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The effect of orchard spraying on pheasants in the Okanagan valley, with observations on bird-life in… Benson, Walter Arthur 1950

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L e 5/67 l i t e fry THE EFFECT OF ORCHARD SPRAYING OH PHEASANTS IN THE OKANAGAN VALLEY WITH OBSERVATIONS ON BIRD-LIFE IN ORCHARD AREAS' by W . Arthur Benson A Thesis Submitted i n P a r t i a l Fulfilment of The Requirements f o r the Degree of Master of Arts In the Department of Zoology The University of B r i t i s h Columbia A p r i l , 1950 T H E E F F E C T O F O R C H A R D S P R A Y I N G OH P H E A S A N T S I N T H E O K A N A G A N V A L L E Y W I T H O B S E R V A T I O N S O N B I R D - L I F E I N O R C H A R D A R E A S ' b y W. A r t h u r B e n s ; o n A B S T R A C T A r e v i e w o f t h e c u r r e n t l i t e r a t u r e o n D D T a n d r e p o r t s f r o m s p o r t s m e n a n d g r o w e r s i n d i c a t e d t h a t t h f i c o n c e n t r a t i o n s : o f D D T u s e d i n t h e O k a n a g a n V a l l e y w e r e g r e a t e r t h a n t h o s e e x p e r i m e n t e d w i t h p r e v i o u s l y . F u r t h e r , t h a t m a n y o t h e r i n s e c t i c i d e s p o s s i b l y d e t r i m e n t a l t o w i l d l i f e w e r e i n u s e i n t h e O k a n a g a n * A r e c e n t d e c l i n e i n p h e a s a n t p o p u l a t i o n s w a s a t t r i b u t e d t o o r c h a r d s p r a y i n g b y m a n y i n t e r e s t e d p e r s o n s * T h e p r e s e n t i n v e s t i g a t i o n i s o f a p r e l i m i n a r y n a t u r e a n d s e t o u t t o d e t e r m i n e : 1. T h e e f f e c t o f o r c h a r d s p r a y i n g o n p h e a s a n t s * T h i s w a s d o n e b y m e a n s o f c o n t r o l l e d e x p e r i m e n t s w h e r e i n p h e a s a n t s w e r e p l a c e d i n o r c h a r d s d u r i n g t h e n o r m a l c o u r s e o f o r c h a r d s p r a y i n g . 2 . T h e r e s i d u a l e f f e c t o f t o x i c s p r a y m a t e r i a l s . T h i s w a s d o n e b y s u b j e c t i n g p h e a s a n t s t o a p e r i o d o f s t a r v a t i o n s o m e t i m e a f t e r t h e y h a d b e e n s p r a y e d . 3. T h e e f f e c t o f o r c h a r d s p r a y i n g o n w i l d - l i f e o t h e r 2 e than pheasants. This was done mainly by f i e l d observations. 4. Whether or not the recent pheasant decline was due to orchard spraying. This was also done mainly by f i e l d observations;. It was found that Parathion with DDT, Parathion, DDT, Hexafoss and Lindane were toxic to pheasants while Mono DN was apparently non-toxic. Inhalation exposures are probably more toxic than ingestion exposures and older birds are app-arently more susceptible to both;;exposure types than are young bi r d s . This 13 thought to be a r e f l e c t i o n of the feeding habits of the two age groupa. A residual e f f e c t was not observed for any of the in s e c t i c i d e s tested but the data was not conclusive. Robins, bluebirds and song sparrows are the avian species most affected by orchard spraying. Which sprays are the most toxic i s not known at present although Parathion apparently doars not harm robins.- The mourning dove and C a l i f o r n i a q u a i l are apparently not affected by orchard spraying. Chemical analyses by the t o t a l chlorine method do not furnish adequate evidence of death from toxic sprays: at the present time. Too many variables are evident that possibly a l t e r the toxic e f f e c t of the s.pray material. The recent pheasant decline did not r e s u l t from orchard spraying although this practice may have aided decline* The reason for the decline i s not known, many theories have been advanced but they are not wholly v a l i d . The conclusion reached i s that the pheasant population c h a r a c t e r i s t i c i s not f l a t but shows fluctuations which may l a t e r prove to be c y c l i c when more information i s av a i l a b l e . Several suggestions for future studies, concerning orchard spraying, are made. It i s hoped that the b i o l o g i s t s w i l l keep pace with i n s e c t i c i d e development a TABLE OF CONTENTS PAGE Introduction 1 Equipment, Methods and Sprays 4 Acknowledgments 8 Methods 10 Pens.... • 10 Spraying and Care of Birds 10 General • «11 Stock *....; .12 Experiments 15 Experiment I 16 Experiment II .21 Experiment III •......«.. 22 Experiment IV 23 Experiment V ....24 Experiment VI »25 Experiment VII .27 Experiment VIII 28 Experiment IX .....29 Experiment X .30 Exper iment XI 31 Experiment XII » 33 Experiment XIII » 34 Controls 36 Experiment XIV 38 F i e l d Observations on the Ef f e c t s of Orchard Spraying on W i l d l i f e Other than Pheasants 42 TABLE OF CONTENTS (continued) ....... . . _ PAGE E f f e c t of Parathion on Mourning Doves 42 Cedar Waxwings 43 Ef f e c t of spray on Domestic Chickens .....43 Ef f e c t of spray on Bluebirds .'..•.44 Ef f e c t of spray on Robins ;..46 E f f e c t of spray on Sparrows 49 E f f e c t of spray on Quail ..49 General Discussion 50 Discussion of Chemical Analyses as a r e l i a b l e Source of evidence of death from toxi© sprays ..54 The Influence of Orchard Spraying and Other Factors on Pheasant Populations 62 Toxic E f f e c t 62 Habitat Preference ...» .64 Orchard Spraying as a Cause of Population Decline .68 The Population Decline and I t s Causes ...........70 Summary and Conclusions ^................. 75 Suggestions for Further Study • .82 Literature Cited • .84 THE EFFECT OF ORCHARD SPRAYING ON PHEASANTS IN THE OKANAGAN VALLEY WITH OBSERVATIONS ON BIRD-LIFE IN ORCHARD AREAS INTRODUCTION The literature dealing with the effect of DDT on birds Is f a i r l y large and extremely variable. Mitchell (18) sprayed DDT on bird nests with a hand atomizer. He sprayed the equi-valent of 5 lbs./acre and foundthat there was no apparent effect upon the hatching of the eggs; or development of the young* Similar results were obtained by Hope (11) who sprayed DDT mixed with mentor o i l and cyclohexanone on the eggs and nests of several birds* He found also that adult birds were not affected by the residue on the eggs* Several birds were dusted with DDT mixtures and no effects were found except for one olive-backed thrush which, i t is believed, died as a result of undernourishment* Erickson (9) reports no s i g n i f i -cant effect on bird populations after applying DDT at the rate of 0.1 lbs ../acre. Stewart et a l (25) sprayed 2 lbs* of DDT per acre and found l i t t l e or no effect on birds, with the possible exception of the redstart (Setophaga r u t i c i l l a ) . Couch (6) used a 5% solution of DDT in #2 fuel o i l j applied 2. at the rate of 0.2 - 0«5 lb» of DDT per acre and found that insects were greatly affected as were some cold-blooded ver-tebrates* An accompanying shift in the bird populations to areas where more food was available was noted. He points out that while no obvious harm is caused to birds and mammals, with the concentrations used, there may be serious indirect effects resulting from the upset of the food chains in the area sprayed• Kendeigh (13) applied DDT at the rate of 1 lb. per acre and found a negligible immediate mortality of birds. This concentration did not affect the size of the total breeding population nor success in raising young* Nelson and Surber (20) bring up an anomalous situation when they show that mortality of birds and mammals was not evident when DDT was applied in concentrations up to 3 lbs;•/acre yet a mor-t a l i t y of at least 25% occurred in a group of nestlings?when fed with insects k i l l e d by a 1 lb./acre concentration of DDT applied as spray* The work of Hotchkiss and Pough (12) shows •a conspicuous reduction in the breeding population of birds when DDT is applied at the rate of 5 lbs./acre. Bobbins and Btwart (21) and Adams et a l (l) show results similar to those of Hotchkiss and Pough. Adams and his co-workers also applied r birds spray at the rate of 7t lbs./acre and found several dead and A dying birds with tremors; and"incoordination. When they applied DDT at the rate of 5 lbs./acre, affected birds were found but two families of ruffed grouse survived two sprayings. Spiers. (24) found that spraying 4 lbs. of DDT per acre had no s i g n i f i -3 cant e f f e c t on the b i r d population of the for e s t but that repeated sprayings amounting to 10 l b s . of DDT per acre had a marked e f f e c t i n reducing the b i r d population* Myrtle and bay-breasted warblers;, chipping and white-throated sparrows were most affected* This brief review of the l i t e r a t u r e revealed that the con-centrations used i n other studies were much smaller than those used i n the Qkanagan V a l l e y . Considering this and the f a c t that many reports from the Okanagan t o l d of pheasants dying as a r e s u l t of spraying, i t was decided to conduct an investigation into the effects of orchard spraying on pheasants. As i t i s impossible to ignore wild species i n the orchards, It was also decided to include f i e l d observations on these species. The present paper i s the r e s u l t of a preliminary study to provide a basis for future research, the ultimata aim of which should be to advance p a r a l l e l with i n s e c t i c i d e development* The purpose of this investigation was f i r s t * to determine the e f f e c t of orchard spraying* This was to be done by design-ing controlled experiments whereby various i n s e c t i c i d e s would be tested during the normal course of orchard spraying. Second, to test the res i d u a l e f f e c t of the inse c t i c i d e s i n common use by subjecting birds which had been sprayed to adverse conditions. Third, to supplement experimental evidence with f i e l d observations on orchard w i l d l i f e . Fourhh, 4. to determine whether or not the slump i n the pheasant pop-ulation of the Okanagan could be due to the e f f e c t of orchard spraying*. The pheasant decline f i r s t became evident i n 1944 and reached i t s low ebb i n 1947 and 1948 when a closed season was enforced. Equipment, Methods and Sprayss The spray machines used intthe Okanagan Vall e y f a l l into four main categories; ( l ) Conventional sprayers - These machines cover three to f i v e acres per day and c a r e f u l operators achieve almost per-fe c t coverage. Coverage by the average grower i s 30 to 50% as high a deposit at the top of the tree as at the bottom. Two men operate the handguns and one man drives the t r a c t o r . The pressure used i s 350 - 650 p . s . i . , H.P. i s 5 - 25 and output i s from 5 - 20 gallons per minute* The machine with the o s c i l l a t i n g spray platform, used i n many of the experi-ments, i s a modified conventional machine. Although i t i s s l i g h t l y faster than handguns and may d i s t r i b u t e f i n e r part-i c l e s , i t s t i l l uses conventional rather than concentrate mixtures. Concentrate machines use more spray material i n a smaller tank than do conventional machines but cover a larger acreage i n the same time, hence the amount of i n s e c t i c i d e per acre i s approximately the same. (2) Speed sprayers, -Coverage i n this case i s equivalent to f a i r handgun spraying. Speed i s about 15 acres per day or double this when a "nurse" truck i s used* The crew consists of one man or two i f the "nurse* truck is used* , Pump pressure for these machines is about 20 p.s*i* and H.S. required is 100 - 110* These machines operate by discharging insecticide at conventional dilution into a high volume a i r stream which sprays to both sides simul-taneously* (3) Concentrate sprayers - Coverage in tree tops is better with these machines but they are otherwise similar to the speed sprayers. Their speed is about 15 acres per.day and they spray to one side only* The crew consists of one man* Pressure runs from 200 - 400 p * s . i . , H.P. is 10 - 20 and output per minute is 2 - 5 gallons* (4) Steam sprayers - These are actually concentrate sprayers that atomise the liquid insect-icide by means of a high velocity steam blast* These machines uti l i z e a flash boiler operated by fuel o i l and are equipped with two gasoline engines in addition* One of the gasoline engines operates a high volume, low velocity fan* Steam pressure is of the order of 100 p . s . i . and steam temperature i s 275 - 300 degrees^!)' The number of sprays per summer and the amount of insect-icide used per spray varies from orchard to orchard* From three to five sprays are usually applied during a summer depend-ing largely upon the grower in question and the abundance of the orchard pests. Certain concentrations are recommended for each d i s t r i c t by the Provincial and Dominion Agriculture Dep-artments* Some growers adhere to these recommendations closely but others, reasoning from a dubious mathematical basis, believe that i f the calendar recommendations are good then twice the amount w i l l be twice as good. Evidence of this is sometimes observed when one passes an orchard in which the trees are virtually leafless in the middle of the summer. Other growerB simply do not know what concentrations they are using per acre of orchard. Thus in work of this sort i t is imperative that one watch closely the poundage of insecticide used per spray tank and the number of tanks per acre as growers are often reluctant to admit that they have deviated from the c a l - ( endar specifications. , . .... The most common insecticides which were used.in this in-vestigation were DDT (dichloro-diphenyl-trichlorethane). Parathion (o,o-diethyl-o-p-nitrophenyl thiophosphate). Mono DU ( l oz. Monoethanolamine mixed with 5 oz. dinitrocyclohexylphenol), Hexafosa (Hexaethyl-tetriphosphate) and Lindane which is the trade name for benzene hexachloride with a 99$T gamma ratingo DDT was f i r s t synthesized in 1 8 7 4 by a German chemist named Zeidler and was not patented until 1 9 3 9 . During the war years- i t was used on a large scale for mosquitoes, f l i e s , , body l i c e and bedbugs. In 1 9 4 7 , the insecticide was used by f r u i t growers for the f i r s t time* It Is used in the Okanagan primarily to combat codling moth and for this purpose i t is formulated as a wettable powder containing 50$" of actual DDT. Spraying of this substance alone often leads to an increase . in the numbers of woolly aphis and orchard mitas,5/ the latter probably increasing when DDT k i l l s off i t s natural and efficient enemy,the black beetle (Stethorns)* Parathion is usually used along with DDT or shortly afterwards as i t e f f e c t i v e l y controls orchard mites and woolly aphis* Earathion i s also used f a i r l y extensively against pear p s y l l a . Benzene hexachloride i s used f o r pear p s y l l a and the use of the high gamma isomer w i l l probably become more widespread due to i t s decreased odour and greater t o x i c i t y * Mono DU i s used mainly, i n conjunction with DDT, to combat orchard mites* The dinitrocyclohexylphenol i s the poisonous element i n Mono DU» Hexafoss was used f a i r l y extensively i n 1947 and 1948 to control woolly aphis but i t s popularity declined considerably i n 1949 due to the b e l i e f that i t was dangerous to handle — which may or may not be true. 8. ACKN'OWLEDGMBHTS: The P r o v i n c i a l Game Commission i n cooperation with the Department of Zoology at the University of B r i t i s h Columbia sponsored this i n v e s t i g a t i o n . TO these groups I am indebted* I wish to express appreciation f o r the assistance given me by Dr. W.A. Clemens, ff.J.Spencer, Dr. WT.S. Hoar, Dr.J.R. Adams, Dr. P.A. Larkin and J.