haines Road, B r i t i s h Columbia. Three species present, but mutus relatively rare. The f l a t , marshy areas near the river provide excellent timber-shrub habitats for willow ptarmigan. On the 137 west side of the road the mountain slopes are mostly-smooth, while small-particled, gravelly, poorly-vegetated slopes above 4,300 feet. The zone of t a l l shrubs and herbmat gives way abruptly to shrubless, grassy area at about 4,000 feet, so that leucurus and mutus are uncommon, particularly the l a t t e r . To the east of the road, i n the Kelsall Mountain area, ledges and rockslides provide better habitat for leucurus. In restricted areas, where f o o t h i l l s or low ridges are interposed between the steep slopes and the f l a t s , mutus populations may be found. Figure 36. Ghilkat Pass, mile 65 Haines Road. Three species. A small, rocky h i l l rises out of the f l a t s and pro-vides one of the better areas for mutus i n the Pass. The west-facing slope contains many out-'thrust ledges, usually skirted by patches of small shrubs; this slope i s inhabited by rock ptarmigan. On the crest of the h i l l , however, the surface i s more rocky and shrubs are absent. On the top of the h i l l there i s a steep-sided hollow which remains f i l l e d with snow and/or water throughout the summer. The h i l l t o p area i s occupied by leucurus. Figure 37. Chilkat Pass, mile 77 Haines Road. More detailed view of an area where leucurus and mutus populations are not separated a l t i t u d i n a l l y . L. mutus occupies l o c a l i t i e s Figure 3 5 . Mile 7 5 Hoines Rood, Chilkot Poss, British Columbio. L . leucurus Rocky slide, ledges, cliffs, steep, dry slopes; lichens, sedge, Voccinium, xeric herbs. . 5000' N Moist, marshy areas with moss, sedge; toll Salix i to 10 feet in height. L. mutus Rocky hilltop, with steep, dry ledges and escarp-ments. No shrubs over one foot in height. i i i I L.leucurus unoccupied zone Sloping, smooth; SoM-lichen-heath. No shrubs over one foot; smoll rocks on scree slopes at base of mountains. 4500 ,3800' Birch and Willow shrubs one - three feet on favorable oreas; moderate slope, some exposed rock. .3200 L.logopus Figure 36. Area I mile east of mile 65 Haines Road, Chilkat Pass. 140 Figure 3 7 . Interspersion of rock and white-tailed ptarmigan breeding habitat, Chilkat Pass, British Columbia. 141 where moderate slopes allow small shrubs to gain a foothold. That type of area occurs both above and below the steep, rock-strewn slopes and ledges which provide homes for leucurus. (The mutus habitat below the leucurus-inhabited areas i s not shown i n this sketch.) Figure 38. Coastal side of Coast Range, mile 52 Haines Road. White-tailed ptarmigan were present i n areas above those depicted i n the sketch. The abrupt transition from extremely dense, t a l l alders to shrubless commu-nities pinches out the zones of mutus and lagopus to a great extent. Thick mats of Luetke.a, Phyllodoce and Cassiope are found above 3»500 feet, wherever the topography i s r o l l i n g rather than rugged. Such habitats were not used by leucurus. Figure 39-Talkeetna Mountains, southcentral Alaska. Alpine areas immediately above timberline are moist and r i c h l y -clothed with alder and herbmat communities. Three species of ptarmigan are present: lagopus i s r e s t r i c -ted to willow-covered streambanks and a few shrubby h i l l s i d e s ; mutus populations are scattered due to the narrow, discontinuous nature of the low shrub zone; leucurus i s found i n moderate numbers on nearly a l l mountains i n the zone of ledges and rockslides. As at the coastal end of Chilkat Pass, the Phyllodoce-Luetkea-Cassiope community i s common on moist, rocky, 142 Figure 36. Coastal side of Coast Range, northern British Columbia. Figure 39. Little Susitno River orea, Talkeetna Mountains, Alaska. 144 level or r o l l i n g areas above timberline; such places support few or no ptarmigan. Figure 40. Boulder Greek and v i c i n i t y , A t l i n , B r i t i s h Columbia. This i s actually a composite sketch, integrating topo-graphical and vegetational features of Wright Creek and Boulder Creek areas. The portion to the l e f t of the creek represents the Boulder Creek area, where mutus populations are absent or very low. Rock ptar-migan were common above Wright Creek, however, and the features of areas occupied by that species are shown to the right of the creek. The l o c a l i t y east of A t l i n i s less rugged and drier than the coastal areas shown i n the preceding sketches. Figure 41. Nine-mile Mountain, Hazelton, central B r i t i s h Columbia. The zone of mutus i s narrow, so that on steep slopes i t i s almost completely lacking. However, the south ridge of the mountain levels off just above the last stunted spruce and f i r stands, and mutus inhabits the hi l l t o p and upper slopes. The north ridge i s occupied by lagopus and leucurus, the latter being uncommon because of the smooth, r o l l i n g topography i n most places on Nine-mile Mountain. Figure 42. Grant Creek area, southcentral B r i t i s h Columbia. This area contains a large population of lagopus, which 4500' Figure 40. Boulder Creek, Atlin, British Columbia South ridge 5300' North ridge 5 7 7 5 ' Figure 41. Nine-mile Mountoin, Hozelton, central British Columbio. Figure 42. Grant Creek area, neor Lorno Lake, east slope of Coast Range, southcentral British Columbia. 148 were not known to exist south of Kleena Kleene (about 200 miles to the north). A vegetation type which resembles closely habitats used by mutus i s present on plateaus and moderately sloping ridges at about 7,000 feet, yet no rock ptarmigan are found there as far as i s known. The other two ptarmigan inhabit zones simi-lar to those i n more northern areas. Figure 43• Eagle Creek, central Alaska. Two species of ptarmigan are present; leucurus i s lacking, probably due to the absence of extensive ledge-and-rockslide habitats. The h i l l s are rounded, with a broader low shrub zone than i n any other area vis i t e d except Paxson. L. lagopus confined to stream bottoms. Figure 44. Proximity of rock and willow ptarmigan nesting sites at Eagle Creek, Alaska. Illustrates the i n t e r d i g i t a -tion of the habitats of the two species wherever the slope i s gentle at certain altitudes. Figure 45. Mile 12, Denali Highway, near Paxson, Alaska. Although within the geographical limits of the range of leucurus, this area apparently contains only mutus and lagopus, as the h i l l s do not rise steeply enough to provide habitat for the white-tailed ptarmigan. Zone of mutus broader than lagopus. Dworfed birch and willow; some scattered alder clumps; sedge, many herbs, moss, lichens. Some exposed rock; Mesic community vO Valley bottom; toll willows, widely scattered spruce; mossy, some grovel I 3QOO' Figure 4 3 . Topographic and altitudinal changes in vegetation and ptarmigan distribution at Eagle Creek, Alaska. 150 •55 Rock Ptarmigan Nest Scale: l" = 100 yds and year •56Willow Ptarmigan Nest and year Figure 4 4 . Proximity of nesting sites of rock ond willow ptarmigan, Eagle Creek, Alaska. Figure 4 5 . Mile 12, Denoli Highway, near Paxson, central Alasko 152 Figure 46. Mount Arrowsmith, Vancouver Island, southern B r i t i s h Columbia. One species (leucurus) i s present. No zone of shrubs at timberline i n most places; coniferous forests end abruptly at rock slides or c l i f f s . The entire mountain i s surrounded by lowlands covered with evergreen forest types, and populations of leucurus are small and isolated. Figure 47. Sunwapta Pass and Columbia Icefields, Rocky Mountains, Alberta. L. leucurus i s the only species of ptarmigan present. As at Mount Arrowsmith, conifer forests end without an ecotone of shrubs. Depending on the rugged-ness of the terrain above timberline, leucurus may be rare or quite p l e n t i f u l . An examination of the sketches shows that the presence of each species of ptarmigan was associated with the occurrence of a particular form of arctic or alpine tundra. Wherever physiographic factors combined to cause the disappearance of one of those vegetative forms, the associated species of Lagopus was lacking. Therefore, the f i r s t requirement of a factor allegedly determining local distribution (that i t coin-cides with occupied zones) seems to be f u l f i l l e d . But i f vegetation structure or physiognomy i s corre-lated with the local distribution of ptarmigan, i s i t actually a causative factor, and i f so, how? Some logical p o s s i b i l i t i e s are: Figure 46- Mount Arrowsmith, Voncouver Island, British Columbia. Figure 47 Sunwapta Pass, Banff Notional Park and Columbia Icefields, Jasper National Park, Alberta. (1) That the structure of the vegetation i s the end result of the combined effect of many physical (climatic and edaphic) factors which, singly or i n combination, act directly upon ptarmigan to lim i t their distribution; (2) That the vegetation provides certain essential foods not found elsewhere; (3) That each type of vegetation provides certain kinds of shelter from predators which are used i n different ways by each species of Lagopus; (4) That interspecific competition among ptarmigan limits each species to the area wherein i t can compete best; (5) That each species of ptarmigan may select a particu-l a r kind of vegetation i n which to breed on the basis of innate or learned releasing mechanisms so that ptarmigan are limited psychologically, not physically, to a certain habitat. Each p o s s i b i l i t y i s discussed separately, although actually more than one factor may operate simultaneously. Physical Factors On the basis of general knowledge of the lives and habitats of ptarmigan, I suggest that i f differences i n physio-logic tolerances to the elements of weather, altitude, l i g h t , etc., are important i n causing the local separation of species in the breeding season, they are ultimate rather than proximate causes. As ultimate causes the alleged physiologic differences would act as the basis for natural selection; the survival of each species would depend, i n the long run, on the a b i l i t y of 156 i n d i v i d u a l s to choose habitats allowing optimal physiologic operation. The e x i s t i n g boundaries of any given population of ptarmigan, however, need not reach these physiologic l i m i t s . M i l l e r (194-2) phrased the idea i n t h i s way: Because an animal has an i n s t i n c t to s e l e c t and operate i n a c e r t a i n habitat, i s i t as a species a c t u a l l y l i m i t e d morphologically and p h y s i o l o g i c a l l y to t h i s environment? Is t h i s habitat as chosen the only one that would be adequate or approach an optimum f o r the species? I t seems that sometimes i t i s not, and that the s e l e c t i o n may l i m i t the occurrence of the species f a r short of the l i m i t i n g f a c t o r s involved i n n u t r i t i o n , reproduction and safety from predators. I t the present time i t i s not possible to be sure that p h y s i c a l f a c t o r s do not d i r e c t l y l i m i t the ecologic d i s t r i b u -t i o n of ptarmigan. However, i t does not seem l i k e l y , p r i m a r i l y because of the nature of the boundary. The l i m i t s of a popu-l a t i o n of any species of ptarmigan i n one area appeared to follow c e r t a i n changes i n vegetation form, as described already. I f such changes were abrupt, the l i m i t s of the range of ptar-migan were equally abrupt. Climatic changes, on the other hand, are much more gradual than t h i s , and one might expect a gradual grading o f f of the range of one ptarmigan to another i f c l i m a t i c f a c t o r s were l i m i t i n g . Furthermore, i s o l i n e s drawn for any single element of the weather would vary g r e a t l y from year to year on any one mountain; the ranges of ptarmigan do not seem to respond to these annual f l u c t u a t i o n s . As a r e s u l t , v a r i a t i o n s i n microclimate encountered within the area occu-pied by one species of ptarmigan may be greater than d i f f e r -ences e x i s t i n g between adjacent ranges of any two species! 