Influence of aridity on reproduction of the collared peccary (Dicotyles tajacu (linn)) in Texas
department or school: Science, Faculty of
department or school: Zoology, Department of
data provider: DSpace
degree campus: UBCV
creator: Low, William A
issued: 2011-05-24T22:37:19Z
issued: 1970
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Reproduction and productivity of the collared peccary, Dicotyles tajacu angulatus, were examined in Texas under moist and draught conditions, and in captivity under presumed optimal conditions. Foetal sex ratios favour females, but change to favour males shortly after birth, and again favour females in the older age classes. The south Texas population contained a higher proportion of older animals than the west Texas population. Life expectancy at 1 year of age was estimated at 3.0 years in south Texas peccaries, and the average annual mortality rate was 21.5%. The mortality rate for west Texas peccaries was calculated at 27.5%. Animal condition, estimated from kidney fat and carcass weight, was highest in the late fall, and was significantly better in the year of high rainfall and good range conditions than during the drought year. Condition of the south Texas peccaries under good range conditions was almost as high as that of pen-reared animals, and under drought conditions almost as low as the west Texas peccaries under good conditions. Males mature sexually at just under a year. Although there are seasonal changes in the proportion of testis constituents, abundant sperm are present in at least some males at all times of the year. Females appear sexually mature at just under a year, but in the wild populations do not become pregnant until 16 to 20 months. Pen-raised animals have a fertile post-partum and lactation oestruses,; and generally, produce two lifters a year. In south Texas 33% of the adult sows showed ovarian evidence of consecutive pregnancies. During favourable range conditions 71% of the collected sows were pregnant and 41% had remated. During drought conditions only 2670 of the sows were pregnant and 9% remated. A good measure of consecutive pregnancies in, west Texas was not obtained, but it appears comparable to south Texas under drought conditions. There was no apparent decrease in reproduction in 15-year old south Texas and 9-year old west Texas…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/34781
note: THE INFLUENCE OF ARIDITY ON REPRODUCTION OF THE COLLARED PECCARY (PICOTYLES TAJACU (LINN)) IN TEXAS by WILLIAM A. LOW B.Sc. (Honours), University of B r i t i s h Columbia, 1962 A THESIS SUBMITTED IN THE REQUIREMENTS DOCTOR OF PARTIAL FULFILMENT OF FOR THE DEGREE OF PHILOSOPHY i n the Department of Zoology We accept t h i s t hesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA 1970 In presenting th is thes is in pa r t i a l fu l f i lment o f the requirements for an advanced degree at the Univers i ty of B r i t i s h Columbia, I agree that the L ibrary sha l l make i t f r ee l y ava i lab le for reference and study. I fur ther agree that permission for extensive copying of th i s thes is for scho la r l y purposes may be granted by the Head of my Department or by his representat ives . It is understood that copying or pub l i ca t ion of th is thes is fo r f inanc ia l gain sha l l not be allowed without my wri t ten permission. Department of Zoology The Univers i ty of B r i t i s h Columbia Vancouver 8, Canada Date October 26. 1970 i i ABSTRACT ' R e p r o d u c t i o n and p r o d u c t i v i t y o f t h e c o l l a r e d p e c c a r y , D i c o t y l e s t a j a c u a n g u l a t u s , were examined i n Texas under m o i s t and d r a u g h t c o n d i t i o n s , and i n c a p t i v i t y under presumed o p t i m a l c o n d i t i o n s . F o e t a l s e x r a t i o s f a v o u r f e m a l e s , l a u t change t o f a v o u r males s h o r t -I y a f t e r b i r t h , and a g a i n f a v o u r f e m a l e s i n t h e o l d e r age c l a s s e s . The s o u t h Texas p o p u l a t i o n c o n t a i n e d a h i g h e r p r o p o r t i o n o f o l d e r a n i m a l s t h a n t h e west Texas p o p u l a t i o n . L i f e e x p e c t a n c y a t 1 y e a r o f age was e s t i m a t e d a t 3.0 y e a r s i n s o u t h Texas p e c c a r i e s , a n d t h e a v e r a g e a n n u a l m o r t a l i t y r a t e was 21.5°/o. z The m o r t a l…
has type: Thesis/Dissertation
is shown at: 10.14288/1.0102164
language: eng
degree discipline: Zoology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/34781