- Hatter a l l of the Department of Zoology at the University of B r i t i s h Columbia. I am p a r t i c u l a r l y g r a t e f u l to Dr. Ian HcTaggart Cowan, under whose d i r e c t i o n I worked, fo r the Invaluable aid given i n the f i e l d and while preparing t h i s manuscript. Special thanks are given to-my wife, Charlotte, who assisted me ably throughout the inves t i g a t i o n ; to Mr. Archie Blackie of Kelowna, a keen conservationist who often bolstered my morale and stimulated my thinking; to Mr. E.I. Pridham who supplied land f o r our camp s i t e , pens and equipment and other services too numerous to mention; to Mr. Bert Chichester fo r his cooperation i n spraying birds and his knowledge of the Okanagan Valley;, to the Dominion Entomological Laboratory at Summerland fo r aid i n spraying pheasants, p a r t i c u l a r l y to Mr-* J . Munro McArthur for chemical analyses and Dr. James Marshall for the information regarding spray machines* Mr. Joe McLaughlin and Mr* W.G. Snow are deserving of appreciation as i s the Summerland F i s h and Game Association ' 9 . f o r supplying the author with pheasant chicks. Thanks also to the Kelowna Rod and Gun Club for the contribution of an extra tent used for supplies;, and to the many people who aided by lending me broody hens; also to the growers and others who cooperated by informing me of t h e i r spraying pro-cedures and bringing i n affected b i r d s . 10b METHODS Pens: Light, movable pens were constructed to contain the birds used i n experimental and control groups. These pens were 10 f t . long-, 3 f t . wide and 3 f t . high. They were made of 1x3 lumber and 1 inch mesh stucco wire. A rearing coop, which l a t e r served as a shelter, was constructed on a plan similar to that used by the Wisconsin Conservation Department (28). The coops used i n the present study were rectangular rather than triangular. Spraying and care of birds: Experimental pens were placed i n the orchards between the trees. Spraying crews were t o l d to give no s p e c i a l attention to either the pans or the mixtures but to carry on as usual* Notes were then taken on mixtures used par tank and the number of acres sprayed with each tank. These data were than converted to pounds per acre. The control pens were placed at the edge of a l i t t l e used pasture where vegetation was nearly conparable to that found i n the orchards. The control area had hawthorns for shade rather than f r u i t trees and there was a greater amount of Chenepodium album with a correspondingly lesser amount of red clover than i n the orchard areas. 11 B i a i t d s s p r a y e d - w i t h s t e a m m i s t a n d t h e n m o v e d t o a c l e a r a r e a , w e r e b r o u g h t t o t h e c o n t r o l a r e a . A l l p e n s w e r e m o v e d w h e n e v e r n a t u r a l f o o d b e c a m e d e p l e t e d . N a t u r a l f o o d w a s s u p p l e m e n t e d b y w h e a t a n d m a s h i n b o t h t h e c o n t r o l a n d t h e e x p e r i m e n t a l g r o u p s . W h e a t w a s p u t i n t h e p e n s t h r o u g h o u t t h e l i f e o f t h e b i r d s a l t h o u g h i t w a s e a t e n m a i n l y b y t h e m o t h e r h e n w h i l e t h e p h e a s a n t s w e r e v e r y y o u n g . T u r k e y s t a r t i n g m a s h w a s r e p l a c e d b y p o u l t r y m a s h w h e n t h e b i r d s w e r e s e v e n w e e k s o l d . G e n e r a l : B i r d s w e r e d i a g n o s e d a s h a v i n g d i e d f r o m t h e e f f e c t s o f s p r a y i f t h e y s h o w e d c h a r a c t e r i s t i c s y m p t o m s o r i f n o o t h e r c a u s e o f d e a t h c o u l d b e f o u n d . P o s t - m o r t e m s w e r e d o n e p a i n -s t a k i n g l y o n a l l d e a d b i r d ' s r e g a r d l e s s o f t h e i r s o u r c e , t h e o n l y e x c e p t i o n s b e i n g s o m e p a s s e r i n e s w h i c h w e r e m u c h t o o d e c a y e d . D u r i n g t h e s t u d y a s c l o s e a c h e c k a s p o s s i b l e w a s k e p t o n t h e w i l d p o p u l a t i o n s o f p h e a s a n t s b o t h i n a n d o u t s i d e o f o r c h a r d a r e a a . O b s e r v a t i o n s i n n o n - o r c h a r d a r e a s w a r e a l w a y s c a r r i e d o u t f r o m 6 A . M . t o 8 A . M . o r f r o m 6 B » . M . t o 9 P . M . a s t h e s e h o u r s c o n s t i t u t e d t h e m o s t a c t i v e p e r i o d s f o r p h e a s -a n t s . O b s e r v a t i o n s i n o r c h a r d a r e a s w e r e d o n e t h r o u g h o u t m o s t o f e v e r y d a y b u t o n l y t h e h o u r s s p e n t d u r i n g t h e t i m e s s h o w n a b o v e w e r e t a b u l a t e d . T h u s , m a n y m o r e h o u r s w e r e s p e n t i n o b s e r v i n g i n o r c h a r d a r e a s t h a n i s s h o w n . I t w a s t h o u g h t 12* t h a t t h i s method was the bes t i n t h a t o ther hours c o u l d not be compared w i t h those of the a c t i v e p e r i o d s . Two s p a n i e l s were used f o r a l l census work and to f i n d dead b i r d s . F o r purposes of t h i s i n v e s t i g a t i o n , b i r d s found o n e - h a l f m i l e or more f rom the n e a r e s t o r c h a r d s were c o n s i d e r e d as b e i n g i n n o n - o r c h a r d a r e a s . T h i s c r i t e r i o n seems to agree w i t h Buss (3) who found l i t t l e or no movement beyond a q u a r t e r of a m i l e f o r w i l d b i r d s . L e o p o l d (15) l i s t s the d a i l y c r u i s i n r a d i u s as o n e - e i g h t h to o n e - h a l f m i l e and the y e a r l y r a d i u s as o n e - h a l f to one m i l e . S t o c k : Nine c h i c k s h a t c h e d under a bantam hen on May 30 were s p r a y e d w i t h P a r a t h i o n and DDT on June 4 . The eggs had been o b t a i n e d from w i l d n e s t s and two of them were from a dump n e s t c o n t a i n i n g seventeen q u a i l and three pheasant eggs . The three c h i c k s i n C o n t r o l #1, ha tched June 14 , were the s u r v i v o r s of 13 c h i c k s ha tched from eggs o b t a i n e d a t a pheas -ant farm i n the lower E r a s e r V a l l e y . The weather was v e r y C o l d a t the time of h a t c h i n g and f o r a week t h e r e a f t e r ; however no b i r d s were sprayed i n t h i s weak and the c o n t r o l s e r v e d f o r sprays begun on J u l y 4 . B i r d s hatched on June 19 were sprayed on J u l y 4 w i t h DDT i n the one i n s t a n c e and w i t h P a r a t h i o n and DDT i n the o t h e r . They came from a pheasant farm i n Kelowna where thay had been hatched i n an i n c u b a t o r . The g e n e r a l p r o g n o s i s of t h i s group 13. was poor. Many of the chicks could not he used because of abnormalities at hatching. Thirty percent of the birds were eliminated early due to twisted f e e t , fused leg j o i n t s and general frailty.-. The birds. -ussdy'fthen, were the survivors and best of the group. Pheasants hatched on July 10 made up control #2 as well as the groups sprayed with Mono DN, Parathion and DDT on July 14 and came from the Summerland Rod and Gun Glub. Those hatched on July 14 came from the same source and formed control #3, the group sprayed with Parathion on August 8 and the group sprayed, with DDT on the same date. A l l birds were hatched i n incubators and t h e i r prognosis was good. The birds sprayed on August 11 and August 18, were obtained through the Game Department from a pheasant farm i n the lower Praser Valley* These birds were 14 weeks old and hatched on or about May 5. The birds forming control #4 and those spray-ed with Hexafoss and Lindane were obtained from the same source and hatched on June 13. Bantam and New Hampshire hens were used to mother the chicks u n t i l they grew too large to be covered by the hen or u n t i l they l e f t her. This i n t e r v a l usually lasted u n t i l the chicks were about f i v e weeks old. The hen and chicks were kept free of ectoparasites by dusting with commercial preparations which did not contain any of the spray material to be tested. A l l birds used i n the study were of mixed stock composed o f Phasianus colchicus torquatus and P i c . mongolicus i n varying 14 degrees. The torquatus s t r a i n was most prevalent i n the group. Thus the s t r a i n s of the experimental b i r d s were s i m i l a r t o the w i l d b i r d s i n the area as described by 00wan ( ? ) • 15 EXEBRTMKNTS: t * 1 In a l l bat one case, the experimental birds were sprayed during the course of normal orchard routine or shortly there-after. That i s , the growers: would have sprayed the same insecticide in the same concentration whether experimental pens were in the;orchard or not* Experiment VIII was the only exception and in this case part of the orchard was sprayed for the sole benefit of the experiment. Ho pests, requiring Mono ISST for their control, were present in the orchard at this time* The trees were sprayed as i f to control an orchard pest. Spray was not directed at the pens containing the experimental birds. For each spray material two types of exposure exist: 1* Inhalation • spray material taken into the body by breathing contaminated air* 2» Ingestion - spray material taken into the body with contaminated food or water. The original plan was to subject pheasants to a spray involving both exposure types to determine whether or not the spray was toxic* If the material proved toxic i t was proposed that each exposure type be tested separately to determine which had the moat toxic effect* Spray machines which discharge a very fine mist, suitable for inhalation exposures, were seldom available at the right time however and this type of exposure was tried 16* for DDT and for Parathion only* Other machines, which dis-charged a limited amount of fine mist and a great deal of coarse fog (droplets) were readily available at most times* Consequently the following experiments are predominantly of the ingestion type or a combination of both exposure types* Experiment I - Inhalation and Ingestion (Table i ) ; Nine chicks, five days old, were exposed to contaminated food, water and air on June 4* Three of these chioks survived the f i r s t exposure and were sprayed again on July 4 in exactly the same manner* Spraying was accomplished with a modified conventional machine with six nozzles set on an oscillating table which was manipulated automatically* The spray applied was 15^ Parathion at 9 lbs./acre and 5'0g£ DDT at 18 lbs ./acre• The symptoms observed in this experiment follow in detail for they display, remarkably well, the characteristics which subsequently proved to be typical for DDT poisoning. June 4 - 7:55 A*Mo - trees and pen sprayed on one side 8:15 A . M * - trees and pen sprayed on the other side 8:26 A .Ma - bantam mother closing eyes and head la drooping 8:32 A . M . - one chick with head back, opening mouth and f a l l i n g ; also jerking head spasmodically, bubbles appear-ing when mouth is open 17* 8:43 A.Mo - a l l chicks under hen hut two -these two show spasmodic jerking of the head and opening of mouth together with staggering almost to the point of f a l l i n g 8:45 A»Mo » two chicks above close eyes and throw heads backwards, much like a robin drinking 8:57 A . M . - a l l chicks under hen and hen is preening excessively 9:03 A . M . - one chick sitting on ground with very dumpy appearance and gasping (chick A) - another with tremors is convulsing and foaming at the mouth (chick B) - others apparently normal but preening excessively chick A is now foaming 9:05 A . M . - chick B with extreme tremors and convulsions is now dead 9:15 A.'M* - chick A with violent tremors and occasional convulsions can no longer stand, a great effort to get onto i t s feet again only to f a l l 9:2.0 A . M . - chick A has even more violent tremors, gaping and convulsions -wings are at odd angles and appar-1 8 o ently out of control 9 : 2 5 A . M . - chick A with long spasms and now dead 9 : 3 5 A . M . - chick C with s l i g h t tremors and gaping 1 0 : 0 5 A . M . - chick G much the same and Ghick D with s l i g h t tremors 1 0 : 2 5 A . M o - chick G losing balance intermit-t e n t l y while chick D i s much the same or may hare picked up s l i g h t l y 1 1 : 1 0 A . M . -chick E with tremors and floppy wings,chick C has hard time standing and has increased tremors 1 1 : 2 0 A . M . - chick E with v i o l e n t tremors and floppy wings 1 : 0 0 P . M . - chick G" i s unable to stand, mouth gapes intermittently and severe tremors - a l l others i n poor shape 1 : 1 5 P . M . - chick C with a v i o l e n t burst of energy got to i t s f e e t , ran about four feet and then f e l l down, lay there with severe tremors and convulsions 4 : 3 0 P . M » - a l l chicks except G and D appear to be improving hut s t i l l show d i s i n t e r e s t - bantam mother clucks 1 9 o June 5 • June 7 -June 9 -June 1 0 - 8 : 0 0 A . M . 