157 Food Careful consideration was given to the p o s s i b i l i t y that contrasting habitat preferences among ptarmigan might be based on differences i n food supply. It i s impossible to reach any conclusions regarding the efficacy of food as a determinant of distribution, since there are so few data. It appears that several conditions would have to be f u l f i l l e d i f such were the case: (1) the a b i l i t y of each species to consume, digest or assimilate particular food items would have to d i f f e r , (2) these food items would have to constitute the major source of supply of some essential and c r i t i c a l nutritive elements, and (3 ) the range of the animal or plant containing the neces-sary dietary material would have to coincide with the range boundaries of the ptarmigan using i t . There i s no direct evidence relating to the f i r s t con-dition mentioned above. A cursory examination of foods consumed by ptarmigan (Table X) suggests that each species i s capable of u t i l i z i n g a variety of foods from the hatching of the chicks to maturity, and that the kinds of food eaten varies with geo-graphic location. This easts doubt upon, although by no means disproves, the hypothesis stated i n (l) above. The second assumption would have to be proven experi-mentally, and no data are available at present. Proof of the third point (that of coincidence of the food item and the range of the ptarmigan) would have to await the iden t i f i c a t i o n of the factor and the determination of i t s exact distribution. One botanic phenomenon of tundra communities may be pertinent here. Table X. Poods occurring i n crops of ptarmigan Pood Item, Plants mutus lagopus leucurus Scan. Asia CAA Can. Scot. G.-I. Al. Scan. Asia BC-Y NWT Nwf. Al. U.S. Can. Al Moss and lichens... PWS P PS Sp S S Sp Sp PS Equisetum sp. P SpS Sp E. arvense... S P E. variegatum P W PWSp Schizaea pus i l l a ... P Dryopteris spinulosa.. - P Polystichum W ? Abies sp. ... W. Juniperus sibenca ... w Picea sp. ... W Grass (unid.) S Sp s p Pestuca ovina PWS Poa sp. p Deschampsia w; P Galamagrostis neglecta .. s *Eeferences not cited individually. Por references used, see items marked (**) i n Literature Cited. Table X—Continued Food Item, Plants mutus lagopus leucurus Scan. Asia CAA Can. Scot. G.-I. Al. Scan. Asia BC-Y NWT Nwf. Al. U.S. Can. Al, Juneoides  spicatum... Eriophorum sp. Juncus sp. .. Oarex sp. . .. C.bigelowii 0. c a p i l l a r i s 0. misandra Luzula sp. L. arcuata .. L. eonfusa .. L. parviflora Scirpus cespitosus Rhynchospora alba Zigadenus  elegans .. Maianthemum  canadense. Salix sp. S. arctica . WS F F F F F F F ¥/ S F ¥ SF F SSpF S. S F F F S ¥SpSF F SSpF ¥ F WSp ¥ SpSF Table X—Continued Food Item, mutus lagopus leucurus Plants — — • — — — Sean. Asia CAA. Can. Scot. G.-I. Al. Scan. Asia BC-Y NWT Nwf. Al. U.S. Can. A l . S_. aurita.... ¥. S_. caprea ... ¥ S_. cineria .. ¥ S. co r d i f o l i a F S. glauca ... ¥ F F S. S. hastata .. ¥ S. herbaoea S F F FSp S. lanata ... S S_. lapponioum S¥ S_. l i v i d a ¥ S_. myrtiloides ¥ S_. nivalis .. • r S. phlebofolia ¥ S. p h y l i c i -f o l i a WS S_. polaris. F S. reticulata Sp $ Myrica gale•. Populus sp. Sp ¥ ¥ P. tremula... ¥ P. tremuloides w Table X—Continued Food Item, Plants Betula sp. B. glandulosa B. nana ... mutus lagopus leucurus Scan. As i a CAA, Can. Scot. G.-I. A l . Scan. As i a BC-Y NWT Nwf. A l . U.S. Can. Al, B. odorata.. B. pumila .. Alnus sp. .. Polygonum sp P. viviparum Oxyria digyna Rumex sp. ... Eriogonum p y r o l a e f o l i -um Arenaria sp. S t e l l a r i a sp. S. longipes Cerastium sp. C. alpinum .. Ranunculus sp. R. g l a c i a l i s R. pygmaeus W sw w SF FS F F S S F W F S Sp Sp s F F F F F S :SF • WSpS W Sp WF S SSpW F S S F F Sp Sp WSpS Sp Sp ¥ s s s TABLE X—Continued Pood Item, SBlM lagopus leucurus Plants Scan. Asia CAA Can. Scot. G.-I. A l . Scan. Asia BC-Y NWT Nwf. Al. U.S. Can. Al R. saxicola P R. sulphureus P Thalictrum alpinum S S Anemone sp. S A. vernalis S Caltha lepto-sepala . . .. S Papaver sp. P P. radicum... P W SP Draba sp. ... P D. cineria .. P D. subcapita W. Arabis petroea S Sedum diver-gens P Saxifraga sp. P S S S_. caespitosa P W £3. cernua. P P S. comosa P S_. hir c u l i s .. S S. nivalis .. W TABLE X—Continued mutus lagopus leucurus Food Item, ZZZZI plants -scan. Asia CAA Can. Scot. G.-I. Al. Scan. Asia BC-Y EWT Nwf. Al. U.S. Can. Al, S. oppositi-• fiolla FS W F S_. r i v u l a r i s F S. s t e l l a r i s F Fragaria sp. Luetkea pec-tinata ... Sibbaldia procumbens S Potentilla sp. F P. verna ... P. tridentata Sieversia longipes.. W Dryas sp. .. W F D. octopetala FS F Alchemilla  alpina ... Rosa nitida Rubus chamae-SpW F F Sp Sp F Sp SpF SpS Sp SpS SpW Sp morus F S F Table X—Continued Pood Item, •S&Sg l a S ° P u s l e u c u r u s Plants Scan. Asia CAA. Can. Scot. G.-I. Al. Scan. Asia BC-Y NWT Nwf. Al. U.S. Can. A l . Pyrus arbutifolia P Legume (unid.) P Lupinus l y a l l i i ... S S Astragalus alpinus S Oxytropis sp. P Hedysarum sp. P Geraneum sp. S Empetrum nigrum SW PS Sp SSp W S S P PS Ledum sp. ... S P L. groen-land icum .. Sp P Sp L. palustre.. P W Rhododendron canadense.. P Loiseleuria procumbens W Sp Phyllodoce  empetrifor-mis S S S PS Table X—Continued Food Item, mutus lagopus leucurus Plants — — — — — — — — — — — — — — — — — — ^ - — ————————————_—_—__—_____———_ Scan. Asia CAA. Can. Scot. G.-L A l . Scan. Asia BC-Y NWT Nwf. Al. U.S. Can. A l . Andromeda polif;olia W A. glauco-phylla ... F Chamaedaphne calyculata F Cassiope sp. S S F G. tetragona SF W 0. mertensiana S Kalmia p o l i -f o l i a F Sp ArctostaphylQ,s sp SSp S A. alpina ... ¥S SF S A. rubra .... SpF F F A. u5/a-ursi. ¥ F Caliuna vulgaris... Sp Sp ¥ Gaylussacia baccata ... F Vaccinium sp. Sp F ¥ FS S S F V. angusti-folium .... p Table X—Continued Pood Item, m u t u s lagopus leuourus Plants Sean. Asia CAA. Can. Scot. G.-I. Al. Scan. Asia BC-Y N¥T Nwf. A l . U.S. Can. Al. V. myrtillus Sp V. oxycoccos p V. uliginosum W PS P S¥ V. vitis-idaea W S P Dodeeatheon sp. S Gentiana sp. S Thymus serpyllum.. Sp Veronica sp. P Pedicularis sp. S P P. flammea .. P Galium saxa-t i l e Sp Linnaea borealis... ¥ Viburnum cassinoides p Antennaria alpina S Taraxaeum arcticum. S T. croceum... S Prenanthes t r i f o l i a t a P TABLE X--Continued Food Item, mutus lagopus leucurus Animals •—————• _______ Scan. Asia CAA Can. Scot. G.-I. Al. Scan. Asia BC-Y NWT Nwf. Al. U.S. Can. Al. Mollusca ... S Arthropoda S Arachnida Araneida.. S S SpF S FS Insecta Thysanura S Orthoptera S S Hemiptera S S Homoptera S Aphidae S S Coleoptera S S S Staphylini-dae S Coccinelli-dae S Chrysomeli-dae S Neuroptera F Mecoptera.. F Trichoptera Sp Lepidoptera S S S S Hymenoptera S S Tenthredi-nidae .... S Ichneumoni-dae S TABLE X—Continued Pood Item, m u t u s lagopus leucurus Animals Scan. Asia CAA. Can. Scot. G.-I. A l . Scan. Asia BC-Y NWT Nwf. A l . U.S. Can. Al. Pormicidae S S Diptera S S. SP s s s Tipulidae s_ Mycetophil-Gulicidae P s Simuliidae P s Seatophag- s. Ceratopogon- s Key to Locations and Symbols: Sp = Spring; S = Summer; P = P a l l ; W = Winter. Al. = Alaska Nwf. = Newfoundland BC-Y = B r i t i s h Columbia, Yukon Territory (Canada) CAA. = Canadian Arctic Archipelago Can. = Canada (excepting places l i s t e d separately) NWT = Northwest Territories (Canada) Scan. = Scandinavia Scot. = Scotland U.S. = United States (except Alaska) G.-I. = Greenland - Iceland 169 A number of plants i n arctic and alpine areas have a wide a l t i -tudinal and lati t u d i n a l range, transgressing vegetation types of widely differing structure or form, and often occurring on several sites. Por example, some willows grow as t a l l shrubs in the forest-tundra ecotone, as low shrubs i n the intermedi-ate zone and as prostrate or creeping plants i n high alpine or high arctic areas. Species of Dryas are found on gravel bars at and below timberline, on hummocks i n timberline marshes, and on dry, windswept slopes throughout the whole tundra biome. The same i s true of Gassiope tetragona, Polygonum viviparum, Epilobium anagallidiformis and other kinds of plants, many of which are eaten by every species of ptarmigan. Of course, there are many species of plants, mostly perennial forbs, roughly confined to the habitat of one ptarmigan. It i s i n this group of plants that one might expect to find a species f u l f i l l i n g a l l of the above requirements, i f such a species exists at a l l . Escape from Predators It i s probable that within i t s own habitat, each species of ptarmigan has developed certain adaptive features related to more ef f i c i e n t escape from predators. The d i f f e r -ence in plumage coloration of adults and chicks, for example, certainly are correlated with better concealment i n plant-covered versus rocky habitats. Certain behavioral features may be related to escape from predatory birds and mammals: willow ptarmigan have a peculiar " s t a l l i n g climb" just before landing, which may allow them to land i n small openings i n 170 dense shrubbery. Rock ptarmigan occasionally use this type of f l i g h t pattern in escaping, but usually prefer.: to s a i l away, depending upon distance and the curve of a h i l l to hide them. White-tailed ptarmigan either run away over steep and rocky terrain or f l y a considerable distance when flushed. However, i t seems l i k e l y that these adaptations developed secondarily after ecologic separation had occurred. I am not aware of any case where predators have been suggested as a factor limiting either ecologic or geographic distribution of birds. Competition If active competition existed as a means of separating ptarmigan i n the breeding season then interspecific s t r i f e (including actual or Ritualized combat) would be observed i n the f i e l d . There was no hint of such s t r i f e i n my own studies, and no reference to i t could be found i n the literature. The tendency of ptarmigan to occupy the same types of vegetation whether or not adjacent tundra areas contain other species of Lagopus also suggests the ineffectiveness of active competition. It appears that i f competition ever existed as a factor l i m i t -ing ptarmigan to the places where they l i v e , active s t r i f e has been replaced by an i n t r i n s i c mechanism for recognition of proper habitat which no longer requires contact with r i v a l species to determine range l i m i t s . Interspecific competition could occur when two species, originating from a common ancestral form, came into contact with each other after isolation. The result of this competition 171 would be a strengthening of the p a r t i a l l y effective ecologic separation mechanisms which evolved during the period of i s o -l a t i o n and differentiation. Luring geographic isolation (which most ornithologists agree i s necessary to the divergence and differentiation of species) each incipient species would develop