8 : 2 0 A o M « July 4 -July 1 9 -July 2 0 -July 2 3 -July 2 4 -excitedly but chicks do not respond chicks G and D are dead - a l l others appear normal chick E. had s l i g h t tremors a l l day two other chicks; and chick E a l l have s l i g h t tremors chick E i s now dead - another has v i o l e n t tremors and the remainder have s l i g h t to moderate tremors chick which had v i o l e n t tremors i s now dead sprayed again with the same con-centration as before another chick with tremors, gaping and convulsions above chick i s dead one chick with extreme tremors and convulsions while the smallest chick has s l i g h t tremors - one of these chicks was the largest of the whole group and the other was the smallest smallest chick with severe tremors and occasional l i g h t convulsions -other chick dead 20. A u g u s t 5 -A u g u s t 4 -- smallest and sole remaining chick has had violent tremors a l l day - the above (last) chick i s dead TABLE I 15$; Parathion at 9 lbs../acre and 50^ DDI - at 1 8 lbs./acre on pheasants and food Conventional machine with oscillating spray table Chicks Age . . When Date of Cause of. nos« sprayed death death. 1 5 days . June 4 June 4 spray ( A : ) ' 2 it- * B ' 3 Its n June 5 * ( e ) « 4 * » tt 5 tt & tt June 10 * 6 It n June 10 * 7 5&36 days June . 4 &. July 20 It: 3 July 4 8 * lb July 24 It 9 It August- 4 •Letters refer to chemical analyses, see Table XXII TABLE II 15$ Parathion at 7 £ lbs./acre and 50#. DDT at 15 lbs./acre on pheasants and food Conventional machine with oscillating spray table - spray in droplets (fine fog) Chicks nos«> Age, When Date of .de ath Cause of death i 2. 3 4 5 6 7 8 9 days July 4 July 5 spray i t it- i t t t 11; i t i t »: Mi i t i t t t i r » Ik * i t t * July 6 II: B tt: i t I t I t t t a n tfc Hi t t 18 [0 P 'Letters refer to chemical analyses, see Table XXII 21a The last three chicks mere 36 days old when they were exposed for the second time* They were moved several times, when food was depleted, to other areas in the original orchard, contaminated by the same sprays. There are two possible explanations for the death (after the second spraying) of these three birds which withstood one spraying* (l) That the birds were older and more suscep-tible to toxic materials* Possibly their food habits had changed sufficiently to cause death from a concentration they had withstood when they were younger and ate more animal material* (2) Possibly the late death of these three birds shows a residual or cumulative effect* It took a period of 16, 20 and 31 days respectively for the birds to die after the second spray* Presumably each bird retained a certain amount of the toxic material from the f i r s t spray and obtained a sufficient additional amount-from the second spray to exceed the individual threshold of tolerance. If they had not stored some of the f i r s t spray i t seems unlikely that they would succumb to the same concentration at a later date unless, of course, greater age and/or food habits, had changed suf-f i c i e n t l y to alter the toxic effect of the spray material* further work w i l l probably throw light on the correct solution* Experiment II - Inhalation and Ingestion (Table II)• Nine chicks, 15 days old, were exposed to contaminated food, water and air on July 4* The same machine as that used 22. i n Experiment I was used h e r e . F i f t e e n p e r c e n t P a r a t h i o n a t 7£ l b s . / a c r e and 50% DDT a t 15 l b s . / a c r e were a p p l i e d . A group of three c h i c k s from the same s t o c k and of the same age were not sprayed and served as a c o n t r o l (Table XTV)• Despite the l i g h t e r c o n c e n t r a t i o n i n t h i s experiment, the b i r d s d i e d more r a p i d l y than d i d those of Experiment I* T h i s d i s c r e p a n c y i s b e l i e v e d to be due to the f a c t t h a t these b i r d s were o l d e r and ate more vegetable matter than the pheasants of Experiment I . Experiment I I I - I n h a l a t i o n and I n g e s t i o n (Table I I I ) . Nine c h i c k , 15 days o l d ; t h e i r f o o d , water and to some extent t h e i r a i r , were sprayed w i t h 50%" DDT a t the r a t e of 18 l b s . / a c r e an J u l y 4. There was l e s s o p p o r t u n i t y f o r i n h a l a t i o n i n t h i s experiment as handguns were used to d i s c h a r g e spray and the m a t e r i a l was i n coarse d r o p l e t s * "Very l i t t l e f i n e m i s t i s a s s o c i a t e d w i t h t h i s spray method. The same c o n t r o l group as that of Experiment I I was used (Table X I V ) . Seven c h i c k s d i e d d u r i n g the f i r s t two days while two were ap p a r e n t l y u n a f f e c t e d . These c h i c k s d i e d more r a p i d l y than d i d the c h i c k s of Experiment IV although c o n c e n t r a t i o n s were the same. The b i r d s were olde r i n t h i s experiment and the type of exposure was d i f f e r e n t i n that b i r d s c o u l d i n h a l e some spray m a t e r i a l . 23. TABLE III jS'QgC DDT at 18 lbs./acre on Pheasants and food Conventional machine.with.handguns... spray in droplets (coarse fog) Chicks .Age. . . When. Date of Cause of nos • sprayed death death 1 15 days . July 4 July 4 spray (QJ* 2 tt 3 » tt July 5 4 tt » tt (T)* 5 » tt * (U)» 6 it It it »; ? Y ) * 7 «t tt * (W)' 8 n. tt Aug. 23 pecking 9 * tt •Letters refer to chemical analyses, see Table XXII* Experiment IV - Ingestion (Table IV). Food and water were sprayed with DDT on July 13 and nine chicks, four days old, were placed in a pen on this sprayed area on July 14. line chicks served as a control and were of the same age and stock (Table XV). Eight chicks were dead at the end of five days and the remaining chicks died nine days after exposure. In general, chicks in this experiment took longer to die than the majority of birds in Experiment III. 'This discrepancy is believed to be due to the fact that birds of Experiment III were older and were subjected to the Inhalation type of exposure. 24 o TABLE IV 50$" DDT at 1 8 lbs ./acre on food only . Conventional machine with handguns spray in droplets (coarse fog] " Chicks Age . When. .Date of Cause of noa • sprayed -death death 1 4 days. July 1 4 July 1 5 spray ( 1 ) 2 ' H i it * (a) 3 » it Duly 1 6 4 it » it 5 n July 1 7 6 * 7 » July 1 9 8 it it * 9 it t» J u l * 23 »Numbers refer to chemical analyses, see Table.XXII. Experiment V - Inhalation and Ingestion (Table V). Ten pheasant chicks, 14 weeks old, were exposed to food, water and air contaminated with 50^ DDT at the rate of 15 lbs. per acre* Spraying was carried out on August 11 with the modified conventional machine* Seven chicks from the same stock served as a control (Table XVII)* F i f t y percent of these birds died as a result of sprayingj with typical tremors, convulsions and gaping outlined in Experiment I.* Ten percent (one bird) 'ct&ed'.as a result of peeking and 40^ survived. These birds were older" than those of Experiments III and Tf hut judging from f i e l d observations and other experiments i t is thought unlikely that this factor waa the cause of reduced mortality<» Rather, the older birds in general, die more quickly than the younger birds* This differential mortality with respect to age is probably related 25. to differences in food habits of old and young birds* The concentration of DDT used in this experiment was lower than for Experiments III or IV and this is thought to be the factor causing a lower mortality* It is probable that 15 lbs./acre of 50% DDT Is close to the threshold of tolerance' for pheasants (i.e. 7 i lbs./acre of actual DDT) when exposure is mainly of the ingestion type. TABLE Y 50% DDT at 15 lbs ./acre on pheasants and food _ Conventional machine with oscillating spray table - spray in droplets (fine fog) . Chicks . Age When Date of. Cause of nos* sprayed death death 1 14 weeks . . .Aug* 11 Aug* 13 pecking 2 o Aug* 15 spray 3 it tt. Aug. 17/ 4 » tt » 5 tt tt tt * 6 it » Aug* 25 tt 7 tt tt survived 8 ». tt II 9 tt » «> 10 »_ ir Experiment VI a Inhalation (Table VI). Ten chicks were exposed to a very fine DDT steam mist, 5.0% at 10 lbs./acre, on August 8. These birds ware removed to a "clear* area as soon as the mist cleared and none of them ingested contaminated food or water. Ten control chicks, (Table XVI) of the same age and source were used in conjunction with this experiment. 26o A l l ten chicks subjected to this inhalation exposure of DDT succumbed within 24 hours* They exhibited the symptoms outlined in Experiment I* Tremors mare probably more severe in this case than in any of the other DDT experiments* These ten birds were younger than those of Experiment V and older than those of Experiments III and IV* It seems unlikely therefore that age difference was responsible for the sudden* high mortality in this group. The concentration used in this experiment was even less than the concentration in Experiment V which was believed to be close to the threshold of tolerance* The logical conclusion then, is that inhalation exposures are probably more toxic than ingestion exposures. TABLE VI 50% DDT at 10 lbs./acre on pheasants only . Steam sprayer, .spray in very fine particles (steam mist) '. .. Chicks . . Age.. . When Date of Cause, of nos* sprayed : death death 1 . 25 days. . Aug* 8 Aug* 8 . spray 2 tt tt tt tt 3 * Aug* 9 n 4 » tt. tt it 5 tt » tt 6 it «. it tt 7 ii w » n 8 tt it ti # 9 » it tt 10 n. tt! tt it 274 Experiment VII - Ingestion (Table V I I ) . Ten chicks, four days old, were exposed to contaminated food and water on July 14* The food and water had been sprayed on July 13 with Hono DN at the rate of 60 oz./acra* The o r i g i n a l intention of this experiment was to test Mono UN alone but i t was found afterwards that the area, (hence natural food al s o ) , had been sprayed on July 10 with DDT i n an unknown con-centration. The men who applied the spray thought the con-centration to be more than 15 lbs./acre. Nine chicks of the same age and stock served as a control (Table XV). A l l birds died with t y p i c a l tremors, gaping and convulsions* Time for t o t a l death was approximately four days longer than for Experiment IV where the chicks were the same age and the exposure type was the same * DDT i s known to be toxic and i t i s thought that mortality was due mainly to the unknown concentration of DDT. The d i f -ference i n time for tofcal death shown for Experiment IV and this experiment i s attributable to two things: 1* DDT had been sprayed four days p r i o r to the exper-iment, thus allowing time for dissipation.-2. DDT sprayed i n this experiment may have been applied at a l i g h t e r concentration than that of Experiment IVe ; 28 » TABLE VII Mono DN at 60 oz./acre and 50%" DDT in an unknown amount on food only Conventional machine with handguns, spray i n droplets (coarse fog) Chicks Age When Date of Cause of nos. sprayed death death 1 4 days July 14 July 15 spray 2. tt i t i t 3 tt « July 16 It: 4 i t tt tt It. 5 It; tt i t It: 6 It Hi July 20 tt 7 H; tt July 23 II 8 II It July 24 It: 9 tt It July 26 It 10 It II: July 27 a Experiment VIII - Inhalation and Ingestion (Table V I I I ) . Ten chicks, 15 weeks old, were exposed to contaminated food, water and a i r on August 18i A control group of seven chicks was not sprayed (Table XVII). Handguns were used to apply Mono DN at the rate of 60 oz»/acre. This experiment was designed to obtain more conclusive evidence on Mono DN than was obtained i n Experiment VII. A l l chicks survived the spraying for although two died, the cause of death was d e f i n i t e l y not spray (see Table V I I I ) . This experiment bears out the assumption made i n Exper-iment VII, that DDT and not Mono DN was the toxic substance. 29 o TABLE VIII Mono DTS at 60 oz./aere on pheasants and food Conventional machine with handguns, spray in droplets (coarse fog) m Chicks Age When Date of Cause of noso sprayed death death 1 15 weeks Aug. 18 Aug. 26 pecking 2 * * Aug. 28 broken neck 3 * * survived 4 * •* Cj It: II tt: „ g M tt tt 7 »„* «:  8 * " * - -9 «* » II Experiment IX » Ingestion (Table IX)« Ten chicks;, four days old, were exposed to contaminated food and water on July 14. The nine chicks of Control #2, (Table XV) were of the same age and stock. Handguns were used to spray 15% Parathion at the rate of 16 lbso/acre on food and water on July 13. Five chicks died from the effects of the insecticide over a period of 13 days. The other five birds died from mechanical causes, none of which could be attributed to effects of spray. A l l birds, including the mother hen, preened excessively during the experiment. Convulsions and gaping were observed before death but tremors were not seen at any time • Prom this experiment, i t may be stated that Parathion in some concentrations: is toxic to pheasants. From the symptoms 30b observed, i t seems possible that the toxic substance i s i n some way carried by the blood (excessive preening) and that the central nervous system i s secondarily affected (convulsions). .TABLE IX 15$ Parathion at 16 lbs./acre on food only Conventional machine with handguns, spray i n droplets (coarse fog) . Chicks; Age When Date of Cause of noso sprayed death death 1 .4 days July 14 July 16 crushed. 2. * * July 1? spray 3 '» * July 19 * 4 * * July 25 ,fc 5 '* * July 26 broken neck 6 * * July 2.7/ spray rj> tt It tt* tt 8 tt » July 30 choked 9- * * Aug. 2 crushed 10 2 2 Aug. 15 pecking Experiment X - Inhalation (Table X) • Ten chicks', 25 days old, were exposed to a steam mist of 15^ Parathion at the rate of 12 lba./acre, on August 8. The mist was very fine and as soon as tha a i r cleared the birds; were moved to an uncontaminated area. The control group was comprised of ten birds of the same age and stock (Table XVI). None of the birds i n t h i s experiment ingested contam-inated material. E i f t y percent of the birds i n t h i s experiment died as a r e s u l t of spraying. Time for death of t h i s percentage was shorter than f o r the same percentage i n Experiment IX, despite 3 1 . the lower concentration. I t i s thought that the inhalation exposure' and the greater age of the chicks i n this experiment were the factors causing the increased rate of death. Excessive preening was most noticeable i n this experiment as well as i n the former. It is: s i g n i f i c a n t that t h i s excessive preening was not due to d i r e c t oontact with the skin but was an inherent e f f e c t of the toxic m a t e r i a l s TABLE X 15$ Parathion at 12 lbs./acre on pheasants only Steam sprayer, spray.in very f i n e p a r t i c l e s (steam mist)  Chicks Age When Date of Cause of nos.o sprayed death death 1 25 days Aug. 8 Aug. 8 spray. 