morphologic and ethologic differences. This might occur through the operation of selection i n two dissimilar environments, or, i f the habitats used by the two populations were similar, through the operation of genetic d r i f t . In most cases both phenomena would be partly responsible for the differentiation which f i n a l l y occurred. When the two forms (now species) met again i n one l o c a l i t y , competition might arise between them i f there was an incomplete separation of niches or habitats. In the course of active interspecific competition the preadapta-tion which occurred during isolation would be important i n the f i n a l ecologic separation of the two species. In addition, habitat selection mechanisms of a behavioristic type might arise to heighten the degree of separation. Salomonsen (1955) came to such a conclusion; he stated that It i s most l i k e l y to assume that the ecological d i f f e r -ences between two sympatric species are preceded by a certain degree of pre-adaptation. This took place while the two species were geographically isolated and was an unavoidable result of intraspecific competition. It i s highly improbable that the ecological development should be exactly similar i n two completely isolated species. Vegetation Structure and Habitat Selection It has been established tentatively that the ecologic distribution of ptarmigan can be described i n terms of vegeta-tion structure or, i n the ease of leucurus, i n terms of the 172 physical aspects of terrain. Various factors have been examined which might be causally related to that primary observation, and i t was found that apparently no simple relationship with food, interspecific competition or shelter from predators or climatic elements could be described. On the basis of those findings, i t i s postulated that features of microterrain and vegetation form act as key stimuli of habitat selection mechanisms i n ptarmigan. It i s suggested also that the behavior patterns involved i n habitat selection act so that ptarmigan choose to live i n areas well within limits set by physiologic tolerances. It i s also possible for the features of the landscape which act as visual cues to be of no particular direct survival benefit to the species. Three important questions concerning habitat selection are: (1) i s the behavior pattern innate or learned, (2) when does i t occur, and (3) what are the stimuli? At the present time i t i s possible to discuss those questions only i n a very brief and incomplete fashion. There are no clues as to whether habi-tat selection i n ptarmigan i s innate or learned (or a combination of the two). If i t i s learned, the learning might take place while the chick i s very young and while i t i s s t i l l i n the v i c i n i t y of the territory and nesting s i t e . The characteristics of the habitat at that time are greatly different from those of the same place i n spring, when the segregation of the species occurs. This complicates learning and selection processes greatly. If an innate releasing mechanism were involved there would be no 173 necessity for transferring knowledge gained at one season to a situation present at another season. The actual selection of different habitats by ptarmigan occurs early i n the spring. At times i t appears that the i n i t i a l selection of a general area takes place while the birds are s t i l l i n loose flocks or courting groups, as groups of one species already show a tendency to segregate a l t i t u d i n a l l y i n April (in the region covered in the present study). However, the choice of a specific l o c a l i t y i n which further breeding a c t i v i t i e s are carried out is accomplished when the territory i s established. It i s probable that the male selects as well as defends the territory. To the observer the spring environment of ptarmigan seems extremely simple: the level or undulating tundra i s deeply covered with snow, with only occasional clusters of willow shrubs to break the dazzling whiteness of the scene; on the slopes surrounding the valleys dark patches appear where the wind has swept the ground clear of snow; higher s t i l l , grey ledges and boulders jut out of the thinning snow. The basic features which offer p o s s i b i l i t i e s for habitat choice among ptarmigan are the degree of slope of the land, shrubs, dark patches of snow-free ground and boulders or out-thrust ledges. It seems l i k e l y that the most important elements i n the habitat as far as selection mechanisms are concerned are those which are used by the male for daytime resting cover. Lack (1933) and Svardson (1949) both discuss cases where roosting or perching places of males are important i n habitat 174-selection. It i s i n that diurnal cover that male ptarmigan spend most of their time, and more important, i t is from the diurnal cover that the cock watches for intruding males of the same species and advertises i t s presence by ca l l i n g . If the local topography i s f l a t or gently r o l l i n g , and i f t a l l shrubs are v i s i b l e above the snow, the area may be occupied by willow ptarmigan. If the land i s h i l l y , with snow-free patches on knolls or on slopes, rock ptarmigan may settle there. For white-tailed ptarmigan the essential feature may be rough terrain, with boulders and ledges on which the birds can rest and feed. Modifications of the hypothesis w i l l be necessary as more information i s gathered. There are suggestions that cer-tain populations of ptarmigan liv e i n areas where the habitat selection stimuli proposed here do not exist. For example, individual willow ptarmigan may breed i n coastal areas of northern Alaska where no t a l l shrubs are present. T a l l shrubs are found i n places i n that region, such as along river bottoms, and are used by breeding willow ptarmigan. Perhaps flocks of ptarmigan settle i n spring wherever they find shrubs r i s i n g above the snow, later spreading into adjacent shrubless areas (possibly because of population pressures) to set up t e r r i t o r i e s and to nest. There i s some indication also that rock ptarmigan may breed i n shrubless areas i n the Canadian Arctic Archipelago, despite the consistency with which nests of mutus are placed under small shrubs i n low arctic and subarctic regions. It may be that i n both of the above cases different cues are important 175 i n habitat selection i n different places; the separation of species i s s t i l l complete. Geographic Distribution of Ptarmigan The geographic distribution of a species i s partly a reflection of the sum of i t s ecologic tolerances i n local areas and the slight modifications of those tolerances that occur i n different populations. It is also the result of the place of origin of the species, i t s mechanisms for dispersal and the influence of geo-historic events. The effect of temporal fac-tors may be noticeable particularly i n the distribution of north-temperate or arctic species, due to the tremendous changes brought about by the waxing and waning of continental glaciers. It i s convenient to divide ecologic factors into- those which have a direct effect on the well-being of ptarmigan (here-after called "ecologic" factors) and those which are suggested to be important i n habitat selection (termed, for lack of a better word, "psychologic" factors). Three main subdivisions can be recognized within the f i r s t category: certain aspects of vegetation, direct climatic effects and broad physiographic barriers. This outline i s set up only to aid in c l a r i f y i n g the discussion; i n r e a l i t y each category blends with others. Ecologic Factors Vegetation.—It i s l i k e l y that the southern lim i t of lagopus i n the coastal mountains of B r i t i s h Columbia and in the Rocky Mountains of Canada i s influenced by the scarcity of t a l l shrub tundra communities. Many factors probably are involved, 176 only the most obvious of which became apparent i n the present study. Most important, perhaps, i s the simple fact that timber-lines occur at higher elevations i n southern than i n northern areas. In southern regions a steeper, more rugged type of topography i s common at and above timberline; conditions are not favorable for the development of shrub communities and there is an abrupt transition between forested and alpine areas. Snow-f a l l i s generally greater i n B r i t i s h Columbian mountains than over most of the North American range of lagopus, and very often the few shrubs present at timberline are deeply blanketed and unavailable to willow ptarmigan as sources of winter food. Perhaps winter food supply i s more l i k e l y to be c r i t i -cal than nesting or brood covers for mutus and lagopus i n southcentral B r i t i s h Columbia. In addition to the factor of snow cover just mentioned, shrubby forms of Salix and Betula seemed to be much less frequent at timberline i n the Rocky Mountains near Jasper National Park, Alberta, and i n the Coast and Cascade Ranges of Washington and B r i t i s h Columbia than i n the northern Cordilleran region. Thus, f l o r i s t i c composition, as well as vegetation structure and snow cover, may be impor-tant. The winter habitat may support only such birds as can take f u l l advantage of the following food sources: (l) the few pockets of shrubs which remain above the snow i n alpine areas; ( 2 ) windswept alpine ridges; and ( 3 ) conifers at timberline. The white-tailed ptarmigan i s the only species of Lagopus known to make use of a l l three sources. Those general observations of timberline conditions i n 177 southern arctic-alpine regions are supported by the more quanti-tative studies of botanists. The contrast between arctic and arctic-alpine vegetation was discussed i n a paper by Bliss (1956) i n which he compared the "life-spectra" of tundra i n Wyoming (Snowy Range) and northern Alaska (Umiat). In the for-mer area i t was found that nanophanaerophytes (plants bearing wintering buds between .25-2 meters above the ground) occurred with extreme r a r i t y except i n wet meadows near timberline, where they formed about 12 percent of the f l o r a . By contrast, several sites at Umiat (south-facing slopes, coastal plain and other low-altitude areas) contained from 9-20 percent nanophanaero-phytes. In the Olympic Mountains of Washington, Jones (1936) defined the arctic-alpine zone as "that zone i n which phanaero-phytes and therophytes (annuals) are entirely absent, i n which chamaephytes (herbaceous and woody low plants with buds close to the ground) constitute more than 20 percent, and i n which hemicryptophytes (regenerating buds at s o i l level) dominate." The adjacent Hudsonian zone possessed a relatively small number of phanaerophytes (between .25 and 5 meters), most of which were found i n serai stages of hydrarch or xerarch succession. There-fore, i f those two botanic studies are indicative of general conditions, i t appears that arctic-alpine areas contain very few shrubs between .25 and 2 meters i n height i n comparison to low-arctic areas. F l o r i s t i c considerations may be important i n connection with the distribution and abundance of lagopus i n Newfoundland. According to Peters (in l i t ) , lagopus inhabits areas on the 178 Avalon Peninsula which are similar i n general appearance to regions occupied on the Canadian mainland, but of rather d i f -ferent f l o r a l composition. The ptarmigan thrive on foods available i n the Newfoundland f l o r a f u l l y as well as they l i v e on other species i n different regions. However, one shrubby Ericaceae (Kalmia angustifolia) i s eaten rarely although i t i s found i n nearly a l l areas of the Avalon Peninsula and i s used as nesting cover. Kalmia apparently competes successfully with other preferred food plants such as Vaccinium angustifolium and replaces them after burning. In places where Kalmia i s domi-nant, willow ptarmigan populations decline markedly. Direct climatic effects.—There are undoubtedly many regions i n North America where the climate would bring to bear intolerable stresses on ptarmigan regardless of how suitable the vegetation structure and food were. Nevertheless, I believe that the direct effects of climate are rarely manifest i n the present distributional limits of ptarmigan i n North America. As mentioned before, i t seems l i k e l y that each species has evolved a system of habitat selection by which i t chooses areas of optimal climate, thereby: avoiding direct physiologic stresses imposed by climatic elements. That may not be true of ptarmigan everywhere. Voipio (1950) discussed the sudden, periodic, extensive fluctuations i n the range of lagopus i n Finland which occurred i n response to severe climatic changes. Some local populations i n that area (which i s the southern l i m i t of lagopus i n the region) became extinct during unfavorable warm periods. At the same time, however, a few populations survived i n those southern 179 areas, perhaps because the individuals possessed greater a b i l i -ties to tolerate the temperature and moisture fluctuations which occurred. If that situation i s interpreted i n the lig h t of suggestions i n the present study, i t would appear that cer-tain areas i n central and southern Finland possess vegetational features which release habitat selection mechanisms i n willow ptarmigan. Those areas are very elose to the limits of c l i -matic tolerance of the ptarmigan. In favorable years pioneer birds from northern Finland become established i n the climat-i c a l l y marginal areas, only to become extinct when unfavorable conditions recur. Because of genetic variation inherent i n the species, a few of the populations survive the unfavorable periods, and are more or less permanent. Problems presented by closely related species which occupy distinct breeding ranges, such as were investigated i n the ptarmigan research, also have been studied from the physio-logic viewpoint. For example, Salt (1952) demonstrated experi-mentally that each of three species of finches (genus Carpo-dacus) had a s l i g h t l y different optimal range with respect to temperature and humidity* He then tested the correlation of those differences with the breeding range of each species. The results are summarized i n this way: When a l l these data are organized, the picture emerges of three morphologically similar species of the same genus, each so adapted i n physiological and psycho-logical mechanisms that i t can breed in an area of dis-crete climatic and vegetational character more e f f i c i e n t l y than either of i t s sister species which occupy adjacent but different areas. Climate, vegetation, and behavior patterns a l l play a part in defining the individual breeding ranges, one factor being c r i t i c a l i n one area, another factor being c r i t i c a l elsewhere. 180 In the f i n a l analysis i t i s entirely possible that a similar situation exists among ptarmigan. The information available at present, however, points to vegetation as the chief controlling factor, with direct effects of climate largely nonoperative. Broad physiographic barriers.—Various physiographic features or characteristics may act as limits of distribution. The southern lim i t of leucurus (as well as the boundaries be-tween a l l of the discontinuous ranges of the species i n the United States) probably is determined by the occurrence of alpine tundra on mountains. Climatic conditions under which tundra develops are found at increasingly higher elevations i n southern latitudes; wherever mountain masses are not high enough to reach those conditions, ptarmigan simply cannot exist. In a somewhat less obvious way, physiography and physchologic factors may combine to prevent hill-dwelling mutus from occupying coastal plains and marshes i n western and north-ern Alaska. The broad arc of f l a t or r o l l i n g terrain i n the valleys of the Tanana, Yukon, Kuskokwim and Nushugak Rivers of Alaska may act as a barrier to the northward dispersal of leucurus. In the lat t e r case a temporal factor may be involved as well. Psychologic Factors The same psychologic factors causing local breeding-season segregation of ptarmigan may be p a r t i a l l y responsible for their geographic limi t s . The eastward expansion of leucurus into the Northwest Territories may be prevented by the absence of suitable cues which could stimulate habitat selec-181 tion. It i s probable that leucurus could eat the plants found on the "Barren Grounds"; presumably i t could survive the c l i -matic rigors of the region. But i t s breeding season haunts— rocky crags, escarpments, ledges and screes—are gone, replaced by a relatively featureless plain. Coastal areas i n western Alaska may be closed to leucurus for the same reason. The northern l i m i t ; of lagopus i n the Canadian Arctic Archipelago apparently coincides with the limit of relatively luxuriant, partly shrubby vegetation. The absence of t a l l shrubs acting as breeding habitat selection stimuli may account for the lack of willow ptarmigan farther north. As a p i c t o r i a l summary of the combined roles of physio-graphic, ecologic and psychologic factors i n the distribution of ptarmigan, a semi-schematic "transect" was drawn (Figure 48) which represents areas from northern Alaska to New Mexico. Specific areas visited by the writer were used to represent much larger regions, so that some departure from actual condi-tions i s inevitable. The v e r t i c a l scale i s grossly exaggerated and the horizontal scale is not necessarily equal between a l l points of the transect. Geo-historic Events The ranges of many arctic species have undergone many complex changes during the Pleistocene period. With ptarmigan the most recent trend was probably a general expansion of ranges except for leucurus i n the southern Rocky Mountains. Geologists do not agree i n their estimates of the time since the last glaciation, although most evidence indicates that physiographic 15,000' 15,000' o White-tailed Ptarmigan x Rock Ptarmigan •it Willow Ptarmigan —- Timberline Figure 48, Topographic diagram of the distribution of ptarmigon in western North America. 15,000' 15,000 Figure 48 . Continued. Figure 48. Continued. Figure 4 8. Continued. 186 features i n the region of the United States - Canadian border associated with the melting o f the last glacier were formed beginning 10,000 to 15,000 years ago (Flint, 1957,p. 290). Recent studies (Lawrence, 1958) have shown that vege-tation develops very rapidly after g l a c i a l recession under existing climatic conditions i n southeastern Alaska. At low altitudes, conifer forests may develop within 150-200 years after exposure of the s o i l . Even allowing for the probability that vegetation would not become established so quickly under cooler climatic regimes such as probably existed at the end of the last glaeiation, and such as prevail now at high altitudes, i t can be seen that the lag between gl a c i a l recession and tundra development i s rel a t i v e l y slight. As a result, the main elements which might have prevented ptarmigan from occu-pying a l l suitable areas i n western North America are factors which determine dispersal rate and the nature of the barriers which must be crossed. Although a l l three species have expanded their ranges in the last 10,000 years, i t appears that mutus and lagopus have succeeded i n establishing themselves i n most or a l l places providing proper conditions. One possible exception i s the absence of lagopus from Greenland. Some botanical descriptions of southern Greenland (Boeher, 1933; Longstaff, 1932) suggest that the vegetation may, i n some places, be very similar to that i n regions occupied by lagopus i n northern Canada. In that case the development of suitable vegetation may have been very recent, or the water barrier of Davis Strait may have 187 prevented the establishment of willow ptarmigan i n west Green-land . It is conceivable that temporal factors may be at work i n the limitation of mutus i n central B r i t i s h Columbia. The evidence i s poor, however, because the region has not been visited frequently enough by ornithologists to determine ex-actly where the most southerly populations exist. In August, 1958, the writer flew to Grant Creek, southwest of Williams Lake, B r i t i s h Columbia, and studied alpine areas there for two days. Only leucurus and lagopus were present. A few flat-topped ridges between the forested lowlands and the rugged eastern slope of the Coast Range contained vegetation similar to that i n which rock ptarmigan were seen a few hundred miles to the north. No mutus were seen; i n fact, several broods of lagopus were u t i l i z i n g "typical" rock ptarmigan nesting cover. The fact that lagopus broods were i n that vegetation type was not par-t i c u l a r l y unusual, but the lack of rock ptarmigan was puzzling. Of course, mutus populations might have been overlooked, a l -though biologists of the B r i t i s h Columbia Game Department who previously visited the area reported only willow and white-tailed ptarmigan (Larson Sugden, pers. comm.). But i f the species was not there, then three explanations seem possible: (l) areas of suitable habitat might be so small and scattered as to prevent the southward dispersal of the nearest popula-tions; (2) rock ptarmigan may have become established i n cen-t r a l B r i t i s h Columbia very recently, and may not have had time to reach the Grant Creek area; and (3) the climate or other 188 factors besides vegetation structure may be unfavorable. At present, leucurus i s not found north of the Alaska Range i n Alaska or the Ogilvie Range i n Yukon. From a super-f i c i a l examination of records of ornithologists and botanists who have visited the central Yukon region, there i s no apparent ecologic reason why leucurus should not inhabit most of the Mackenzie Mountains and mountains i n northcentral Yukon. Simi-l a r l y , the Kuskokwim Mountains i n southwest Alaska may be suitable to that species. Perhaps white-tailed ptarmigan w i l l establish themselves i n many areas of Yukon and Alaska not yet occupied. However, that i s only a guess, since there may be climatic or other barriers to dispersal that are not recognized at the present moment. 