2; * ttI* tt 3 it, » A u g . 2.1 * 4 a. » it it 5 » » Aug. 17/ * 6: * * Sept. 20bruised head 7 * « Sept. 27 pecking 8 • ? * Sept. 28 •» 9 * »fc survived IQ y . . »' - » - -Experiment XI - Inhalation and Ingestion (Table XI). Ten birds, 15 weeks old, were exposed to food, water and a i r contaminated with 15$; Parathion on August 18. The modified conventional machine was used i n t h i s experiment and spray was applied at the rate of 7^ lba./acre* Seven chicks of the same stock and age were used as a control (Table XVII). 32. TABLE X I 15% Parathion at 7^ - lbs./acre on pheasants and food Conventional machine.with o s c i l l a t i n g spray table, spray i n droplets (fine fog)  Chicks . . . Age When Date of Cause of nos. - sprayed death death 1 15 weeks. Aug* 18 Aug. 25 pecking 2 * . » survived — -3 » it » 4 » it tt - — » 5 » tt »». 6 tt tt tt • « . « 7 »; it tt 8 H u. tt 9 w »' i* —-a 10 .-.»•_.. . a » — « No deaths attr i b u t a b l e to the effects of spraying occurred i n this experiment. The birds preened excessively fpr app-roximately 24 hours, aside from this no symptoms of toxic effects were evident* While increased age apparently decreased tolerance f o r DDT i t i s possible that the same s i t u a t i o n does not hold for Parathion; Perhaps older birds, feeding more on vegetable matter, have a greater tolerance for Parathion than the younger birds whose d i e t contains mora animal matter. On the other hand i t i s very probable that 7£ lbs ./acre of 15% Parathion approximates the threshold of tolerance for t h i s substance, with respect to the ring-neck pheasant© 33. Experiment-XII • Inhalation and Ingestion (Table XII). Nine birds, ten weeks old. were exposed to contaminated food, water and a i r . Handguns were used to apply Hexafoss at the rate of 10 pta./acre on August 22. Seven chicks of the same age and stock'were used as controls: (Table XVII). TABLE XII Hexafoss at 10 pta./acre on pheasants and food Conventional machine with handguns, spray in droplets (coarse fog) .. Chicks. Age . . . . . When Date of Cause of nos. sprayed death death -1 . 10 weeks: . Aug..22 . Aug* 23 spray 2 It! it M i tt 3 tt t> . Aug. 24 tt 4 tt tt survived mm—m 5 tt i t tt . . . . . 6 tt i t » — . » 7 tt tt! 8 tt tt? 9 U : I t Three of the birds in this experiment died as a result of spraying. These birds looked "dumpy* immediately after apraying and closely resembled a bird during the molting period. A l l birds shook their heads vigorously, from side to side, at the time apray was applied. Periodically-the ^dumpy* birds straightened up, shook their heads vigorously and returned to the "dumpy* position. The day after spraying, two birds lay on their sides convulsing intermittently. Con-vulsions terminated i n an odd position with the head lying 34. directly over the hack* One of these affected birds took extreme convulsions, exhibited C i r c u s * movementsj resulting from a wild kicking of the legs, flopped i t s free wing violently and lay dead. A l l this took place in the space of 31 minutes and the f i n a l outbreak of convulsions with "circus" movements took about five minutes. The second bird exhibited the same symptoms, without the flopping wing, and died two hours later* The third chick to die did so on August £4 with actions similar to those already described* Hexafoss is obviously toxic at some concentrations. Whether .inhalation exposure is more deadly than ingestion exposure i s not known* The toxic material evidently affects the central nervous system resulting in convulsions" and an odd position of the head. This material is not widely used at present but may have increased use in the near future depending on experiments for the control of orchard pests s t i l l being conducted* Experiment XIII -» Inhalation and Ingestion (Table XIII). Nine birds, ten weeks old, were exposed to contaminated food, wfcter and air on August 22:. Handguns were used to apply Lindane at the rate of 5 lbs */acre• The control group used was the same as for Experiment XII (Table XvTl). Six; of the birds in this experiment died as a result of spraying, one died from pecking and two survived. A l l birds humped up, with heads drooping and eyes closed, immediately 3 5 6 after spraying* Four hours later a l l birds had their heads thrown directly over their hacks in the same position as that observed for Hexafoas... On August 2 3 * the day after spraying, three birds died* Two were dead upon arri v a l at the pen in the morning* The third chick was observed, standing humped up, with i t s head directly over i t s back -with no warning of any sort i t f e l l over on i t s side and was found to be dead* Two birds the following day were observed to die in the same manner .with no symptoms other than general apathy and head thrown directly over the back. TABLE XIII Lindane at: 5 lbs./acre on pheasants and food .. .Conventional machine with handguns, spray.. in droplets (coarse fog) Chicks . .Age . .. ..  When . Date of .Cause . of nos* sprayed death death 1 . 10 weeks.. Aug* 2 2 Aug* 2 3 spray 2 tt it 3 tt; tt w> tt 4 tt Aug. 2 4 it 5 tt » • Its tt; 63 tt" tt tt peeking 7 tt tt Aug. 2 7 spray 8 tt » survived 9 •••• tt Ammm-• It i s evident that Lindane is toxic to pheasants even in small concentrations. The symptoms exhibited by the birds indicate a nervous disorder of some sort but of a vastly different nature than that observed i n other experiments* This insecticide has not been extensively used to date as i t 36 » i s comparatively new* Its predecessor, benzene haxachloride with a low gamma rating, had an unpleasant odour which pers-isted on the apples and restricted i t s use* Lindane, the modern benzene hexachloride, has less odour and possibly w i l l not taint f r u i t * Lindane is also a more successful pest k i l l e r than i t s predecessor* In consequence i t may become a widely used insecticide in the near future* Controls. (Tables XIV, XV, XVI, and XVII). The birds of the control groups were not sprayed at any time and were, in almost every other way, similar to the experimental groups* The matter of shade trees and slight food differences has been shown previously. Another difference is that some of the experimental birds became quite wet during spraying operations while the corresponding control birds were not wetted. It was f e l t that i n this preliminarjr study, the wetting of sprayed birds was actually an effect of orchard spraying* In future work i t would be well to set up control groups and throw water on them at the time their corresponding experimental groups are sprayed. In this way the effect of the toxic material i t s e l f w i l l be tested. In the present investigation, a l l birds were soaked by sudden rainahowers i l l with apparently no.effect. F i f t y percent of the control birds died during the study but none showed any of the symptoms described for the various spray materials. When the experimental birds died from spray 3 7 * there was no doubt as to the cause, inasmuch as symptoms were so very marked. Cause of death of control birds was always obvious and explainable by mechanical means-. TABLE X I V Control # 1 NOT.SPRAYED _ Chicks Served as control.. Date of . Cause of nos • for Tables - - death death . 1 . I I and I I I Oct. . 1 3 . pecking 2. w survived 3 it TABLE -XV Control # 2 . N O T SPRAYED . . Chicks . Served as control. . Date of Cause of nos • for Tables - • death death . 1 I V , V I I and I X July 1 6 trampled 2 n.' » n 3 » July 1 7 broken ne< 41 n July 2 3 n.-5 it July 2 8 trampled 6 Hi Aug. 3 0 shipment 7 tt Oct* 5 peeking 8 tt Oct. 1 7 «.' 9 «> it 38 o" TABLE XVI Control # 3 .... ... MOT SPRAYED. - . ; r Chicks . Served as control. Date of. Cause of noso for Tables death death .1 VI and X . Aug. 14 trampled 2 II it 3 II Sept. 27 bruised head 4 It! Oct. 3 pecking 5 tt survived — - • » • » . . & it Us 7 it It — - * » 8 " it It 9 it u. . . . . 10 ii •II TABLE XVII Control # 4 NOT SPRAYED Chicks . Served as.control- Date of Cause of nos« for Tables de ath death , Aug. 20 choked .., XII and XIII 2 II Oct. 13 broken neol 3 M. survived 4 11: n . . . . 5 a. it . . . a 6: ifc it •>..•» 7 II tt. Experiment XIV - Residual Effect. There is some experimental evidence that DDT at least may be accumulated in the body fat of vertebrates. Small quantities not sufficient to cause death themselves, are stored and the total of these small additions is sufficient to cause death i f i t is released into active body processes. If this is the 39. case, a b i r d , apparently healthy, may succumb to the toxic material when an amount of the substance exceeding the threshold of tolerance i s reached or when a stored amount exceeding the threshold of tolerance i s released to the. body i n an available form* In an attempt to test the r e s i d u a l e f f e c t of the various i n s e c t i c i d e s , the survivors of Experiments I - XIII i n c l u s i v e and the unsprayed survivors of the control groups, were subjected to a period of starvation* It was believed that birds with a stored overdose of spray, when starved, wou&d use up their body fat s and thus l i b e r a t e the stored material* The birds to be used i n th i s experiment were crated at Kelowna and shipped to the Department of Eoultry Husbandry at the University of B r i t i s h Columbia where they were placed In a clean chicken-house and fed wheat and poultry mash. Some birds died from various causes such as pecking, trampling-and concussion* The r e s u l t was that only 29 birds were available for th i s experiment. These 29 birds were i n groups as follows: DDT from Experiment V • - — — • -4 Mono DN from Experiment VIII -—• 2 Parathion steam mist from Experiment X--2 Parathion from Experiment XX — 5 Hexafoss from Experiment XIX-= ----»-6 Lindane from Experiment XIII- 2 Control #1 (Table XIV)- — 1 40. Control #" 3 (Table XVT)»- — 3 Control # 4 (Table X V T l ) ~ — - - 4 Tot a l 29 The pheasants were fed regul a r l y and weighed once a week u n t i l they attained a r e l a t i v e l y constant body weight. On November 7 a l l food was removed and the birds were weighed every day u n t i l November 17 when food was returned. In actual f a c t , the birds were able to get some food from the earthen f l o o r of the chicken-house but thi s source was almost com-p l e t e l y exhausted on November 9, two days after food was removed• The birds l o s t an average of 25% of the i r body weight during the starvation period. There was no s i g n i f i c a n t difference i n rate of loss of body weight among the nine groups. One of the birds exposed to Parathion steam mist (Experiment X) and one exposed to Parathion (Experiment XI) died during the starvation period. One of these died as a re s u l t of pecking and the other died from a broken neck when i t somehow managed to get i t s head through the f i n e l y meshed stucco wire fronting the chicken-house. A b i r d from Control # 4 and a bird from the Hexafoss experiment died as a r e s u l t of pecking after the starvation period was over. None of the birds exhibited symptoms c h a r a c t e r i s t i c of the spray materials used. In short, no evidence of a re s i d u a l e f f e c t was observed for any of the materials tested i n this experiment* The r e s u l t s are not conclusive when one examines the time 41b birds were exposed to t h e i r p a r t i c u l a r spray material: DDT (Experiment V) -Aug. 11 - 29 Hono DET (Experiment VIII-)— rAug. 18 - 29 Parathion steam mist (Expt. X)----25 minutes Parathion (Experiment XI)-- — Aug. 18 - 29 .Hexafoss (Experiment X I I ) - Aug. 22 - 29 Lindane (Experiment XIII) Aug. 22 - 29 It i s possible that the birds were not exposed f o r a s u f f i c i e n t time to accumulate more toxic material than they could t o l e r a t e . 42. FIELD OBSERVATIONS ON THE EFFECTS OF ORCHARD SPRAYING ON WILDLIFE OTHER THAN PHEASANTS. E f f e c t of Parathion on Mourning Dove (Zenaidura macroura): On June 9, Parathion was sprayed on a hen mourning dove s i t t i n g on two eggs. Spray was applied ftt the rate of 7^ l b s . (15% wettable powder) per acre using the conventional machine equipped with the o s c i l l a t i n g table. A good deal of the spray f e l l d i r e c t l y on the bird and she was quite wet. The b i r d and nest were watched constantly for three hours and she behaved l i k e any other wet b i r d . On July 6, the mourning dove mentioned above had two young and i n the meantime another nest had been b u i l t two trees away. This new nest was occupied by a hen s i t t i n g on two eggs.. Both nests were again sprayed with Parathion at the rate of 9^ lbs ./acre (15% wettable)* Spraying was carried on with the same equipment as before. The young of the f i r s t nest flew h e s i t a t i n g l y the next day keeping to the ground f o r the most part. On July 14, the hen was brooding two more eggs which hatched and the young flew successfully on August 13. The second mourning dove hatched her two eggs on July 20 and the,^ flew on August 3* Both mothera had been heavily wetted during this second spray and neither showed any unusual action. During the whole 43o 2 study neither dead nor a i l i n g doves were found* Cedar WaxwingSi (Bombycilla cedrorum): On July 19, a nest containing f i v e young cedar waxwings-was sprayed with 9 l b s . of DDT (50%^) and 3# l b s . of Parathion (15%} per acre* The two adults were perched i n the tree but not on the nest at the time of spraying. A l l . b i r d s became quite wet." Spraying was done with a concentrate machine and a great deal of f i n e mist and vapour was involved. The young- were only p a r t l y feathered on t h i s date and l e f t the nest on August 3. The family group remained i n the orchard u n t i l August 6 and were not seen thereafter. E f f e c t of Spray on Domestic Chickens: On June 26, concentrations of 6 l b s . of DDT (50%) and 2 l b s . of Parathion (15%) per acre were s.prayed on pear trees surrounding a chicken-house.