189 SUMMARY The main problem discussed in this report arose from an examination of the distributions of the three species of ptar-migan found i n western North America. Each species occupies broad areas alone, but there i s a region from central B r i t i s h Columbia to southcentral Alaska and Yukon i n which the ranges overlap. A study of the literature revealed two basic points: (1) that ptarmigan often occupied the same l o c a l i t i e s i n winter (occasionally i n the same flocks), and (2) that there was a great deal of confusion and vagueness regarding the ecologic separation of the three species of Lagopus i n the breeding season. In this investigation i t became clear that the separa-tion of the three ptarmigan during the summer was consistent and predictable. Therefore, the research was aimed at three fundamental questions: (l) What factors create the inter-specific boundaries between populations of the three ptarmigan? (2) Are those same factors involved i n the geographic d i s t r i -bution of the species as well? (3) When and on what basis are specific breeding areas chosen by individual ptarmigan? The contributions of l i f e history data to the analysis of the problems of distribution are primarily those concerned with social groupings. The functional groupings of ptarmigan provide a framework on which to describe the changing events i n 190 the annual cycle of individuals and populations. The essential parts of that cycle seem to be as follows: In midwinter (according to reports of other investigators) ptarmigan may be found i n large flocks or small, loosely organized groups, de-pending upon local weather and food conditions. The functional unit i s the flock; adult birds usually do not maintain pair bonds through the winter, and family units probably are dis-solved i n f a l l . If winter flocks are composed of individuals which have moved i n from distant areas, large migratory flocks form i n early spring, usually March or A p r i l . Flocks of r e s i -dent birds tend to disintegrate with the coming of spring, possibly as a result of the dual stimuli of reproductive urges and more favorable metabolic balances. For a brief period the usual aggregation of ptarmigan i s the courting party, composed of variable but small numbers of both sexes. Very quickly, how-ever, the processes of dispersal onto the breeding grounds, establishment of t e r r i t o r i e s and pairing begin. Because ptarmigan tend to be t e r r i t o r i a l and are monogamous for one season, a breeding population consists of paired birds scattered at intervals over the tundra. When the chicks hatch the spacing tends to break down as t e r r i t o r i e s are abandoned and as families wander about i n search for food and shelter. At the end of incubation a dichotomy appears i n the habits of ptarmigan: males of lagopus usually remain as an active part of the family group, while rock and white-tailed ptarmigan males desert their mates to spend the summer singly or (less often) i n small groups. In a l l species late summer 191 and autumn are times of the resurgence of gregariousness: broods join other broods, cocks join females and young to form flocks, and those flocks i n turn attract single birds or small-er groups to form large migratory or wintering aggregations. This brief sketch of the annual cycle of alternating socia-b i l i t y and t e r r i t o r i a l i t y suggests that the important time of separation of the species into distinct l o c a l i t i e s i s from the establishment of ter r i t o r i e s to the brood season—in terms of calendar time, from late April or early May to late June or early July. It i s probably i n this 60-day period that species-specific habitat choices are made. The places where ptarmigan l i v e i n summer can be divided into three categories: (1) diurnal covers, the center of act i v i t y of male ptarmigan holding t e r r i t o r i e s ; (2) nesting sites; and (3) brood covers. The greatest differences between species occurred i n the f i r s t category. In the region studied, willow ptarmigan males chose sites with wide outlook, overhead cover and restricted area (relative to the territory as a whole). Willow-lined creek banks, "islands" of shrubs i n marshy areas and raised hummocks with bushes were favored spots. Rock ptarmigan also chose places with wide outlook—perhaps to an even greater degree than lagopus—but without overhead cover. Barren, dryas— and graminoid-covered knolls on h i l l y ground were selected commonly. It should be emphasized that while the male of a mated pair of mutus very often was found i n such a place, the female of the pair might nest i n vegetation which was d i f f i c u l t to distinguish from that used by females of 192 adjacent populations of lagopus. White-tailed ptarmigan males were found most often at the "base of ledges or large boulders on high ridges or on mountainsides above areas occupied by the other species. However, i n one area there was no distinct altitudinal separation of mutus and leucurus males; the primary differences were in the selection of broken escarpments and extremely rocky areas by the latter species. The nest sites of rock and willow ptarmigan were not greatly different i n the arctic-alpine region studied. Each appeared to require a combination of shrubby and open vegeta-tion. Although the zone occupied by lagopus was, on the whole, characterized by the presence of t a l l e r shrubs than the tundra inhabited by mutus, a quantitative examination fa i l e d to demon-strate that difference. Very l i t t l e direct evidence was obtained on the sites used by leucurus for nesting. Observa-tions of mated pairs and broods, as well as information from the literature, suggest that leucurus nests i n stony, shrubless alpine areas, often near boulders or at the base of rocky out-eroppings. Vegetation types used by willow and rock ptarmigan broods were similar to nesting covers of the same species. Open areas apparently were necessary for ease of travel and feeding, while some shrubby cover was usually present. In the case of willow ptarmigan, at least, such shrubby areas were used by chicks as escape cover. A tendency was noted for older broods to move upward late i n July and August, resulting i n the occasional sighting of lagopus broods i n mutus nesting areas, 193 and mutus broods i n the broad zone inhabited by leucurus. Broods of white-tailed ptarmigan often were found i n the more moist sites of their rocky, sterile-appearing habitat. Therefore, the local distribution and separation of ptarmigan i n areas where several species were found together seemed to coincide with a particular vegetation structural type, or a unique combination of vegetation and topographic features. The following factors were discussed i n an attempt to determine how vegetation discontinuities could be important in ptarmigan distribution: (1) food, (2) climatic elements, (3) shelter from predators, (4) interspecific competition, and (5) ethologic aspects of habitat selection. It i s postulated that since the boundaries of local ptarmigan populations appear to be more sharply defined than changes i n climatic conditions, differences i n tolerance to physiologic stresses may be ultimate rather than proximate fac-tors. The proximate factors may be^differences i n the environ-mental stimuli which result i n habitat selection by individuals. It i s not essential that local distribution limits of each species actually approach the maximum limits of physiologic tolerance. If habitat selection takes place at the time territories are established, i t seems l i k e l y that the stimuli are connected with the slope of the land, physical aspects of microterrain or the presence or absence of shrubs r i s i n g above the snow. In general i t appears that the same factors which determine the distribution of ptarmigan at the local level also 194-may determine geographic distribution i f the additional factors associated with geo-historic events are taken into account. It i s probable that a l l species of Lagopus have expanded their continental ranges since the last great glaeiation. White-tailed ptarmigan (probably an offshoot of a population of mutus isolated many thousands of years ago i n the Rocky Moun-tains of the United States) seem to show the greatest influence of temporal factors in their distribution: the entire north-ern boundary of that species may not be a f i n a l ecologic boundary at a l l , but the temporary result of slow dispersal and physiographic barriers. The geographic distribution of ptarmigan, therefore, may result from any or a l l of the follow-ing factors: (l) the presence or absence of environmental features directly concerned with the survival of individuals; (2) the occurrence of the proper cues to habitat selection; and (3) the operation of the origin-time-barrier-dispersal rate complex. 195 LITERATURE CITED Allen, A. A. and P. P. Levine. 1935. A brief study of the willow ptarmigan and i t s relation to predators and Leucocytozoon disease. Trans. Twenty-first Amer. Game Conf.: 381T386. Allen, E. A. 1933. 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Can. Bull. 121, B i o l . Ser. 41. 400 pp. *Quick, H. P. 1948. Winter food of white-tailed ptarmigan in Colorado. Condor 49(6): 233-235. Rajala, P. 1958. The choice of grinding stones by capercaillie, black grouse and ptarmigan i n the li g h t of enclosure experiments. Suomen R i i s t a 12: 89-93. Rand, A. L. 1944. L i s t of Yukon birds and those of the Canol Road. Nat. Mus. Can. B u l l . 105, B i o l . Ser. 33-76 pp. Rausch, R. L. 1951. Studien an der Helminthenfauna von Alaska, Iv. Haploparaxis g a l l i sp. nov. ein Cestode aus dem Schneehuhn, Lagopus rupestris (Gmelin). Zeitschrift fur Parasitenkunde 15(1): 1-3. •Roberts, B. 1934. Notes on the birds of central and south-east Iceland, with special reference to food-habits. Ibis for 1934: 239-264. Salomonsen, P. 1939. Moults and sequence of plumages i n the rock ptarmigan (Lagopus mutus (Montin)). Videns. Medd. ffa. Danske Naturhist. Poren. 103: 491 pp. . 1950 . En ny race af fjaeldrype Lagopus mutus (Montin) f r a Gr/zfnland. 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LAGOPUS 208 ALLEGED HYBRID: L. MUTUS X L. LAGOPUS Collected: Nueltin Lake area, Northwest Territories, November 7, 1947. By Harper (1953). Characteristics on which Harper bases judgment: (1) In the company of three individuals of L. lagopus. (2) Depth of b i l l 8.5 mm. Maximum of eight mutus collected in the same area, 7.75 mm. Range fdr 12 subadult and adult lagopus collected by the author, 9«0-10.5 mm. (3) Upper t a i l coverts extend 5 mm. beyond rectrices, which i s more than the average of 1.8 mm. for mutus collected i n the area. (4) Primary number 9 densely speckled. Resembled a one-year-old female lagopus collected by the author. A l l rock ptarmigan shot from the area had pure white p r i -maries i f adult, or elongated brown blotches on primaries number 9 and 10 i f subadult. (5) Outer primary covert speckled. (6) White-tipped black feathers around the base of the b i l l and eye. (7) Weight 452 grams, which was less than any of thenmutus collected. Wing (180 mm.) smaller than other mutus. (8) Tarsus 32 mm., resembling mutus. Harper's conclusion: "the specimen may be regarded as either a highly aberrant individual of albus (L. lagopus albus) or a hybrid between the Willow and Rock Ptar-migan." 209 In my opinion, i t seems l i k e l y that the specimen was a rock ptarmigan with a deeper-than-average b i l l . Both mixed and pure flocks of mutus and lagopus are known, so that the author's f i r s t point means l i t t l e . Characters number 2 and 3 are i n -conclusive because of the small number of specimens used i n the comparisons. Young birds i n f i r s t winter plumage i n both mutus and lagopus have speckled or blotched primaries and coverts, so that characters number 4- and 5 are not decisive. Colored feathers (such as those around the eye i n the specimen i n ques-tion) appear i n the winter plumage of many rock and willow ptarmigan, especially from those collected i n southern areas. The weight of the specimen and the tarsus length, although not conclusive, resemble mutus more than lagopus. APPENDIX II WEIGHTS AND MEASUREMENTS OP PTARMIGAN 211 WEIGHTS AND MEASUREMENTS OP PTARMIGAN The weights and measurements of the ptarmigan specimens collected have no direct bearing on the main objectives of the present study. Therefore, the data given i n the succeeding tables are not analyzed s t a t i s t i c a l l y . However, the paucity of measurements of ptarmigan i n the literature makes any such information of potential value to systematists or others inter-ested i n distinguishing populations of avian species. The following tables were prepared to make the meristic data a v a i l -able . Two measurements taken on each specimen were omitted from the tables. One—length of longest toenail—was taken i n an attempt to determine when toenails are shed. However, the lengths varied considerably among individuals even at the same time of year, so that the value of the measurement was slight. The second—length of culmen—was discarded because of the d i f f i c u l t y of obtaining consistent measurements (mainly due to the small, closely appressed feathers covering the base of the upper mandible). Weights were taken with a triple-beam scale to the nearest .1 gram within a few hours after the bird was shot. If the crop contained more than 1 gram of food material, the crop was removed, weighed, and this value subtracted from the total weight. A few birds taken early i n May were weighed when c o l -lected, then weighed again i n February of the following year, after being frozen throughout the intervening period. The loss 212 of weight varied from 1 to 3 grams—practically negligible i n birds weighing 300-500 grams. Therefore, specimens not weighed before being frozen could be weighed afterward with some assur-ance that the true li v e weight was being approximated. Total length was measured from the tip of the b i l l when the head was pointed upward and the neck stretched to i t s f u l l -est normal extent, to the tip of the longest t a i l feather or covert. This measurement, as well as the wing, t a i l and foot measurements, were taken with a steel tape graduated i n 1/16 inch; later, conversions were made to the metric system. The t a i l was measured by bending the t a i l back so that the base of the rectrices could be located, and measuring from that point to the tip of the longest t a i l feather. Wings were measured by placing one end of a flexible steel tape on the bend of the wing, and measuring along the curve of the longest primary to i t s t i p . Measurement of the foot was accomplished by bending the foot at the tibi o - t a r s a l joint, and measuring from the outer part of the bend to the tip of the longest toe, including the toenail. B i l l width i s the width of the b i l l at the forward end of the n o s t r i l openings; the measurement of length i n c l u -ded i n the tables i s a measurement taken with vernier calipers from the anterior tip of the nostrils to the end of the upper mandible. Weights are expressed i n grams, and a l l other measure-ments are i n centimeters. Table XI. Willow Ptarmigan, May 1-3, 1957: Yukon and Bri t i s h Columbia Weight B i l l Gonads* Place Date Specimen Number Sex Crop Total Less Crop Total Length Ta i l Wing Foot Prom Nos-Width t r i l Left Right CD >s CQ U u o CD o +» M & -H Ct3 CD U hi -P M •H CD CQ ^ •H P) fin • O • P" CO t H 5/ 1/57 5/ 1/57 5/ 1/57 5/ 1/57 5/ 1/57 5/ 1/57 5/ 1/57 5/ 1/57 W2-57 W6-57 W7-57 W8-57 W5-57 Wl-57 W4-57 W9-57 M M M M M P P P 14.4 15.6 6.2 12.0 15.2 2.9 2.2 14.5 490.1 502.0 542.2 526.7 552.9 428.3 514.5 477.6 5/ 1/57 W3-57 8.7 438.3 35.9 12.1 19.0 8.9 .92 1.19 1.28 1.23 35.6 13.3 19.7 9.2 .98 1.20 .93 .74 37.5 12.4 19.0 8.9 .94 1.20 1.32 1.10 36.5 12.7 18.9 9.0 .95 1.15 1.16 .97 38.1 13.3 19.6 9.5 .97 1.16 .91 .90 34.0 11.4 18.1 8.3 .86 1.11 .37, .32 34.6 12.4 19.4 8.6 .96 1.16 .36, .32 34.3 12.1 18.1 8.7 .81 1.18 .50, .49,-46, .45 34.0 11.4 18.4 .81 1.02 Less than .2 5 36.5 11.7 19.2 8.3 .97 1.23 .95 .65 36.6 12.7 18.4 8.6 .99 1.19 1.05 .93 37.5 12.9 20.3 9.0 1.02 1.18 1.24 1.14 37.5 13.0 19.4 8.7 .96 1.20 1.11 1.05 35.0 13.0 19.8 9.2 .93 1.17 1.16 .98 33.3 13.0 19.6 8.9 .97 1.18 1..28 1.18 37.5 13.3 18.7 8.3 .91 1.16 .82 .79 35.2 11.7 18.9 7.9 .85 1.12 1.15 .91 35.9 12.4 19.6 8.7 .95 1.10 .96 .77 35.6 11.4 18.4 8.7 .90 1.16 36.2 12.5 19.0 8.3 .91 1.09 .32, .29,.27 36.8 12.1 19.0 8.6 .92 1.13 .31, .28 34.3 11.7 18.4 8.4 .90 1.10 .37, .35,.32 11.8 18.3 8.9 .91 1.14 11.9 17.4 8.9 .88 1.09 10.8 17.0 7.9 .86 1.05 T 3 cd o CQ • CD O ri • •H PP cti w ri u ». CD CQ -P CO CQ <J5 CD PM > -P -P ctJ U M o I—I J2J •H .ri o 5/ 2/57 5/ 2/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 3/57 5/ 8/57 5/11/57 5/17/57 W10-57 Wll-57 W13-57 W16-57 W-57 W16-57 WD-5 7 WE-57 W18-57 WP-57 W14-57 W15-57 W17-57 W19-57 W21-57 W24-57 M M M M M M M M M P P P P P P P 25.5 12.0 2.0 4.5 13.9 4.6 4.4 10.2 8.0 17.9 11.0 7.0 5.6 7.0 20.0 499.9 480.2 576.2 503.5 532.2 501.8 443.0 522.3 473.6 491.8 489.0 506.8 488.3 484.2 476.8 398.4 •Testes = length (and sometimes width) of each te s t i s . Ovary = diameter of largest ovules. Table XI—Continued Place Date Specimen Number Sex ¥eight Total Length T a i l ¥ing Poot B i l l Gonads Crop Total l e s s Crop ¥idth Prom Nos-t r i l L e f t Right 5/22/57 ¥25-57 F 8.1 521.9 11.1 18.4 8.3 .98 1.05 2.88,2.44, 1.81 5/24-/57 ¥26-57 F 21.4 497.7 35.1 11.4 18.6 8.3 .89 1.08 .73,.58,.52 5/10/57 ¥20-57 M ? 474.0 12.7 19-0 .90 1.12 5/11/57 W22-57 M 18.0 538.5 12.7 19.2 9.4 .93 1.25 5/17/57 ¥23-57 M 2.5 483.0 12.4 19.6 9.3 .92 1.23 Table XII. Willow ptarmigan, June-July, 1957-1958: Chilkat Pass, B r i t i s h Columbia CD o CD i—I Weight B i l l Gonads Specimen Date Number Sex Crop Total Less Crop Length T a i l Wing Foot Width From Nos-t r i l Left Right 6/18/57 6/18/57 6/25/57 6/29/57 7/10/57 o 7/20/57 m 6A/5 7 • 6/29/57 S 6/29/57 «J 7/10/57 * 7/20/57 -p S 6/16/58 3 6/20/58 6/27/58 6/29/58 6/27/58 o W33-•57 M 4.0 539.5 37.5 12.4 20.2 8.9 .92 1.18 1.49 1.25 W34-•57 M 3.1 534.4 36.6 11.7 19.6 8.9 1.07 1.29 1.07 1.08 W39-•57 M 3.3 502.4 35.9 12.1 19.4 8.7 .96 1.24 1.17 1.08 W44-•57 M 5.6 498.0 38.1 12.1 19.6 8.6 .96 1.15 1.33 1.38 W46-•57 M - 505.2 12.1 19.0 8.3 B i l l .75 .77 Crushed W50-•57 M 5.8 466.3 38.1 12.1 19.0 8.1 .93 1.14 .54 .54 W27-•57 F 7.0 610.0* 36.2 11.4 17.8 7.6 .91 1.13 2.23,1.88 W42-•57 F 4.6 411.2 34.3 9.5 17.5 8.4 .82 1.06 W43-•57 F — 490.2 37.1 11.1 18.4 8.9 .91 1.11 W47-•57 F - 391.4 35.2 11.4 18.4 7.8 .92 1.05 Very small . ova W49-•57 F 3.5 448.4 37.1 11.6 18.4 8.3 .87 .98 Regressed W 4-•58 M 542.2 38.7 13.0 19.1 8.9 .93 1.09 1.19 x.80 1.08 x W 5-•58 M 6.3 519.2 39.3 14.0 19.4 9.2 .88 1.06 1.36 x.88 1.21 x W12-•58 M — 473.1 38.1 12.4 18.9 8.6 .98 1.12 1.15 x.86 1.20 x W21-•58 M — 488.8 38.7 13.5 19.9 8.9 .97 1.12 .85 x.59 .84 x W13-•58 F _ 396.5 36.5 11.9 17.9 8.3 .88 1.08 *Adult weighed more than scale would measure. Table XIII. Willow ptarmigan, August-September, 1957-1958 Weight Specimen Date Number Sex 8/ 1/57 W54-•57 M 8/ 1/57 W56-•57 M 8/18/57 W60-•57 M 8/18/57 W62-•57 M 9/ 6/57 W69-•57 M 8/25/57 W63-•57 M 8/25/57 ¥64-•57 M 8/ 1/57 ¥55-•57 F 8/ 8/57 ¥59-•57 F 9/ 1/57 ¥67-•57 F 8/25/57 ¥65-•57 F 6/ 5/58 ¥ 1-•58 M 6/10/58 W 3-•58 M 7/24/58 ¥25-•58 . M 8/ 5/58 ¥32-•58 M 6/ 5/58 ¥ 2-•58 F 7/24/58 ¥26-•58 F Total Less Crop Crop B i l l Gonads Total Length From T a i l Wing Foot Nos-t r i l Left Right 1.09 .51 .51 1.07 .57 .57 1.16 .62 .69 1.14 .53 .53 1.13 .52 .52 .53 .55 1.02 Regressed 1.17 Regressed 1.06 Regressed 1.09 Regressed 1.14 L36 xL02 broken 1.10 1.30 x.85 1.28x .79 1.09 .53 L .53 L 1.13 .69 x .35 .63 x .33 -p CO M co H CQ - H CO A PH o A t l i n I CQ r H - P CQ •H CO CO & X P H o A t l i n Hazel-ton Creek Lorna Lake Hazel-ton Eagle Creek Alaska Lorna W28-58 W34-58 F F 12.4 481.3 37.1 12.4 18.1 468.8 36.0 12.7 8.7 515.9 36.3 11.7 11.1 489.9 12.5 16.7 557.8 38.4 11.4 — 471.6 36.5 12.1 2.5 507.5 36.8 13.0 2.0 429.9 34.9 10.5 5.8 413.3 33.7 10.5 3.8 437.0 34.6 10.5 - 482.2 35.6 10.8 12.0 463.9 38.4 13.2 5.0 496.0 38.4 13.0 ? 522.0 39.3 12.7 — 520.0 37.0 11.7 414.0 36.2 10.8 35.9 11.7 36.2 19.2 18.7 18.1 19.4 19.0 19.4 20.2 17.8 17.8 17.6 18.6 19.5 19.5 19.6 19.6 7.9 8.1 8.4 8.6 8.9 8.4 8.3 7.9 8.1 7.9 8.3 8.9 8.3 8.3 .93 .86 .91 .93 1.02 .94 1.03 .91 .85 .88 .95 .92 .94 1.05 8.6 .88 1.06 2.51,1.41,1.00 8.3 .94 1.11 Reduced 17.8 18.1 7.6 7.3 .84 1.01 .87 1.12 Reduced Reduced Table XIV. Willow ptarmigan, winter 1956-1957: Saskatchewan and Alaska Weight Place Date Specimen Number Sex Crop Total Less T o t a l Crop Length B i l l T a i l Wing Foot From Width N o s t r i l cd cd r H CO CO cd 3 H CQ T3 •H ft cd • PA M to >» cd ri to o +> CO 11/ 9/56 11/13/56 11/13/56 11/ 9/56 11/13/56 11/13/56 11/27/57 12/11/57 11/26/57 11/27/57 12/11/57 12/11/57 12/11/57 12/11/57 12/11/57 3/30/58 A56-•2 M 60.4 598.4 40.2 14.0 20.6 9.5 1.01 1.22 A56-•4 F 81.9 440.5 38.7 12.4 19.0 8.9 .93 1.15 A56-•1 F 32.2 453.2 35.9 12.7 18.4 8.3 .91 1.07 A56-•3 F 35.0 388.4 35.9. 11.4 18.7 7.9 . .87 A56-•5 F 62.5 525.5 40.0 13.0 19.9 9.5 .99 1.12 A56-•6 F 14.3 425.7 36.8 12.9 18.7 8.6 .88 1.16 S23 M 53.4 658.1 39.9 12.7 19.6 8.9 .88 1.25 S29 *> 30.7 517.8 36.2 18.4 8.9 .86 1.11 S21 F. 47.7 459.5 36.2 12.7 19.0 8.9 .90 1.13 S22 F 14.5 593.5 36.8 12.7 19.0 8.9 .83 1.17 S24 F 28.2 535.3 38.1 12.7 19.0 8.9 .85 1.11 S25 F 13.3 520.2 37.5 12.7 19.0 8.9 .88 1.09 S26 F 49.2 544.3 38.7 13.0 19.9 8.8 .92 1.26 S27 F 36.5 496.7 38.1 12.7 18.4 7.9 .84 1.07 S28 F 4.8 543.7 34.9 12.1 19.0 8.9 .85 1.12 S30 F 6.9 483.6 38.7 13.0 19.2 8.3 .85 .98 Table XV. White-tailed ptarmigan, May-August, 1957-1958 Place Date Speci-men Number Sex Crop Total Less Crop Total Length T a i l Wing Poot B i l l Prom Width Gonads Left Right Chilkat 5/ 3/57 WT2-57 M 24.5 346.2 32.4 10.8 18.4 7.6 .83 1.11 .83 .74 Pass 5/18/57 WT3-57 M - 327.5 32.4 10.8 18.1 7.3 .83 .99 1.29 1.23 Banff 5/27/58 WT1-58 M — 275.6 32.7 9.8 17.8 7.0 .76 .91 1.09 x .84 1.07 x.76 Peak 5/27/58 WT2-58 M 2.9 277.5 30.8 9.8 17.6 7.0 .81 .92 1.05x .77 .99 x.74 Hazelton 6/ 5/58 WT4-58 M 2.1 292.2 33.3 11.1 18.7 7.8 .81 1.05 lJ.7x .92 1.17 x.85 Hazelton 6/ 5/58 WT5-58 . M 3.5 289.3 32.4 10.5 18.1 7.6 .82 1.03 1.24x .88 1.12 x.78 At l i n 6/11/58 WT6-58 M 6.6 293.2 33?0 10.8 18.1 7.0 .78 1.15 x .81 1.10 x.80 At l i n 6/11/58 WT7-58 M - 278.4 32.1 10.5 18.1 7.3 .78 1.07 1.38 x .91 1.30x.91 Chilkat 6/29/57 WT5-57 M — 305.6 31.4 9.8 17.5 7.3 .84 1.04 .94 .84 Pass 7/ 1/58 WT14-58 M 2.1 285.1 30.5 10.2 17.6 7.5 .78 1.04 1.09 x .78 1.09 x.75 Chilkat 5/ 2/57 WT1-57 F 15.0 275.0 30.8 9.8 18.1 7.6 .78 .96 Not v i s i b l e Pass 5/18/57 WT4-57 F 9.7 355.3 28.9 10.5 17.5 7.1 .81 .99 1.46,1.15 Banff Pk 5/27/58 WT3-58 P 7.9 297.7 30.5 9.2 17.5 6.3 .75 .87 .49,-49 Chilkat 6/29/57 WT6-57 P — 311.1 32.4 11.1 18.1 7.0 .76 1.03 Pass 6/30/58 WT8-58 P ? 