- The house contained 67 cockerels, seven weeks old; two geese, s i x weeks old and 38 turkeys, nine weeks o l d . Spraying ceased at 3:00 P.M. and the poultry were l e t out of the chicken-house at 3:30 P.M. By 5:00 P.M. nine cockerels had died with convulsions and tremors} one was i n severe spasms while seven others were groggy and showed occasional tremors* These seven birds were revived by forcing epsom s a l t s and milk. The rest of the poultry were not affected* 44. The bantam and New Hampshire hens, used to mother pheasant chicks i n spraying experiments were exposed along with t h e i r chicks t A l l hens survived and only i n the t r i a l s using Parathion and DDT and those using Parathion did they show any noticeable e f f e c t . In both instances the birds exhibited excessive preening• E f f e c t of Spray on Bluebirds ( S i a l i a currucoides): Following i s an account of observations on a family of mountain bluebirds which were nesting i n a packing shed i n the centre of ah orchard. These birds had access, within th e i r c r u i s i n g radius to areas sprayed with Parathion, Mono DN, DDT, Soap and C r y o l i t e . Further, a large pool of water, containing some of a l l the above sprays, lay within 50 f t . of the nest. This pool was formed by the overflowing of the -spray tank and after p a r t i a l evaporation of the water i t was presumably a potent mixture. June 17 - 7:00 A..IL. - one pair of mountain bluebirds perching on the edge of the water tank - the male has tremors and occasional con-vulsions .- he f l i e s , poorly and f l o p s to the ground to rest at frequent i n t e r v a l s -he apparently cannot stay perched on anything f o r any 45,© length of time. 7:20 A.M. - female exhibiting s l i g h t tremors while male i s s i t t i n g under the eaves of the packing shed with severe tremors and convulsions, apparently unable to f l y . 7:30 A.M. - male i s dead but no sign of cause can be found - crop contained two small grass-hoppers. 7:36 A.M. - female flew into hole at side of packing shed to the accompaniment of much cheep-ing from young. June 19 - 8:30 A.M. - three young bluebirds found dead on ground below nesthole and English sparrows seem to have taken over - search f o r adult female was made and she was found, badly mutilated under the loading platform » she had apparently been mouthed a great deal by a dog. In another instance, two bluebirds had a nest i n a Robinia tree at the edge of an.apple orchard. -The male 46.© disappeared on the day of spraying and the female showed convulsions and tremors toward the end of the day* The next morning the female was dead and one of the young had severe tremors. The chicks were brought into the house by the owner of the orchard.- One of the young died i n two days with severe tremors and convulsions. The other chick suffered minor tremors but these soon disappeared; the b i r d was released and not seen again. DDT was the only i n s e c t -icide used within a mile and one half radius of the nest© Two other mountain bluebirds, a hen and a cock, died i n the writer*a hands. Both birds had severe tremors and convulsions, were unable to stand and could not support their heads. These two birds had been sprayed the day before with DDT at the rate of 25 lbs.* (50$) per acre; In addition to the former accounts, four mountain bluebirds (two hens and two cocks) were found dead i n the orchards; No cause of death was evident at post mortem and i t i s assumed that these birds died as a r e s u l t of spraying.• A l l four birds, were adults • E f f e c t of Spray on Robins (Turdus migratorius): The majority of work on robins was done on one orchard which covered 116 acres* A count was kept of the number of observation hours spent i n the orchard and of the.number of birds seen. One observation hour i s here defined as an hour spent cru i s i n g the orchard and used s o l e l y to observe and 4 7 o count birds* This method was adopted because one cannot "po s i t i o n * a b i r d while working with pens, spray machines, etc* and there ia a greater chance of counting the same bi r d more than once• Figure 1 shows the r e s u l t of orchard observations by months* It i s s i g n i f i c a n t that the number of robins per observation hour gradually decreases from June to August* This period should show an increased population r e s u l t i n g from the addition of the young of the year. I t seems evident that some cause of mortality was reducing the robin population* During the study, i t was found that robins congregated on the roof of the packing house i n the base orchard (116 acres). These congregations occurred between eight and nine o'clock i n the evening* When time permitted a count was made between these hours* Table XIX shows the r e s u l t of these counts and i t i s evident that a decrease i n population made i t s e l f f e l t here as well* Table XVIII shows the sex r a t i o s of dead robins by months• Those birds which were unidentified were those too -decomposed for study and four nestlings found i n June* Apparently both sexes^ are equally affected by toxic spray materials although the sample i s small* It was d i f f i c u l t to determine which sprays had been used on any p a r t i c u l a r robin because of the movements of the large numbers involved. In one instance however, Parathion was sprayed on a nest containing four young robins and the Month Observation hours Number of robins May' June July Aug. 60 40 20 1 1 1 I 1 1 20 40 60 80 100 120 140 1 1 1 1 1 1 -1 1 1 1 1 1 1 1 I V/A '//A /^ -- indicates dead robins r i g . 1. Number of robins and hours spent i n observation by months. 48. adult hen on a nearby branch. Spray was applied at the rate of 11 l b s . (15$) per acre and no e f f e c t was noticed. The young flew three days l a t e r , apparently normal. TABLE X V I I I S:ex r a t i o s of dead robins by months Month Total dead Males Females Unknown May 0 0 . 0 0 June 18 9 4 5 July 16 4 7 5 August 8 4 4 0 Total 42 . 17 15 10 TABLE X I X Evening counts of robins Date Count on. packing shed roof .. June 19 40 21 39 tt! 25 29= JUly 9 15 » 10 18 it 17 24 tt 23 13 Aug* 13. 8 19 7 In ano.ther case four young robins were sprayed with DDT on June 15 by one of the l o c a l ranchers. He reports that these birds showed severe quaking motions, that one died the day after spraying and the other three died on the next 4 9 » morning'* These birds had l e f t the nest but could not f l y too well and he reports that they did not move outside a t h i r t y foot c i r c l e during the whole three days. Spray had been applied at the rate of 13 l b s . (50%) DDT per acre. E f f e c t of Spray on Sparrows: During the study four song sparrows, three chipping sparrows and one white-crowned sparrow were found dead. T36 cause of death was found and a l l birds were i n good condition. The white-crowned sparrow had been feeding on seeds and flowers of Polygonum convulvulus while the others had"fed e n t i r e l y on insects. One of the chipping sparrows and one of the song sparrows were seen before they died. Both birds had tremors, convulsions,and the wings were out of c o n t r o l . E f f e c t of Spray on Q.uail (Lophortyx c a l i f o r n i c a ) : fejuail were extremely abundant throughout the study period. They apparently suffered no harm from orchard practices and generally flushed a good distance ahead of any disturbance. One pair was outstanding i n i t s parental behaviour. The hen had a stump foot which made her easy to d i s t i n g u i s h and the pair could always be found i n an area of not more than three acres. The pair were seen with f i f t e e n very young chicks on June 12,, 16 and 17, but on June 19, only the cock and f i f t e e n young were seen. A. search was made for the 50. hen and she was found very much a l i v e * s i t t i n g on ten eggs* On July 17, the pair were together again and now had two d i s t i n c t broods, one of f i f t e e n and the other of ten. On July 23, the cock and his two broods were seen while the hen was not i n evidence u n t i l August 16. On t h i s date both adults, were found with a brood comprised of f i f t e e n , ten and eight young of three d i f f e r e n t ages. Probably t h i s i s a case of brood t r a n s f e r a l and/or of nest robbery as i t i s a l i t t l e d i f f i c u l t to v i s u a l i z e a bird overcoming so quickly the psychological and physiological changes involved i n ceasing to incubate and to begin l a y i n g . From June 12. to the termination of the study on August 30, no adults were seen without young. . In the l a s t two weeks of August, large coveys were seen of mixed age groups. During the whole summer only one q u a i l was found dead* This bird was a cock and had been shot with a .22 ca l i b r e r i f l e . EC symptoms ind i c a t i n g toxic spray e f f e c t s were seen* General Discussion: DDT then, i s noticeably harmful to some birds when applied at concentrations of 5 lbs./acre or more. Other substances are also harmful to a lesser extent on avian pop-ulations. However, any substance which s i g n i f i c a n t l y affects any animal population i s apt to have a damaging e f f e c t on other populations, i n the long run, by breaking the food chain. This w i l l apply equally well to sprays such as 5.1* arsenic, black leaf *40 w, and others that s i g n i f i c a n t l y a f f e c t insect populations. Indeed, after the f i r s t spray i s applied, sometime i n June or late May, the whole ecology of much of the Okanagan Valley i s changed. Thus the western flycatcher (Empidonax  d i f f i c i l i s d i f f i c i l i a ) . the western wood pewee (Myiochanea  richardsoni riehardsoni) 3and T r a i l ' s flycatcher (Empionax tr a i l l i ) y w h i e h were abundant i n the orchards during May, were not seen i n the orchards after the f i r s t spray i n June but remained outside the orchards altogether or were seen occasionally on the very edge© English sparrows (Passer domesticus domesticua) were found i n greater numbers i n the orchards after the f i r s t , spray than before. Pew of these birds nested i n the orchards (three nests i n the packing shed of one orchard) and no nests were found i n f r u i t trees. Evrening grosbeaks (Heaperiphona vespertina)were found i n the orchards, and the area surrounding them at Kelowna, u n t i l the end of May when they seemed to leave the region e n t i r e l y . These birds returned i n August but did not go into the orchards at thi s time. House finches (Carpodacua mexicanus )wsre found i n the orchards u n t i l the end of May but after t h i s they remained i n the surrounding area and did not ventnne into the orchard. Mourning doves occurred i n many orchards and often nested i n prune-plum trees. They did not appear to be affected by 52. any spraying p r a c t i c e . They are surely not affected by Parathion applied at the rate of 7# l o 9;§- l b s . (15%) per acre. Cedar waxwings were found i n only one- orchard although they were abundant i n the surrounding area. The family sprayed with DDT and Parathion was ce r t a i n l y not af f e c t e d . Mountain bluebirds are found i n many orchards and th e i r population i s reduced by DDT i n these orchards. Whether or not other sprays harm thses birds i s not known as yet. Robins are also common birds i n the orchards and are probably affected by DDT more than i s any other species. Parathion up to 11 l b s . (15%) per acre does not have any apparent e f f e c t on robins. Of the sparrows, the song sparrow (Melospiza melodia) i s most affected by toxic materials and i s the most common i n orchards. The chipping sparrow ( S p i z e l l a passerina  arizonae) i s the next most common sparrow and i s also affected to quite an:extent. The white-crowned sparrow (Zonotriohia leueonfarys) was p l e n t i f u l i n the orchards u n t i l the l a s t week i n May and only one specimen found dead dm June 21, was seen from May u n t i l August 28 when eight were seen on a ponderosa pine about 200 yards from the edge of an orchard. Q,uail, although i n the orchards off and on throughout each day, were apparently not affected by i n s e c t i c i d e s . Granted that many birds are severely affected by the use of i n s e c t i c i d e s , i t does not follow that orchard spraying i s the cause of an o v e r a l l population decline i n those species. 53b The present study indicates, that an ov e r a l l e f f e c t i s possible for two members of the thrush family, the robin and the moun-t a i n bluebird, because of the i r s u s c e p t i b i l i t y to the toxic sprays and their habit of frequenting orchards. Uo census of these populations was carried out i n non-orchard areas however. Hence no r e a l idea of the reduction i n the avian population as a whole i s indicated. 54 o DISCUSSION OP CHEMICAL ANALYSES AS A RELIABLE SOURCE OF EVIDENCE OF DEATH FROM TOXIC SPRAYS During the study period, several hirds were taken to the Dominion Entomological Laboratory at Summerland, B*C. where they were analyzed f o r DDT by the t o t a l chlorine method. Table XX shows the r e s u l t of these determinations. Birds: A, B, G, D and E were stored temporarily in wide-mouthed containers because of a shortage of narrow-mouthed sample bottles* Some evaporation took place and for t h i s reason these birds were not analyzed quantitatively* Qualitative tests were run on a l l samples, using the material salvaged from the quantitative t e s t s . Relative response to the q u a l i t a t i v e tests i s indicated by (') signs. These res-ponses cannot be used to compare the r e l a t i v e amounts,present i n the b i r d s . DDT contains 50.10% chlorine, therefore the column headed -"DDT (p.p.m.)'