336.6 32.7 10.5 17.8 7.3 .79 1.03 Reduced Chilkat 7/ 4/58 WT15-58 P 61.0 322.0 31.8 10.2 17.9 7.2 .80 1.05 Reduced Pass 7/ 8/58 WT16-58 P - 334.5 31.8 10.2 17.4 7.6 .79 1.08 Reduced Lorna Lk 8/ 4/58 WT17-58 M 34.0 10.2 18.4 7.6 .76 1.04 A t l i n 8/25/57 WT17-57 M 6.4 332.1 30.4 9.8 17.9 7.6 .82 1.05 .53 .53 A t l i n 8/25/57 WT18-57 M 4.2 318.6 31.3 10.2 17.8 7.1 .78 1.03 .44 .44 Lorna Lk 8/ 4/58 WT18-58 P 35.2 11.1 19.0 7.6 .83 1.01 Regressed At l i n 8/25/57 WT126-57 P - 341.8 30.2 8.6 17.5 9-7 .78 1.02 Regressed A t l i n 8/25/57 WT15-57 P 3.6 302.4 30.5 8.9 17.8 7.5 .77 1.04 Regressed Table XVI. White-tailed ptarmigan, September, 1957: Mount Arrowsmith (Vancouver Island) and Chilkat Pass, B r i t i s h Columbia Weight B i l l Gonads Total Prom . Specimen Less Total Nos-Place Date Number Sex Crop Crop Length T a i l Wing Foot Width t r i l Left Rt. +» cd M CQ rH CQ •H Ct3 A PH o +» H •H CQ a M CQ o u u < u CD • > o o • +a cd 9 / 7/57 WT21-•57 M 3 .5 322.8 31.8 10.2 18.1 7.5 .79 1.02 9 / 3 /57 WT19-•57 P 15.1 315.4- 29.8 9.4 17.6 7.1 .81 1.04 9 / 7/57 WT22-•57 F 5.5 330.0 30.5 9.4 17.3 7.5 .77 .93 9/29/57 WTA3-•57 M 11.0 386.8 19 .7 19.2 7.9 .77 1.04 9/29/57 WTA5-•57 M 19.0 393.4 11.4 18.9 7.8 .78 1.11 9/29/57 WTA1-•57 F 30.0 298.6 11.7 18.1 7.6 9/29/57 WTA2-•57 F 8.0 396.0 10.8 18.1 9/29/57 WTA4-•57 F 21.0 379.9 10.8 19.0 7.9 .78 1.04 9/29/57 WTA6-•57 F 19.0 400.5 11.0 18.6 7.6 .79 1.06 .42 Small f o l l i c l e s Table XVII. Rock ptarmigan, 1956-1958 Weight B i l l Gonads  Speci- Total Prom men Less Total Nos-Place Date Number Sex Crop Crop Length T a i l Wing Poot Width t r i l Left Right Chilkat 5/ 3/57 R 1-•57 M 7.8 435.4 35.2 Chilkat 5/ 3/57 R2a-•57 M 10.3 403.8 35.9 Chilkat 5/17/57 R 3-•57 M 13.0 418.1 Eagle 5/16/56 R 1-•36 M «? 386.5 33.0 Creek 5/19/56 R 3-•56 M 22.6 453.4 33.0 Chilkat 5/29/57 R 5-•57 M 5.6 411.4 33.7 A t l i n 6/ 9/58 R 1-•58 M ? 378.1 35.2 A t l i n 6/ 9/58 R 2-•58 M- 9.7 400.0 34.6 Chilkat 6/15/57 R 7-•57 M 6.5 400.9 34.6 Chilkat 7/ 4/57 R 3-•58 M 9.6 441.9 35.0 Chilkat 7/15/57 R 8-•57 M 7.1 402.4 33.7 Chilkat 7/15/57 R 9-•57 M 6.9 401.6 37.1 Chilkat 7/15/57 R10-•57 M 10.1 411.9 35.7 Chilkat 5/ 3/57 R2b-•57 P 16.3 406.2 34.6 Chilkat 5/17/57 R 4-•57 P 6.0 394.0 Eagle 5/16/56 R 2-•56 P - 319.7 29.8 Creek 5/19/56 R 4-•56 P — 460.2 31.7 Chilkat 5/29/57 R 6-•57 P 5.8 419.0 33.3 Chilkat 7/ V58 R 8-•58 P 8.0 346.9 33.3 Susitna Alaska 7/ 8/58 R10-•58 P - 406.0 34.3 Eagle Creek 7/25/58 R l l -•58 P 12.3 346.5 34.9 12.1 20.0 7.6 .78 1.02 1.39 1.46 11.7 19.4 7.3 .70 1.03 1.15 1.11 11.4 19.0 .75 1.07 10.2 19.0 7.0 .80 1.05 1.90x1.301.50x. 80 10.2 18.6 7.6 .83 1.14 1.43 x.97 1.40 x.95 11.7 19.1 7.9 .75 .91 1.51 1.46 12.7 19.9 7.0 .74 1.06 1.08x.90 1.17x.89 12.1 19.4 6.7 .78 1.08 1.18x.99 1.23x.99 11.7 19.7 7.8 .78 1.03 1.23 1.10 12.4 19.6 7.2 .79 1.04 .89x.59 .91x.57 11.4 18.7 7.8 .75 .91 12.4 19.4 7.3 .75 1.02 .62 .64 12.1 20.0 7.9 .78 1.04 .57 .57 11.1 18.1 7.6 .76 .99 L i t t l e level. .69 .96 9.5 17.8 7.0 .68 ..92 .65,.60 10.2 18.7 7.0 .68 .96 2.18,2.00 10.5 18.7 8.3 .76 .88 9.5 18.4 7.9 .75 1.02 10.8 19.0 7.3 .76 1.08 Regressed 9.5 18.1 6.7 .75 .95 APPENDIX III PARASITES OF PTARMIGAN Author Babero (1953) Holt (1952) Babero (1953) Babero (1953) Huus (1928) PARASITES Parasite Species Ascaris compar  Triehostrongylus tenuis  Triehostrongylus sp. Capillaria sp. Mic r o f i l a r i a lagopodis Ascaridia compar  Oapillaria l o n g i c o l l i s Same two as above Trematoda: Leucoehloridium variae  Brachylaima fuscata Cestoda: Haploparaxis g a l l i  Rhabdometra n u l l i c o l i s  R a i l l i e t i n a urogalli Davainea proglottina R a i l l i e t i n a urogalli  Wienlandia microps OP PTARMIGAN Frequency Ptarmigan Location Percent of Examined Parasite lagopus (191) Alaska 8.9 mutus (4-5) Alaska 2.1 leucurus (56) Alaska 0.3 Alaska 0.3 lagopus (42) Alaska 45.2 lagopus (469) Norway 45.0 lagopus (117) Finland 0.0 a l l species (292) Alaska 2.7 (1-214/bird) a l l species Alaska 11.3 (1-265/bird) a l l species (292) Alaska 5.5 a l l species Alaska 0.3 a l l species Alaska 3.1 a l l species Alaska 2.7 lagopus (517) lagopus Norway Norway 11.0 11.6 T T -, . / , Q C - 0 x R a i l l i e t i n a urogalli X I O J . X uy?^/ Wienlandia microps Rausch (1951) Haploparaxis g a l l i , sp. nov. Coccidia: Spirochaeta lagopodis Allen, E.A. (1933) Brinkmann (1927) Eimeria avium Holt (1952) Levine (1953) Allen (1934) Eimeria avium E. brinkmanni E. fanthami, sp. nov, E. "bonasae, sp. nov. Hansen et a l . (19551 E. brinkmanni E. fanthami Allen and Leuoooytocoon Levine (1935) Hartmann et a l . (1937) Aspergillus: Aspergillus fumigatus lagopus (192) Norway 14.9 mutus (1) Alaska lagopus (1) Quebec lagopus (112 chicks, Norway 193 adults) 75.0 50.0 lagopus (168) Norway 26.8 mutus (6) mutus N.W.T., Can. 16.6 16.6 lagopus mutus (1) mutus (1) Alaska, Labrador N.W.T., Can. Comparatively few lagopus (34) Manitoba 11.8 lagopus Norway APPENDIX IV NEST AND BROOD DATA 225 Table XVIII. White-tailed ptarmigan: incomplete clutches Location Date Pound Remarks Source Calculated Hatching Date San Juan Mts., Colorado (37°N.t 107°W.) 7/15 5 or 6 fresh eggs i n nest Sclater (1912) 8/6 Mt. St. Helens, Wash. (4-6°N., 122°W.) 6/10/4-1 4- eggs Jewett et a l . (1953) 7/3 Mt. Cheam, Hope, B.C. (49°10'N., 121°4-0'W.) 5/11/89 Pemale with eggs i n oviduct Munro & Cowan (194-9) 6/8 Mt. Tekarra, Jasper Natl. Park, Alberta (52°50»N., 117°55'W.) 6/28/4-4-Pemale with egg i n ovi-duct Cowan (1955) 7/25 •Wherever necessary to calculate the approximate hatching date, an incubation period of 21 days was assumed for each species. The f u l l clutch was considered to be 6 eggs for leucurus, 7 for mutus, and 9 for lagopus. 226 TABLE XIX. White-tailed ptarmigan: complete clutches Location Date Pound Remarks Calculated Source Hatching Date Colorado Colorado 6/19-7/15 14- nests Bent (193.2) Bent (1932) Chicago Lakes, Colorado 6/19 Chicago Lakes, Colorado 6/28 4- eggs 8 eggs Sclater (1912) Sclater (1912) Mt. St. Helens, Wash. (4-6°N., 122°W.) 6/20/34- 5 eggs Jewett et a l . T1953) Mt. Rainier, Wash. (4-6o50'N., 121°50'W.) 7/10/19 5 eggs half incu-bated Jewett et a l . T1953) 7/21 Atl i n , B.C. (59°4-5'N., 133°25'W.) 6/15/34-Munro (194-7) 227 Table XX. White-tailed ptarmigan: broods Location Date Pound Remarks i Source Calculated Hatching Date Southern Colorado 7/1-18 chicks a few hours old Bendire (1892) 7/1-7/18 Gunnison Co., Colorado (38°30'N.. 106°30'W.) 7/8/02 2 days old Bent (193-2) 7/6 Same as above 7/11/27 1 day old Bent (1932) 7/10 McDonald Peak, Montana (4-7° 30'N., 114°W.) 8/1-44 4 young, 2/3 grown Wright & Conaway (1950) Before 7/1 Manning Park, B.C. (49°N., 121°45'W.) 8/8/58 7 young Present study About 7/1 Waterton Park, Alberta (49°N., 104°W.) 8/28/58 Over one month Plook, pers. comm. About 6/25 Lorna Lake, B.C. (51°10'N., 123°10'W.) 8/4/58 4 chicks, about 1 month Present study About 7/4 Same as above 8/4/58 2 chicks, 10 days old (renest?) Present study 7/25 Bow Summit, Banff Natl. Park, Alba. (51°45'N., 116°30'W.) 7/6/39 Newly hatched Clarke & Cowan (1945) 7/5 Maccarrib Pass, Jasper Natl. Park, Alberta (52°40'N., 118o10'W.) 7/31 Small chicks Clarke & Cowan (1945) July 228 Table XX—Continued Location Date Pound Remarks i Source Calculated Hatching Date Cairn Pass, Jasper Natl. Park Alta. (52°40'N., 118°10'¥.) 7/15/44 small chicks Clarke & Cowan (1945) Early July Same as above 8/3/43 small chicks Clarke & Cowan (1945) Mid- or iLate July Southesh Pass, Jasper Natl. Pk. Alberta (52°45'N. 117°1G'¥.) 7/19/44 small chicks Clarke & Cowan (1945) Early July L i t t l e Heaven Summit, Jasper Natl. Park, Alta. (52°45»N., 117°W) 8/16/43 small chicks Clarke & Cowan (1945) Late July Rocher Deboule, B.C. (55°05'N., 127°35'W.) 7/21/44 6 chicks, large Munro (1947) Late June or early July Nine-Mile Mtn., B.C. (55°20'N., 127°30'¥.) 7/25/22 3 broods; 2, 13, 12 chicks Sivarth (1924) Doch-da-on Creek, B.C. (58°N., 130°¥.) 7/11/19 3 chicks (10 or 11 days old) Munro & Cowan (1947) July 1 Same as above 7/11/19 7-8 chicks, no age given Swarth (1922) Early July Chilkat Pass, B.C. (59°50'N., 136°20'¥.) 6/29/57 1 chick (incom-plete count) 1 day old Present study June 28 Same as above 7/15/57 7 chicks, 10 days old Present study July 5 229 Table XX—Continued Date Calculated Location Pound Remarks Source Hatching Date Chilkat Pass, 6 chicks, B.C. (59°50»N., 136°20»W.) 7/31/57 over one month Present study Late June Same as above 6/30/58 7 chicks, 8 days old Present study June Same as above 6/30/58 8 chicks, 12 days old Present study June Same as above 7/4/58 7 chicks, 15 days old Present study June Rose River, Yukon ( 6 1 ° N . , 133°W.) July 9 -18, 1944 10 downy chicks collected Rand: -(1944) July 17 230 Table XXI. Willow ptarmigan: incomplete clutches Location Date Found Remarks Calculated Source Hatching Date Severn River, Ont. (55°30'N., 88°W.) June 25 1 egg 9 (renest) Baird et al.(l875) July 24 Same as above July 10 10 eggs (renest?) Baird et a l . (1875) Aug. 1 Ghevak, Alaska (61°5'N., 167°W.) 6/20/46 6/21/46 2 eggs 7 eggs Walkin-shaw(l950) July 18 July 14 St. Michaels, Alas (63°30'N., 162°W.) . early June start laying Nelson (1887) early July Kotzebue Sound, Alaska (67°N., 164°W.) 6/3/98 11 eggs (12th i n hen) Grinnell (1900) June 25 Ft. Anderson, Anderson River, N.W.T. (69°N.t 128°W.) late May. early June start laying MacFarlane (1891) late June, early July Lucas Point, MacKenzie Delta, N.W.T. (69°N., 135°W.) 6/4/58 8 eggs (9th on June 6) Krebs, pers. comm. June 27 Banks Island, N.W.T. (72°N., 126°W.) 5 out of 7 late June 6- females had Manning June to 12, 1953 eggs i n ovi- et a l . mid-July duct (1956) Arctic Coast, Alaska (70°-72°N.) 6/14/53 eggs m oviduct Kessel et a l . TT953) early July Same as above 6/11/53 e g ? s i n oviduct Kessel et a l . T1953) early July 231 Table XXII. Willow ptarmigan: complete clutches Location Date Pound Remarks Source Calculated Hatching Date Gafftopsail, Newf. (49°N. 57°W.) 6/16/12 8 eggs Bent (1932) Tonquin Valley, Jasper Natl. Pk., Alta. (52°40'N., 118°15'W.) July, 1931 2 nests Cowan (1955) Porcher Island, B.C. (54°N., 130°30'W.) June or July, 1921 9 eggs Brooks (1923) Long Point, James Bay, Quebec "(54°45*N., 79° 45'W.) 7/1/50 9 eggs Manning and Mac-Pherson (1952) Pt. George, James Bay, Quebec (53° 50'N., 79°45'W.) 6/23/96 13 eggs Manning and Mac-Pherson (1952) Bri s t o l Bay, Alas. (58°N, 158°W.) 5/29/30 10 eggs, fresh Hurley (1932) June 18-20 Br i s t o l Bay, A^as. (58°N., 158°W/) 6/4/30 13 eggs, i n -eub. advanced Hurley (1932) Late June Glacier Bay, Alas. (59°N., 136°W.) June 13 Nesting (com-plete clut-ches?) Bailey (1927) O'Donnell Creek, Atlin, B.C. (59°30'N., 133°15'W.) 6/26/14 Anderson (1915) Kodiak Is., Alas. (57°N., 157°W.) 6/25/11 11 eggs Bent (1932) Kuskokwim Delta, Alaska (60°N., 163°W.) 6/4/55 10 eggs William-son (1957) 232 Table XXII—Continued Location Late Found Remarks Calcu-lated Source Hatch. Late Johnson River, Alaska (60°47'N., 161°41»W.) 10 eggs (2 nests) Walkin-June 9- 9 eggs (1 nest) shaw & 12, 1946 10 eggs (2 nests) Staphlet (1949) St. Michaels, Alas. Home, Alaska (64°30'N.. 165°30'W.) Yukon Delta, Alas Wales, Alaska (65°40'N., 168°W.) Selawik, Alaska (66°40'N, 160°W.) June 6-10 ht. of incu-bation Brendt (1943) 6/8/14 Bent .(1932) 6/21/21 H i l l (1922) 6/14/14 9 eggs Bent (1932) 6/16/14 Bent (1932) 6/3/22 11 eggs 6/17/22 13 eggs 7/1/24 7/2/24 11 eggs 10 eggs Bailey (1948) 6/25/24 10 eggs 6/13/55 8 eggs 6/21/55 6/22/55 7 eggs 8 eggs (4 nests) Shepherd, pers. comm. 6/23/55 8 eggs 6/23/55 10 eggs ( a l l of above incubated) Late June 233 Table XXII—Continued Location Date Found Remarks Source Calcu-lated Hatch. Date Kotzebue Sound, Alaska (67°N., 164°W.) 6/17/98 13 eggs Grinnell (1900) MacKenzie Delta, N.W.T. (68°30'N., 135°15'W.) 5/31/32 9 eggs (slightly-incubated) Porsild (1939) June 15 Lucas Point, MacKenzie Delta, N.W.T. (69°N., 135°W.) 6/6/58 6/22/58 6/15/58 9 eggs 10 eggs 11 eggs Krebs, pers. comm. Umiat, Alaska (69°15'N., 152°W.) 6/13/53 8 eggs Baldwin & Reed (1954) Arctic Coast, Alas. (70°-72°N.) 6/27/14 11 eggs Dixon (1927) Arctic Coast, Alas. (70°-72°N.) 7/18/53 5 eggs Kessel et a l . (1953) Kaolak River, Alas. (70°11'N.. 159°48'W.) 6/28/52 7 eggs Bee (1958) Meade River, Alas. (71°N., 156°W.) 6/15/32 8 eggs Bailey (1948) Banks Island, N.W.T. (72°N., 126°W.) 6/24/53 12 eggs Manning et a l . (1956) 234-Table XXII—Continued Summary of Bests of willow ptarmigan i n North America* [Bent (1932)] Area Number of Records Range of A l l Dates Range of $ Records Northern Alaska 68 May 25 - July 10 June 6-25 Arctic Canada 37 June 2 - July 7 June 10-20 Labrador 18 June 1-30 June 6-23 Southern Alaska and B r i t i s h Columbia 3 June 25, June 26, May 28 Newfoundland 11 May 12 - June 30 June 8-12 No indication of clutch size or incubation stage given. Sources not stated. 