* has been obtained by multiplying organic chlorine by two. Birds contain a c e r t a i n amount of natural organic chlorine as i s shown by b i r d G, an unsprayed control chick. I t w i l l be noted upon examination of Table XX that i f the chlorine present i n the control chick i s subtracted from a l l other birds (a necessary subtraction i n that chick G r e a l l y 554 contained no DDT but merely the normal amount of organic c h l o r i n e ) , these birds w i l l have a negative chlorine hence a negative DDT value i n most oases. It i s further noted that birds Q to W Inclusive mere exposed to 50%* DDT at 18 l b s . per acre and shorn a lower value than chicks H to K inclusive which were sprayed with 50% DDT at only 13 lbs./acre. The conclusion to be drawn from the chemical analyses i s that they do not s u f f i c e as a means of determining death from toxic sprays. These birds did die as a r e s u l t of orchard spraying regardless of analyses• Histopathological studies are apparently i n the same category as chemical analyses as a r e l i a b l e source of evidence of death from toxic spray materials. ¥ork of histopathological nature has been done by M l l i e and Smith (16), Woodward et a l (29) and others. The general re s u l t s are neatly expressed by Heal (19) when he says, *Ths p r i n c i p a l histopathological findings i n animals exposed to high concentrations of DDT are moderate, subacute degeneration of the l i v e r . Histopath-o l o g i c a l changes i n the brain and spinal column of animals dying with t y p i c a l DDT tremors are very s l i g h t . In f a c t , s u f f i c i e n t pathological changes have not been found i n any organs to account for the death of the animals."* This also i s borne out i n the present study, for although neither time nor equipment was available f o r detailed microscopic study, only one case showed any noticeable tissue change and t h i s was not damaging enough to have caused death of the animal. TABLE, XX CHEMICAL ANALYSES 03? POISONED BIRDS: Source of Bird: Identification Spray Used . Quantitative Qualitative Organic DDT DDT Chlorine (p©p ©m©) Test (p.p.m.) ... Table I A. . . 15% .Parathion at 9 lbs ./A . •»*»•» t B and 11»1 * . C 50% DDT at 18. lbs ./A - r 1 1 1 Adult Robin D. Unknown * » J U T * Robin E tt t » Wild E tt. 216 432 Control . a Not sprayed 66 132; Wild H . . 50%. DDT at 13 lbs ./A 292 584 * » I » 204 408 t t 1 tt! J tt 230, 460 t t t Hi K 258 516 » t « Table II L 15% Parathion at 7f lbs ./A 4 8 * 1 t M and 70 140 * t » 1 N 50% DDT at 15 lbs./A 8 16 » 1 t n 0 . . . 4 8 * t * it P 4 8 * . Table III - - _ 50%. DDT at 18 .lbs./A .12 24 t » it. K it 14 28 ' » tt s: » 0 0 t * tt T its 18 . 36 • tt U i» 60 120 * * tt V 40 80 tt . » 14 28 Table VII.. X . Mono DN at 60 02../A 14 ' 28 » ttf Y a*ncL 0 0 t t 1 DDT in Unknown amount t . Table IV 1 . 50% DDT at .18 .lbs ./A 16 32 t i t 2 it 0 0 57 o I t would appear that histopathological and chemical analyses of animals r e f l e c t many d i v e r s i t i e s observed i n the animals and spray materials* I t i s apparent also that some factor (or factors) other than the amount of toxic material i n the body must be considered* Thus Goburn and T r i e c h l e r (5), working with laboratory animals, found considerable v a r i a t i o n i n the toxic action of DDT due to v a r i a t i o n i n the rate of absorption, elimination and/or difference i n path-o l o g i c a l reaction i n the animals studied. They found that larger dosages resulted i n a higher mortality but that survivals occurred i n nearly a l l cases. Logier (17), working with amphibians and r e p t i l e s , found that separate individuals of a species did not always react i n the same way and that the degree of poisoning was presumably influenced by other factors than the amount of the toxic substance alone. He suggests that the presence of food i n the stomach may increase the absorption of DDT that has been taken into the body orally» In the present study a great deal of v a r i a t i o n appears i n the toxic effects of the i n s e c t i c i d e s used. Regarding DDT, Experiment ¥ 1 shows that a l l birds exposed to DDT mist died i n two days while 40%' of the birds i n Experiment Y are al i v e at the present time (February, 1950). A si m i l a r s i t u a t i o n , though not as clear cut, occurs i n the case of Parathion. Yet, when both apparently harmful i n s e c t i c i d e s were sprayed on pheasants (Experiments I and II) there was 58 di again a v a r i a t i o n i n the time f o r death of a l l birds from two days to 60 days* Further v a r i a t i o n may be seen among the individuals of any one experiment* A case i n point i s the description of the reaction of pheasant chicks sprayed with Parathion and DDT i n Experiment I . In f a c t diversity' i s shown by a l l the in s e c t i c i d e s used i n this study with the possible exception of Mono DN. Other sources of v a r i a b i l i t y i n the toxic e f f e c t s of in s e c t i c i d e s are caused by climate, p u r i t y of the toxic substance and solvent used with the harmful reagent* The b u l l e t i n e n t i t l e d "Forest spraying and some effects of DDT (6, 15, 17) s.tates: on page 160 that, "aurfaces coated with DDT preparation may k i l l c e r t a i n insects several months afte r treatment i f not exposed to r a i n or sunlight." I t i s also pointed out here that a l k a l i decomposes DDT and reduces the res i d u a l e f f e c t . Gunther (10) found that during the summer* i n C a l i f o r n i a where f r u i t temperatures may exceed 125 degrees Fahrenheit^ two weeks was more than s u f f i c i e n t to eliminate toxic effects of DDT while under winter conditions there was l i t t l e d>f any loss of t o x i c i t y over several months. Slade (23) found that crude benzene hexachloride given o r a l l y to rats i s markedly less toxic than the gamma isomer. Some solvents such as kerosene, evaporate quickly leaving needle-l i k e crystals that are very durable, the toxic e f f e c t l a s t i n g from three to s i x months under outdoor weathering (8). DDT i n non-volatile solvents i s absorbed through the skin and 59« solution of DDT in fatty o i l s increases i t s toxicity (19)« Another factor, causing variability in pheasant mort-a l i t y more than chemical analyses, is the concentration of the toxic material applied. If the spray material is cumul-ative and a bird stores varying amounts from time to time, i t w i l l undoubtedly contain, at death, more of the toxic material than i s necessary for death. Chemical analyses w i l l be biased in this case. Furtherj i f the spray has a residual effect, a bird in the orchard may be subjected to very hagh concentrations. This high concentration may be sufficient to cause death at a single feeding by the end of the spraying season but until this time the bird would have ingested o£ inhaled varying amounts which would be stored in the body as they were individually not great enough to cause death. In the Okanagan Valley, the Department of Agriculture recommends that DDT should not be applied within 30. days of picking. It is also suggested that A i l should not be used as a solvent for DDT. It is possible that the residual effect of DDT in the Okanagan lasts for some time, although the present study could not determine the duration. It is an important factor to consider however, as most growers spray their orchards three to five times a season. If the residue lasts over the time when the next sprays are applied a multiplied concentration remains. Thus, i f DDT (5Q%~) was applied five times at the rate of 15 - 25 lbs ./acre, and i f the residue remained toxic to some forms throughout that time, the total 60, concentration a f f e c t i n g those forms would he 37.5 - 57.5 I D S . of actual DDT per acre. Most growers begin spraying i n June and stop i n August. In one orchard, watched c l o s e l y through-out the summer, the grower sprayed f i v e times between June 1 and August 12 and each time he sprayed an average of 30 l b s . (50%) DDT/acre. Thus, i n s i x weeks he had applied 75 l b s . of actual DDT per acre. In general then, many factors cause v a r i a t i o n i n the toxic effects of spray materials. These factors make i t very nearly impossible to use chemical analyses as a r e l i a b l e evidence of death from toxic sprays. Following i s an outline of f a c t o r s , any combination of which, w i l l cause a v a r i a t i o n i n the toxic e f f e c t of spray materials. A. . B i o l o g i c a l : 1. Age of the i n d i v i d u a l . 2. Physical f i t n e s s and resistance of the i n d i v i d u a l . 3. Metabolic a c t i v i t y and degree of e x c i t a t i o n of the i n d i v i d u a l when the toxic material i s contacted. 4. Food present i n the digestive t r a c t . B. Mechanical: 1. Size of spray p a r t i c l e s . 2. Concentration and puri t y of the toxic material i n the a i r contacting the animal and/or on the food the animal w i l l eat. 6 1 , 3o Solvents and other constituents used with the toxic substance. 4. Temperature and other c l i m a t i c conditions both at the time of spraying and after the spray has s e t t l e d . Further work on chemical analyses might lead to more conclusive r e s u l t s . If the conditions under which the toxic material i s applied are known then chemical analyses might show a c o r r e l a t i o n . 6 2 THE INFLUENCE OF ORCHARD SPRAYING AND OTHER FACTORS ON PHEASANT POPULATIONS Toxic E f f e c t : Three cocks, two hens, and fourteen young pheasants died as a r e s u l t of orchard spraying during the summer. Of these, one hen and four chicks were sprayed with 50% DDT at the rate of 13 lbs ./acre. The hen died f i r s t with severe tremors and convulsions. The four chicks appeared to be normal but the next morning two were dead and the remaining two had s l i g h t tremors. By noon, neither of the remaining chicks could stand* Severe convulsions were evident and they seemed to have no control of their wings. Both chicks were dead before night-f a l l . These four chicks are H, I , J , and K i n Table XX. A speed sprayer was followed for one entire day. The spray used was 50% DDT at an average of 21 lbs./acre. During the day three adult cocks were observed; One cock was observed running down an i r r i g a t i o n furrow p a r a l l e l to the course of the spray machine. The b i r d crouched and when the spray machine came abreast of i t , the b i r d received a good deal of f i n e mist from the machine. When the machine had passed the bird moved out of the d i t c h and slowly across the orchard. About f i v e minutes after emerging from the furrow the cock began to stumble i 63 c then jumped up into the a i r * In another f i v e minutes the bi r d was crouched on the. ground and e a s i l y approached. The cock had severe tremors, his eyes were closed and he could not hold h i s head up. Twenty minutes after being exposed to spray the bird f e l l on his side and i n a few seconds was dead. Another cock was found on his. side a short distance from the f i r s t . He exhibited s l i g h t tremors and severe convulsions and died shortly after he was found. The t h i r d cock was found dead about three hours l a t e r . Post-mortems were done on a l l three birds and no evidence as to cause of death could be found. The l a s t cock found had s l i g h t lesions on the r i g h t lung but these were not large enough to cause death. Three chicks were caught i n an orchard that had been sprayed one hour before. They appeared to be quite normal but the next morning a l l three chicks were dead. The spray used i n th i s instance, 50% DDT, was applied at the rate of 17 lbs ./acre. An adult hen was sent from Oliver to the writer for examination* This hen was reported to have died with tremors i n an orchard which had been recently sprayed. She had been accompanied by f i v e chicks which were said to be a l l r i g h t . No reason f o r the death of the hen could be found upon post-mortem examination* Two days l a t e r a t r i p to Oliver revealed that the f i v e chicks had died i n the same manner as the mother hen. The orchard concerned was small ( ten to twenty acres ) 64o and was completely surrounded by other orchards. Parathion had been sprayed on the orchard three days before the han and her brood were found. In the surrounding orchards, DDT and Parathion with DDT had been sprayed. Concentrations were unknown and estimates by the growers concerned ranged from four to t h i r t y pounds per acre: of DDT and s i x to seventeen pounds per acre of Parathion. Here again i s evidence that the adult birds die before the-chicks* The reason for this i s believed to be i n the food habits of the birds. The adults eat more vegetable material than do the Chicks. Habitat Preferences: Data on nesting densities was obtained whenever possible. Seven growers were as!v*?aL -. to watch for pheasant nests i n their orchards. The acreage covered i n these seven orchards t o t a l l e d 316 acres and the number of nests found i n this acreage was seven. One of the seven nests was a dump nest containing seventeen quail eggs and three pheasant eggs. One nest containing nine and another containing eleven eggs were flooded out during i r r i g a t i o n . Three nests containing nine, thirteen and twelve eggs respectively, were abandoned. The reason for abandonment i n orchards i s probably the constant a c t i v i t y which flushes birds at various stages of development. The mowing machines i n the orchards were followed on many occasions and only the few nests noted 65. above were found. Two. non-orchard areas were examined while mowing was in progress. One of these, a four aCre a l f a l f a f i e l d , con-tained eight nests t o t a l l i n g 87 eggs. The other f i e l d was a three acre oat f i e l d and i t contained three nests t o t a l l i n g 31 eggs. These nests were found before the mower passed over them and cover was l e f t around a l l the nests. Pour eggs i n the a l f a l f a f i e l d and two i n the oat f i e l d did not hatch. A 40 acre h a y f i e l d was searched by the author with the assistance of two dogs. Eighteen nests were found i n a l l . This h a y f i e l d was two miles from the nearest orchard. Time did not permit further observation of these nests but as they were found i n June and the hay was not cut u n t i l August, i t seems safe to assume that a good percentage survived. Regarding pheasant populations, Table X X I shows that for the Kelowna area the wild pheasants i n non-orchard areas s i g n i f i c a n t l y outnumber those i n orchard areas. Reports from Joe McLaughlin and W.B. Snow at Summerland also bear t h i s out i n their d i s t r i c t , for while pheasants do go into the orchards during the day they are found for the most part on the steep banks of ravines running down to the lakeshore. These banks have well interspersed cover of sagebrush (Artemisia sp.), antelope bush (Purshia t r i d e n t a t a ) . willow (Salix sp.), wild-rose (Rosa sp.), waxberry (Symphor1carpus racemosa) and sask-atoon (Amelanchier sp.) while an understory of grasses provides food and nest material. TABLE XXI ORCHARD VERSUS NON-ORCHARD .PHEASANT POPULATIONS Orchard Areas. . . . Non-orchard Areas Month Cocks Hens Young Observ. hrs • Total birds Cocks Hens Young Observ. hrs. Total birds; May-June 25 (5) 18 (1) 9 (7) (6) 12 10 16 44 . 21 18 10 0 5 28 July Aug. 0 1 2(1) 3. . 14 10 9 16 31 3 26 3 85 15 3 2 142 21 Grand 26 (3) Total 24(2.) 21 (14) 50 . 90 52 39 100 10 191 Brackets indicate dead birds; 67. Nesting i s now, and has been for several years, f a i r l y heavy i n t h i s sage-brash association according to Mr. McLaughlin* Although l i t t l e i s known of the pheasant density i n the orchard areas of Oliver and Osoyoos, Dr. I. McTvCowan t e l l s me that pheasants use the sagebrush association and uncul-tivated bottoms to a great extent i n these l o c a l i t i e s * Whether or not pheasants used the orchard areas to a greater extent before the advent of DDT, Earathion and other toxic spray materials i s not known. Reports of former abundance i n orchards do not concern breeding or nesting seasons but deal with the hunting season. This would seam l o g i c a l when one considers that picking i s s t i l l i n progress during the hunting period and many growers; w i l l not allow hunting at this time. Also, that a pheasant i n an orchard may escape the gun mora ra p i d l y than i n a grain f i e l d . A l l i n a l l the orchard serves as a suitable refuge from hunting-pressure for the ring-neck pheasant. The writer believes that the part of the pheasant population resident i n the orchards has always been small and that the bulk of the harvest which made the Okanagan Valley so desirable f o r hunting has always come from the non-orchard areas given over to mixed farming, grain and veg-etables which have s u f f i c i e n t dispersion of cover types * Some small acreages planted to f r u i t trees, widely separated from other orchards, and surrounded by a varied cover type probably have comparatively heavy densities but f o r the most 68 b part orchards do not provide preferred habitat. Many orchards are clean cultivated and do not provide food for pheasants. Other orchards with a cover crop (usually red clover) provide excellent food hut farming practices suoh as mowing, ditching, i r r i g a t i n g and spraying are not conducive to successful nesting-. Spraying here does not ref e r to the substance sprayed, rather the disturb-ance caused and the actual path of the spray machine• Further, orchards, generally speaking, are monotypic as to cover. Thus i n large contiguous orchard areas the fa c t o r s mentioned above- are apt to place a severe handicap on the production of large pheasant populations. Orchard Spraying as a Cause of Population Decline; Many persons have attributed the recent pheasant decline i n the Okanagan Val l e y to the use of toxic spray materials, p a r t i c u l a r l y DDT. It must be remembered however, that DDT and Parathion, the most toxic materials i n general use, were not available to the f r u i t growers u n t i l 1947 when the pheasant decline was already w e l l established. P r o v i n c i a l Game Commission Reports indicate that a peak i n pheasant population was reached i n 1942^ that a gradual reduction i n population occurred u n t i l the end of 1945 and that a dras t i c decline was evident i n 1946 and 1947 which resulted i n a closed season i n 1948. Further, i f the advent of toxic sprays, which are lim i t e d to orchards, was the only cause of 69 *> the recent decline i t had two possible e f f e c t s : (1) that spray material eliminated pheasant food and (2) that the toxic substance k i l l e d the pheasants d i r e c t l y . The f i r s t i s u nlikely i n that pheasants are vegetatians and have no sense of taste or smell (therefore adults not repelled) hence only the young chicks would be affected due to a dearth of insects. This argument hardly stands the test i n that a s c a r c i t y of insects occurred to the same, or nearly the same extent, p r i o r to 1947 when arsenic was used. The main reason for the use of the new i n s e c t i c i d e s i s that arsenic did not decompose i n the s o i l and was l i k e l y to hinder plant growth. Also that today three to f i v e sprays of DDT are applied at a comparatively low cost as compared to twice that many applications of arsenic at a much higher t o t a l cost. The second e f f e c t , k i l l i n g pheasants d i r e c t l y , i s a p o s s i b i l i t y shown by the experimental work, but is v ^ d i f f i c u l t to correlate with the large decline i n that i t necessitates a proportionately higher density of pheasants i n orchards than i s now evident* It seems most probable that other pheasants from non-orchard areas would move into orchard areas thus keeping the r e l a t i v e densities of orchard to non-orchard areas i n a more or less constant r a t i o . In other words, i f the orchard population had been high enough for toxic sprays to cause an o v e r a l l decline there would s t i l l be evidence of a higher population i n orchard areas than i n non-orchard areas . 70. Despite the arguments above however, there i s a poss-i b i l i t y of toxic sprays increasing the rate of decline or densiXy decreasing the population ^ which would have been r e a l i z e d i f toxic sprays had not been applied. There i s the further p o s s i b i l i t y of toxic sprays i n h i b i t i n g population increase i n that as the population increases more pheasants w i l l be found i n orchards and the more i n orchards the more w i l l die as a r e s u l t of orchard spraying. The Population Decline and i t s Causes; The problem now arises that i f orchard spraying did not cause the decline, what did? The problem i s not easy nor i s i t obvious and following i s a discussion concerning a number of p o s s i b i l i t i e s which may have caused the pheasant decline. The recent reduction i n pheasant populations has occurred not only i n the Okanagan but i n p r a c t i c a l l y a l l areas on the North American continent where ring-neck pheasants occur. In Ontario, Clarke and Braffette (4) report that the crash decline apparently began i n 1942 and reached i t s low i n 1945. The l i t -erature on the pheasant decline i n the United States i s well presented by Wandell (27) and Kimball (14) who cover the prob-lem as i t occurred i n some 25 states. The factors thought by various authors to have caused the decline are discussed by these two men but i t i s deemed desirable to again consider these 7 1 . points with p a r t i c u l a r reference, where possible, to the s i t u a t i o n i n the Okanagan V a l l e y . 1. Inclement weather - It i s thought by some that inclement weather was the causa for the decline i n their p a r t i c u l a r areas. The weather data for the Okanagan Valley does not show any good reason f o r considering t h i s f a c t o r . On the nationwide scale weather i s apparently not the cause of the pheasant population decrease, for many areas, l i k e the Okanagan, had no s i g n i f i c a n t changes i n t h e i r climates. Poor weather conditions may favour further decrease i n an already decreasing population. 2. Reduction of suitable cover - This factor may be of some importance i n the Okanagan as the human population has increased. Many places once suitable to pheasants are now homesites. Nevertheless, i t appears doubtful that such changes were s u f f i c i e n t to cause a pheasant decline though they may^aideoi decline. Such changes certainly do not explain the decline on a continental basis. Also the acreages devoted to various types of farming have remained r e l a t i v e l y constant. 3 . Increased hunting pressure - Hunting pressure i n the Okanagan has d e f i n i t e l y increased* Table XXII shows the increase i n sale of hunting licences for the four p r i n c i p a l communities i n the Okanagan V a l l e y . Increased hunting pressure would indicate a decline to many individuals i n that their bag returns would be smaller, 72. while i n actual f a c t the t o t a l number of birds bagged could tt be greater. A l l e n (2) shows that,the f i r s t 125 gun-hours harvest most of the crop and that hunting beyond that point r e s u l t s i n very l i t t l e . The r e s u l t s obtained by E:. Taylor (26:) at the checking stations i n the Delta municipality i n the Eraser Valley also bear. t h i s point out. TABLE XXII Increased Numbers of Hunting Licences 1947 over 1937 Year Vernon Kelowna. Penticton Oliver Total 1937 1386 930 1060 208 . 3584 1947 2341 2138 2011 656 7146 Schick (22) concluded that one cock could e a s i l y service ten to twelve hens intthe wild, hence reduction i n cocks would have to be very severe to cause an appreciable e f f e c t on breeding success. 4. M o r t a l i t y due to farming practices - Mowing i n the Okanagan, as i n other places, i s probably the largest, single mortality f a c t o r . I r r i g a t i o n causes some mortality but t h i s has been reduced i n recent years by introducing sprinkler systems which are more e f f i c i e n t , less costly i n the long run and cause less damage from erosion than the older d i t c h -ing method. However aside from the change i n i r r i g a t i o n methods farming practices have remained f a i r l y constant throughout the years. 73 5. P r e d a t i o n - T h i s f a c t o r i s of minor or of no importance i n the Okanagan so f a r as can be a s c e r t a i n e d . Predator c o n t r o l i s c a r r i e d on e x t e n s i v e l y by sportsmen's o r g a n i z a t i o n s and escape cover i s f a i r l y abundant i n most p l a c e s . Indeed fewer predators are seen i n the Okanagan than i n the F r a s e r V a l l e y or the p r a i r i e r e g i o n s of pheasant abundance. 6. Disease - This i s a p o s s i b i l i t y and l i t t l e i n f o r m a t i o n i s a v a i l a b l e on the occurrence of pheasant d i s e a s e s f o r any p a r t of B r i t i s h Columbia. Elsewhere, i n v e s t i g a t o r s have not a t t -r i b u t e d pheasant d e c l i n e to d i s e a s e and i t i s u n l i k e l y t h a t a d i s e a s e of such epidemic p r o p o r t i o n s as to cause a d e c l i n e would escape n o t i c e . 7. R e c e s s i o n of an i n t r o d u c e d s p e c i e s on a new range -K i m b a l l (14) says t h a t , "This remains an ominous p o s s i b i l i t y . " He p o i n t s out however t h a t South Dakot#a and other s t a t e s have had p r e v i o u s p e r i o d s of h i g h and low p o p u l a t i o n s , t h a t the r e p r o d u c t i v e r a t e i s again h i g h and t h a t pheasant p o p u l a t i o n s are i n c r e a s i n g . I t may be noted a l s o that a d e c l i n e f o r t h i s reason would probably have occurred l o n g before t h i s as pheasants were f i r s t i n t r o d u c e d i n the Okanagan V a l l e y around 1896. 8. S p r a y i n g - I t has a l r e a d y been shown that t h i s was prob--a b l y not the cause of the d e c l i n e but the f a c t remains that s p r a y i n g or any other m o r t a l i t y f a c t o r may speed up the r a t e of d e c l i n e and/cr r e s u l t i n a lower ebb than would have occurred without t h a t m o r t a l i t y f a c t o r . I t may a l s o suppress 74'. an i n c r e a s e to a new "'high*. 9-. E b s s i b i l i t y of pheasants being c y c l i c - F a c t s seem to i n d i c a t e t hat the p o p u l a t i o n c h a r a c t e r i s t i c of the r i n g - n e c k pheasant i s not f l a t as was f o r m e r l y supposed. Whether or not i t i s t r u l y c y c l i c remains to be seen. At l e a s t we may say that f l u c t u a t i o n s have been observed on a l a r g e s c a l e and that these f l u c t u a t i o n s a p p a r e n t l y r e s u l t from a cause or causes y e t unknown* 7 5 o SUMMARY AMD CONCLUSIONS To determine the e f f e c t of orchard spraying on pheasants, groups of these birds were placed i n separate pens and sprayed during the normal course of orchard spraying. Experiment V/III was an exception to t h i s general procedure when Mono DN was sprayed on trees i n an area for the sole benefit of experimental pheasants. Control groups of the same source and age were set up to compare with experimental groups. Table XXIII b r i e f l y shows the mortality r e s u l t i n g from spraying i n the various experiments. Following i s a summary of the results and conclusions f o r these experiments. Parathion and DDT -The symptoms observed i n these experiments were excessive preening, tremors, convulsions and occasional gaping. There i s evidence of a cumulative e f f e c t In Exper-iment I where three birds took several days to die after a. second spray had been applied. Birds of Experiment II died more rapidly than those of Experiment I. The rapid death i s attributed to the d i f f e r e n t food habits of older bird s . It i s believed that older birds, which eat more vegetable matter than young birds, are more susceptible to the toxic effects of a Parathion and DDT spray concentration. TABLE XXIII SUMMARY OP SPRAY EPPECTS ON EXPERIMENTAL PHEASANTS Spray ": Used . HOW: applied Age at Time of spray % death Resulting Refer to Table # 15% Parathion @ 9 lb./A 5:0% DDT @ 18 lb./A . Droplets on birds & food 5 days 100 I 15% Parathion @ 7f lb./A 50% DDT @ 15 lb./A it » 15 days 100 II 50% DDT' © 18 lb./A ir 15 days 78 III 50% DDT @ 18 lb./A Droplets on -food only 4 days 100 IV 50% DDT @ 15 lb./A Droplets on birds & food 14 wks. 50 V 50% DDT © 10 lb./A Steam mist on birds only 25 days 100 VI Mono DN @ 60 oz./A 50%" DDT unknown amt. Droplets on .food only 4 days 100 VII MOno DN © 60 oz./A Droplets on birds & food 15 wks. 0 VIII 15% Parathion @ 16 lb./A Droplets on food only 4 days 50 IX 15%. Parathion @ 12 l b ./A Steam mist on birds only 25 days 50 X 15% Parathion @ 75: lb./A . Droplets on birds & food 15 wks. . 