235 Table XXIII. Willow ptarmigan: broods Location Late Found Remarks Source Calcu-lated Hatch. Date Newfoundland (49°N., 58°W.) Same as above Same as above June 6/31/38 6/26/4-2 many broods seen 10-12 days (4- broods) Peters and Bur-less than 10 /nSinS days (7 chicks) u y 5 x ; June 6/20 6/17-24-Lorna Lake, B.C. (51°10'N., 123°10'W.) 8/5/58 6 broods Present 6/25-study 7/5 Long Point, James Bay, Quebec (54-° 4-5'N., 79°4-5'W.) 7/4-/50 Same as above 7/13/50 Same as above 7/18/50 6 chicks, 2 days old 6 days old 12-20 days old (8 chicks) Manning and Mac-Pherson (1952) 7/2 7/7 Early July Bush Lake, east side 7/5-9/44- several James Bay, Quebec broods Manning Late (194-6) June or early July Gregory Lake, Quebec (60°N., 76°W.) 7/27 19 broods Eklund (1957) July Egigik River, Alas. (58°15'N., 157°W.) 6/24-/56 7 chicks, 1 or 2 days Krebs, pers. comm. June 23 Labrador Peninsula, 12 downy (59°N., 65°W.) 6/29/28 young Lewis (1928) 6/25-28 O'Donnell Creek, Atl i n , B.C. (59° 31'N., 133°15'W.) 6/26/14-downy young Ander-son (1915) 6/21-25 236 Table XXIII—Continued Calcu-lated Location Date Remarks Source Hatch. Found Date Kenai Mountains, Alaska (60°N., 150°W.) 7/10/01 7/14/01 7/17/01 Chapman (1902) Prior to mid-July Yakutat Bay, Alas. (60°N.t 139°30*W.) 7/12/38 downy Shortt (1939) July 7-11 Windy River, 7/28/47 Nueltin Lake, N.W.T. (60°N., 100°W.) 7/8/48 6 chicks, 12 days old newly hatched Harper (1953) July 16 July 7 Chilkat Pass, B.C. (59°50'N., 136° 20»W.) See tabula-tion at end of this table Present study Johnson River, Alas. (60°47'N., 161° 41«W.) 6/18/46 1 day old Walkin-shaw & Stophlet 6/17 (1949) Rose River, Yukon 6/11-(6l°N., 131°W.) 7/19/44 many broods Land (1944) early June to early July Hooper Bay, Alaska (61°30'N., 166°W.) June 21 Hooper Bay, Alaska (6l°30'N., 166°W.) July 6 f i r s t downy chicks seen f i r s t f l y i n g young seen Brandt (1943) Brandt (1943) June 20 late June Paxson, Alaska (63°10'N.. 146°20'W.) about 8 chicks,Present T -, 7 7/11/58 4-5 days study o u l y ' Mt. McKinley Natl Park, Alaska (63°30'N., 149°30'W.) 6/15/26 6/23/26 8 chicks, 1 day old 11-12 days old Dixon (1927) 6/14- , 6/11-12 237 Table XXIII—Continued Calcu-Location Date Remarks Source lated Pound Hatch. Date Lake Minchumina, Alaska (64°N., 152°W.) 6/23/12 Dixon (1920) June Yukon Delta, Alas. 6/23/14 1 day old Bent (1932) 6/22 Wales, Alaska (65°40'N., 168°W.) 7/10/22 downy chicks Bailey 1st wk. (1948) i n July Thelon Game Sanct., N.W.T. (65°N., 105°W.) 6/30/37 chicks hatched, i n nest Clarke (1940) 6/30 Eagle Creek, 9 T d l f i l d ^ Alaska (65°30'N., ± a a y 0 ± a Present 145°30,W.) 7/24/58 7 chicks, about study late 1 month old June 6/28/58 1 or 2 days 6/27 (3 broods) M a e l e n s ^ e l t a , ^ * * 6 / 2 5 N.W.T. (69°N., 1 a a y ° ± a comm. 135°W.) 6/27/58 10 chicks, 6/26 1 day old 6/29/58 5 chicks, 6/28 1 day old Umiat, Alaska (69°15'N., 152°W.) 7/11/53 7/12/53 7/24/53 more than 10 days old half grown late Baldwin June & Reed (1954) mid-June Nome, Alaska (65°30'N., 168°W.) 7/15/45 just hatched (several broods) H i l l 7/14 (1922) 238 TABLE XXIII—Continued Location Date Pound Remarks Source Calcu-lated Hatch. Date Kaslak River, Alaska (70°11'N., 159°58'W.) 7/12/51 7/17/51 7/23/51 fly i n g f l y i n g f l y i n g (7 chicks) (4 chicks) (10 chicks) Bee (1958) late June or early July Topagaruk, Alaska (70°34'N., 155° 48«W.) 7/5-10/ 1952 4- or 5 days old Bee (1958) July 1-5 Banks Island, N.W.T (72°N., 126°W.) * 7/15/52 3 days old Manning et a l . (1956) Arctic Slope, Alas. (70°-72°N.) 7/25/53 fly i n g Kessel et a l . (1953) Summary of nest and brood data (present study) Chilkat Pass, B r i t i s h Columbia Date Hatched, . 1957 Number of Broods Date Hatched, 1958 Number of Broods June 21 1 22 1 24 2 25 1 26 3 27 7 28 5 29 4 30 4 July 1 7 2 3 3 4 10 1 11 1 19 1 24 1 26 1 June 18 2 19 1 20 3 21 2 22 2 23 5 25 1 26 1 27 _1_ 18 47 239 Table XXIV. Rock ptarmigan: incomplete clutches Location Date Pound Remarks Source Calculated Hatching Date Krenitzen Islands, Aleutian Islands, Alaska (54-°N., 165°¥.) June 2 Female with large egg i n oviduct June 23-McGregor June 30 (1906) Aleutian Islands, early nests Alaska June begun Bent (1912) early July Southern Baffin 6/10/24-Island (64-°N., 68°¥.) 6/16/24-Pemale with shelled egg i n oviduct Sulton (1932) mid-July Angmagsalik, Green-land (65°N., 38°W.) 6/3/15 Female with shelled eggs Helms (1928) 1st half of July Angmagsalik, Green-land (65°N., 38°¥.) 6/17/08 6 eggs i n nest Helms (1928) 1st half of July Kotzebue Sound, Alaska (67°N., 164-°¥.) 5/27/98 nests begun Grinnell late (1900) June 240 Table XXV. Rock ptarmigan: complete clutches Location Date Pound Remarks Source Calcu-lated Hatch, Date Hokkaido, Japan (43°N., 143°E.) Tanapa and Adak Islands, Alaska (51°47'N., 177°W.) 6/25/11 6/26/11 Clutch 5-12; nests May-July-Austin & Kuroda (1953) 8 fresh eggs (2 nests); 9 eggs (1 nest) Bent (1912) 7 fresh eggs (2 nests) mid-July Atka Island, Alas. ^ / • z r i (52°N., 174°30'¥.) D / : > u 8 eggs Gabriel-son (1944) Krenitzen Islands, 7/6 Alaska (54°N., 165°W.) 7/12 6 eggs 6 eggs McGregor (1906) Kodiak Island, Alaska (57°N., 157°W.) 6/25/44 8 eggs, species Howell uncertain (1948) Beverly Lake, N.W.T. (64o40fN., 100°30»¥.) Iceland (64°N., 19°¥.) 6/25/49 7 eggs 6/19/29 11 eggs (small embryos) Mowat & Lawrie (1955) Congreve , & Preme (1930) J u l y Angmagsalik, Greenland (65°N., 38°¥.) Eagle Creek, Alaska (65°30'N., 145°30'¥.) 6/15/05 7/9/05 6/13/56 6/2/56 6/7/56 6/25/56 9 eggs (large embryos) 9 eggs (large incubated) 7 eggs (half incubated) 5 eggs 7 eggs 5 eggs (renest?) Present study late June July 19 June 24 241 Table XXV-—Continued Location Date Pound i Remarks Source Calcu-lated Hatch. Date Wales Mt.", Wales, Alaska (65°40»N., 168°W.) 6/15-21/ 1922 5 clutches Bailey (1927) Nome, Alaska (65°30'N., 168°W.} 6/20/22 7 or 8 eggs Bent (1932) Mouth of Perry River, N.W.T. (67°40'N., 101°W.) 7/7/50 10 eggs Scott (1951) Bathurst Inlet, N.W.T. (67°N., 108°W.) 7/3/50 7 eggs McEwen (1957) Wilcox Head, West Greenland 7/3/34 6 eggs Dalgety (1936) Summary from Bent (1932) Area Number of Nests Range of A l l Dates Range of ft Nests Northern Alaska 15 May 28 - July 29 June 9 -July 1 Arctic Canada 23 June 3 - July 9 June 17 -28 Greenland 17 May 20 - July 6 June 16 -30 Labrador 12 June 11 - July 7 June 3 -20 Iceland 18 May 7 - July 21 May 20 - June 19 Aleutian Islands 7 June 10-26 Newfoundland 11 June 2-12 242 Table XXVI. Rock ptarmigan: broods location Date Pound Remarks Source Calcu-lated Hatch. Date Nine-mile Mt., B.C. (55°20'N., 127°30'W.) 7/25/22 3-12 chicks (10 broods) less than 10 days old Swarth 7/15-(1922) 7/24 Chilkat Pass,B.C. (59°50'N.. 136°20'¥.) 7/4/58 6 chicks, 7 days old Present study 6/27 Cape Chidley, Labrador (60°15'N., 65°W.) Last of July 8/6 nearly f u l l -grown 6 chicks, 90-110 gms, mid-June Gross (1937) early July Igiak Bay, Alaska 7/11/24 about 2 wks. old Bent late (1932) June Nunivak Island, Alaska (60°N., 167°W.) 7/2 3 chicks. (just hatched) Swarth (1934) 7/1 Rose River, N.W.T. (6l°N., 131°W.) 6/25/44 6/25/44 8 chicks 4 chicks 6/14-26/ downy chicks 1944 collected Rand (1944) mid-June L i t t l e Susitna River, Alaska (6l°45'N.. 149°30'W.) 7/8/58 3 chicks, 15 days old Present study 6/23 Mt. McKinley Natl, Park, Alaska (63°30'N.. 149°30'W.) 6/28 9 chicks, just hatched Murie (1946) 6/27 24-3 Table XXVI—Continued Location Date Pound Remarks Source Calcu-lated Hatch. Date Chesterfield Inlet, N.W.T. (63°20'N., 91°W.) 7/14-20 peak of hatch Savile (1951) 7/14-20 Greenland (64°N., 51°30,W.) 7/5 1 day old Nicholson (1930) 7/4 Iceland (64°N., 19°W.) 7/21 7/29 5 chicks (lO-l l days old) 11 chicks (lO-l l days old) Scott & Pisher (1953) 7/10 7/17 Andrups Island, Greenland 7/25/34 newly hatched Dalgety (1936) 7/24 Eagle Creek, Alas (65°30'N.. 145°30,W.) See tabulation at end of this table Present study Same as above 6/22/51 7/14-20 I brood II broods (av. 7.3 young) DeLeon-ardis (1952) Porty-mile, Alas. (64°N., 141°W.) 7/10/51 6 broods, 4-8 chicks DeLeon-ardis (1952) Cape Dalton, Green-land (66°10'N., 35°30»W.) 7/10/32 8 chicks Degerb^l & Mjzfcl-Hansen (1935) Kangerdlugssuak, Greenland (66° 10'N., 35°30»W.) 7/10-20 6-8 chicks com. Scott & "fully-developed Pisher chickens" (1953) June 244 Table XXVI—Continued Location Date Pound Remarks Source Calcu-lated Hatch. Date Back River, N.W.T (66°N., 105°W.~) 8/3/54-7/15/54-9 chicks, 1/3 grown Brecken-ridge few days old (1955) mid-- July early July Mouth of Perry-River, N.W.T. (67°4-0'N., 101°W.) 7/26/4-9 7/31/4-9 more than 9 days more than 9 days Scott (1951) mid-July Bathurst Inlet, N.W.T. (67°N., 108°W.) 7/13/50 5 chicks just hatched McEwen (1957) 7/12 Ahlasuruk River, Alaska (68°20'N., 157°W.) 6/25/53 chicks few days old Congreve & Preme (1930) 6/23 Wahoo Lake, Alas. (69°8'N., 14-6°58'W.) 7/6/52 7/18/52 few days about 30 days Bee (1958) early July 6/18 Sabine Island, Greenland (74-° 4-5'N., 19°W.) 7/10 few days Deich-mann (1909) early July Summary of nest and brood data (present Eagle Creek, Alaska 1956 study) Date Hatched No. of Broods Date Hatched No. of Broods May 26-28 1 3 June 21 . 22 1 3 2 1 15 1 1 15-24- .. ?fi 3 1 16 2 27 1 18 1 28 1 19 2 July 1 1 20 10-20 ... 2 4-APPENDIX V BANDING DATA 246 Willow Ptarmigan Banded i n 1957, Recaptured i n 1958 Band Number 505-50402 505-50410 505-50411 505-50415 505-50433 505-50452 505-50455 Banded as adult female on nest June 14, 1957. Recaptured June 20, 1958, with two-day-old chicks, 100 yards west of 1957 nest. Shot June 27, 1958, 150 yards from last observation. Banded as adult male June 28, 1957, mated to female No. 505-50401. Present on same t e r r i -tory, with unhanded female June 16-27, 1958. Banded as adult male July 1, 1957, was mated to female No. 50452 i n 1957 and 1958, and occupied essentially the same territory both years. Banded as adult female July 2, 1957, with chicks one-day-old. Recaptured June 23, 1958, with brood of chicks same age, about 300 yards from point of capture i n 1957. Banded as adult female July 9, 1957, with chicks about five days old. Recaptured same place on June 28, 1958, with brood of unknown age. Banded as adult female July 25, 1957, with chicks six days old. Recaptured June 22, 1958, with seven or eight one-day-old chicks 100 yards west of point of banding. Mated to male No. 505-50411 both years. Banded as chick one month old on July 28, 1957, from brood of male No. 505-50410 and female No. 505-50401. Recaptured June 28, 1958, as adult female with five-day-old brood on adjacent territory, 250 yards south of point of banding and nest where i t hatched i n 1957-Seventy willow ptarmigan were banded from June 13 to August 9, 1957. Of those birds, 27 were adult female, 20 were adult males and the remainder were chicks of undetermined sex. At Eagle Creek, Alaska, five adult female rock ptar-migan were banded i n 1956. None of those were shot or returned, 247 but an adult male and adult female willow ptarmigan banded the same season were shot i n October, 1956 close to the band-ing place. Those were the only willow ptarmigan banded that year. 

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