0 XI Hexafoss @ 10 pts./A 10 wks. 33 XII Lindane @ 5 lb./A it. 50 XIII Control # 1 NOT SPRAYED 0 XIV Control # 2 it lb © XV Control # 3 n tt 0 . _ . XVI Control # 4 it II 0 XVII DDT -Symptoms observed for this spray were the same as for Parathion and DDT with the exception that excessive preening did not occur* Experiments I I I , IV* Y, and VI indicate that older birds are most susceptible to the toxic e f f e c t s of DDT; that 7|- lbs;, of actual DDT per acre i s close to the threshold of tolerance for pheasants when exposure i s of the ingestion type; and that inhalation exposure i s more toxic than inges-t i o n exposure. DDT and Mono DN -Symptoms; observed i n Experiment VII were the same as. those observed for DDT and i t i s believed that DDT was the toxic substance i n this spray. Mono DN -Results from Experiment VIII indicate that Mono DN has no harmful e f f e c t on pheasants. Parathion -Symptoms exhibited by birds sprayed with Parathion were excessive preening, convulsions and occasional gaping. No tremors were observed when Parathion alone was used. Inhal-ation exposure i s probably more t o x i c than ingestion exposure for Parathion. Experiment XI indicates that 15% Parathion at ii lbs ./acre i s close to the threshold of tolerance for pheasants* 78 o Hexafoss -Convulsion was the only symptom r e s u l t i n g from t h i s spray that was common to the groups above. Birds wxposed to t h i s substance always showed an increased a c t i v i t y of the lega j u s t before death and the head was always d i r e c t l y over the back. General dumpiness was the rule and reminded one of a bird i n molt. This insecticide may be widely used i n the near future and for t h i s reason i t should be more f u l l y experimented with. Lindane -Birds exposed to th i s material reacted much l i k e those sprayed with Hexafoss. However, less a c t i v i t y was involved. The birds were dumpy immediately after spraying and sat quite s t i l l with their heads under their wings. Those that died put their heads d i r e c t l y over t h e i r backs and did not move them again. They usually died a short while after putting t h e i r heads back. A l l of the sprays used, with the exception of Mono DN, are toxic to pheasants to some degree. DDT i s apparently most toxic of the sprays as they are applied i n the orchards. However, Barathxon seems to joe; a very close second. S u f f i c -ient experiments have not been made for other subatances to make any r e a l comparisons. An experiment designed to test the re s i d u a l effect of 79. spray materials showed no such e f f e c t . However, the experi-ment was not conclusive as these birds had not been exposed to sprays for very long and i t i s possible that they didrriot absorb a dosage large enough to be t o x i c . Three birds of Experiment I and the chicks of Experiment IV showed possible evidence of a residual or cumulative e f f e c t . However, th i s evidence may have resulted f i r s t , from i n d i v i d u a l differences i n the threshold of tolerance, second, from the increased from age of the birds which survived longest and^their change i n food habits. E l e l d observations indicated that DDT was toxic to pheasants, bluebirds and robins. Parathion and DDT together do not a f f e c t mourning doves or cedar waxwings but at l e a s t one of these materials i s toxic to young leghorn cockerels. Parathion had no e f f e c t on robins or mourning doves. As a matter of f a c t mourning doves and C a l i f o r n i a q u a i l were not affected by any spray material so f a r as could be ascertained. Song, chipping and white-crowned sparrows are k i l l e d by some spray material but i t i s not c e r t a i n which one. In general the whole ecology of the orchard areas i s changed a f t e r the f i r s t spray i s applied. Some food chains are apparently broken and birds move asat to areas of more abundant food. Other birds remain and are reduced i n population while s t i l l others such as the E n g l i s h sparrow seem to thrive on the areas where competition has been reduced. During the investigation certain birds were analyzed chemically. The results of these analyses show that they do 80 not provide adequate evidence of death from t o x i c s p r a y s . There i s a g r e a t d e a l of v a r i a b i l i t y i n the t o x i c e f f e c t s of spray m a t e r i a l s ; so much so that t o x i c i t y must be dependent on some f a c t o r s other than the amount of t o x i c m a t e r i a l a l o n e . An o u t l i n e of f a c t o r s i n f l u e n c i n g t o x i c i t y and p o s s i b l y r e s p o n s i b l e f o r the d i s c r e p a n c i e s i n chemical analyses are g i v e n below. B i o l o g i c a l : 1. Age of the i n d i v i d u a l . 2. E h y s i c a l f i t n e s s and r e s i s t a n c e of the i n d i v i d u a l . 3. M e t a b o l i c a c t i v i t y and degree of e x c i t a t i o n of the i n d i v i d u a l when the t o x i c m a t e r i a l i s c o n t a c t e d . 4 . Food present i n the d i g e s t i v e t r a c t . M e c h a n i c a l : 1. S i z e of spray p a r t i c l e . 2. C o n c e n t r a t i o n and p u r i t y of the t o x i c m a t e r i a l i n the a i r c o n t a c t i n g the animal and/or on food the animal w i l l e a t . 3. So l v e n t s and other c o n s t i t u e n t s used w i t h the t o x i c substance. 4. Temperature and other c l i m a t i c c o n d i t i o n s both a t the time of s p r a y i n g and a f t e r the spray has s e t t l e d . The pheasant d e n s i t i e s i n orchard areas are s i g n i f i c a n t l y 81, l o w e r t h a n t h o s e o f n o n - o r c h a r d a r e a s i n t h e K e l o w n a d i s t r i c t . R e p o r t s f r o m o t h e r d i s t r i c t s i n t h e v a l l e y a l s o s u p p o r t t h i s . I t i s b e l i e v e d t h a t o r c h a r d s p l a y o n l y a s m a l l p a r t i n t h e p h e a s a n t p r o d u c t i o n o f t h e O k a n a g a n V a l l e y , m a i n l y b e c a u s e t h e y o f f e r p o o r i n t e r s p e r s i o n o f c o v e r t y p e s a n d c o n t a i n t o o m a n y d i s t u r b a n c e s f o r s u i t a b l e h a b i t a t . F o r t h e r e a s o n t h a t o r c h a r d p h e a s a n t d e n s i t y i s l o w a n d t h e f a c t t h a t t o x i c s p r a y m a t e r i a l s w e r e n o t u s e d u n t i l a f t e r t h e p h e a s a n t d e c l i n e h a d s t a r t e d , i t i s b e l i e v e d t h a t o r c h a r d s p r a y i n g w a s n o t t h e c a u s e o f t h e p h e a s a n t s c a r c i t y . S p r a y i n g d o e s r e s u l t i n d e a t h o f s o m e b i r d s h o w e v e r , a n d l i k e o t h e r m o r t a l i t y f a c t o r s i t w o u l d p o s s i b l y r e s u l t i n a n l n c r e a s e d r a t e o f d e c l i n e a n d / o r a f u r t h e r d e c r e a s e i n t h e n u m b e r o f b i r d s s u r v i v i n g t h e d e c l i n e . A l s o a s t h e p h e a s a n t p o p u l a t i o n i n c r e a s e s a n d t h e m a r g i n a l o r c h a r d r a n g e i s f i l l e d , a h i g h e r m o r t a l i t y r e s u l t i n g f r o m o r c h a r d s p r a y i n g w i l l o c c u r . H e n c e o r c h a r d s p r a y i n g m a y l i m i t t h e u p p e r a s y m p t o t e t h a t a p h e a s a n t p o p u l a t i o n w i l l r e a c h . A g e n e r a l d e c l i n e i n p h e a s a n t p o p u l a t i o n s t o o k p l a c e t h r o u g h o u t N o r t h A m e r i c a a n d i t i s p o s s i b l e t h a t s o m e f a c t o r w a s c o m m o n t o a l l p o p u l a t i o n s . S e v e r a l p o s s i b l e c a u s e s f o r t h e d e c l i n e a r e d i s c u s s e d b u t n o n e o f t h e s e s e e m s a d e q u a t e . I t i s a p p a r e a t t h a t t h e p o p u l a t i o n c h a r a c t e r i s t i c o f t h e r i n g - n e c k p h e a s a n t i n N o r n n A m e r i c a i s n o t f l a t b u t t h a t i t d o e s s h o w f l u c t u a t i o n s . C y c l i c b e h a v i o u r c a n n o t b e a s c r i b e d t o t h i s s p e c i e s w i t h t h e i n f o r m a t i o n s o f a r a v a i l a b l e . 82 o SUGGESTIONS EOR FURTHER. STUDY During the study several approaches which would lead to a graater understanding of the effects of orchard spraying became apparent. Time did not permit following these ideas in the present study but i t was f e l t that the following suggestions might be a helpful guide to future investigations. 1. That experiments be set up to test the relation of food eaten to toxicity. Also whether birds w i l l actively take insects which have been k i l l e d by spray materials. 2. That experiments be set up to test the relation of age and sex to toxicity. Care should be taken that the birds have no choice of food because i f they do the diets of old and young birds w i l l not be the same. 3 . That control groups should be sprayed with water at the same time their comparable experimental groups are sprayed with insecticide. 4. That experiments be set up to determine whether certain mixtures of spray materials are mora toxic than the constituents alone. 5 . That certain birds be sprayed several times i f possible and kept well fed at a l l times. That these birds then be subjected to a period of starvation to determine the residual effect of toxic spray materials. 8 3 o It Is suggested that these birds ba of l i k e sex or equally divided. That an e f f o r t be made to correlate spraying proce-dures and spraying variables with chemical analyses. In connection with this suggestion i t would ba most he l p f u l i f future work was carried on at the Dominion Entomological Laboratory at Summer land, B.C. An adequate l i b r a r y i s available and i t would be much easier to keep i n contact with spray developments. Further, experimental sprayings are nearly always i n progress and experimental pens could be quickly placed with l i t t l e trouble and on a closer schedule than i s possible whan dealing with private growerso 84. LITERATURE CITED Adams, Lowell, M i t c h e l l , G. Hanavan, N e i l W. Hosley and 1949. David W. Johnston. The effects on f i s h , birds and mammals of DDT used i n the cont-r o l of forest insects i n Idaho and Wyoming. Jo urn. WiId1. Mgt., 13(3):245 - 254. What happened to the pheasants? Michigan Conservation 1 5 ( l ) : 6-8. Wisconsin pheasant populations. Wisconsin Conservation Department Publ. 326., A-466 A l l e n , Dur.ward L. 1946o Buss, Irven 0. 1943 » Clarke, C.H.D. and R.Braffette. 1946. Ringnecked pheasant investigations i n Ontario 1946. Coburn, Don R. and Ray T r i a c h l e r . 1946* Experiments on t o x i c i t y of DDT to w i l d l i f e . Journ. W i l d l . Mgt. 10(3):208 - 216. 85 o 6V Couch, Leo K. 1946. E f f e c t s of DDT on w i l d l i f e i n a Mi s s i s s i p p i River bottom wood-land, jr. Amer. W i l d l . Conf. Trans., 11:323 - 329o ?• Cowan, Ian McT. 1943. Economic status of the pheasant on the cult i v a t e d lands of the Okanagan "Valley, B r i t i s h Col-umbia. Report of the B r i t i s h Columbia Game Commission for 1942. 8. Craighead, E.C. and R>C. Brown 1945. Summary of tests with DDT i n 1944 for control of in s e c t s . U.S. Bureau of Entomology and Plant Quarantine, E-649, A p r i l . 9e Erickson, Arnold B. 1947. E f f e c t s of DDT mosquito l a r v i -ciding on w i l d l i f e . Part II -Eff e c t s of routine airplane l a r v i c i d i n g on b i r d and mammal populations. U.S. Public Health Reports, 62(35):1254 - 1262. 86, lO© Gunther, F'.A© Aspects of the chemistry of DDT. 1947o Journ. Ghem. Educ. 22 (May):238* 242. l l o Hope, G'.E. The effects of DDT on birds and 1 9 4 9 s the r e l a t i o n of birds to the spruce budworm Archips fumiferana Clem. Forest spraying and some effects, of DDT. D i v i s i o n of Research, Dept. of Lands and Forests, Ontario, Canada. B i o l . B u l l . # 2 , Pp 5 7 - 6 2 . 1 2 . Hotchkiss, N e i l and Richard H. Pough 1 9 4 6 . E f f e c t s on forest birds of DDT used for gypsy moth control i n Pennsylvania. JoUrn. W i l d l . Mgt. 1 0 ( 3 ) : 2 0 2 - 2 0 7 . 13. Kendeigh, Charles S. 1947. Bird population studies i n the coniferous forest biome during a spruce budworm outbreak. D i v i s i o n of Research, Dept. of Lands and Forests, Ontario, Can-ada. B i o l . B u l l . #1. 87. 14. Kimball, James W. 1948. Pheasant population character-i s t i c s and trends i n the Dakotas Amer. W i l d l . Conf. Trans., 13:291 - 314. 15. Leopold, Aldo 1933. Game Management. Charles Scrib-ner's Sons, New York. 16. L i l l i e , R . D . and M.I.Smith 1944. Pathology of experimental poison-ing i n cats, rabbits and r a t s , with DDT. U.S. Public Health Reports 59:979 - 984. 17. Logier, Shelley,E.B. 1949. E f f e c t s of DDT on amphibians and r e p t i l e s . Forest spraying and some effects of DDT. D i v i s i o n of Research, Dept. of Lands and Forests, Ontario, Canada. B i o l . B u l l . # 2, Pp 49 - 5.6. 18. Mitchell,R.T. 1946. E f f e c t s of DDT spray on eggs and nestlings of birds . Journ. W i l d l . Mgt. 10(3):192 - 194. 8 8 . 19. Neal, Paul A. 1945. DDT t o x i c i t y - - -. • A report on the t o x i c i t y to warm blooded animals of aerosols, mists and dusting powders containing DDT. S o a p and Sanitary Chem. 21(1): 99 - 101, 117. 20. Nelson,A.L. and EiW.Surber 1947. DDT investigations by the Pish and W i l d l i f e Service i n 1946. Special s c i e n t i f i c report i s s ' d May, 1947. Chicago, I l l i n o i s . 21. Robbins, G . S . and R.E. Stewart 1949. Effects of DDT on bird population of scrub f o r e s t . Journ. W i l d l . Mgt. 13.(1): 11 - 16. 22. Schick, Charles 1947 . Sex r a t i o - egg f e r t i l i t y r e l -ationships i n the ring-neck pheasant. Journ. W i l d l . Mgt. 11(4): 302 - 306.' 23. Slade, R.E 1945. Chem. Ind. Rev., October 13, Pp 314 - 319, taken from Kirk.H., 1946. DDT and gammexane;in 89. canine p r a c t i c e . Veterinary Record 58(43):465 - 466. 24. Spiers, Murray J . 1949. The r e l a t i o n of DDT spraying to the vertebrate l i f e of the f o r -est. Forest spraying and some effects of DDT. D i v i s i o n of Research, Dept. of Lands and Forests, B i o l . B u l l . # 2, Pp 141 - 158. 25. Stewart,R.E., J.B. Cope, C S . Robbins and J.W.' Brainerd. 1946. E f f e c t s of DDT on birds on the Patuxsnt Research Refuge. Journ. W l l d l . Mgt. 1G(3):195 - 201i 26. Taylor, Ernest W. 1950. M.A. Thesis, University of B r i t i s h Columbia. Status of the ring-necked pheasant i n the United States. U. Amer. W l l d l . Confi Trans., 13:291 - 314. 28. Wisconsin Conservation Department Pheasant Propagation Handbook. 2.7. Wandell, W i l l e t U." 1949* 90 c B i b l . 308, G-47. 29» Woodward, G.-, R* Offner and G. Montgomery. 1945• Accumulation of DDT i n body f a t and i t s appearance i n the milk of dogs. Science, 102, lags 177. 

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