Modelling the effects of social variation on population dynamics for group-living primates /
PRIMATES, a stochastic simulation model containing interacting groups, was developed to characterize the effects of environmental, demographic and social variation on small populations of female philopatric primates. Model outcomes are affected by manipulations at three levels of variation: environm...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=730298351&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | PRIMATES, a stochastic simulation model containing interacting groups, was developed to characterize the effects of environmental, demographic and social variation on small populations of female philopatric primates. Model outcomes are affected by manipulations at three levels of variation: environmental variation, caused by changes in resource availability and interpopulation immigration', demographic variation, represented by age-, sex-, and reproductive state- related differences in birth, death and migration rates; and social variation, resulting from intragroup and intergroup dominance hierarchies, differences in competitive abilities, and consequences of behavioral interactions. Comparisons were made between 100-year simulation outcomes under each of four PRIMATES model versions including different aspects of social variation -- intragroup, intergroup, both intragroup and intergroup, and no social variation. Fifty replicate simulations using each model version were run under each of four environmental scenarios. Indices of population variation between model versions and environmental scenarios were compared using ANOVA and post hoc tests of means. Primate populations simulated with social variation exhibited significantly different population size averages, minima, maxima, and annual variation over nonsocial populations under all environmental scenarios 1<0.01, all cases). Populations having only intergroup social variation showed greater differences from nonsocial populations than those containing only intragroup social variation. Unstable group hierarchies in populations having only intergroup variation caused population growth rate declines, and increased extinction risk over nonsocial populations (p <0.01). Results support hypotheses stating that social and behavioral variation, particularly between groups, strongly influence population dynamics for group-living primates. Adding individual variation resulted in more stable intragroup dominance hierarchies, and improved population growth and extinction risk measures, primarily through reduced mortality. By limiting some individuals' access to resources, certain population segments maintained high reproductive rates, even during resource shortages. Individuals temporarily unable to reproduce, survived until improved conditions permitted resumption of reproductive activities. Results support hypotheses asserting group living provides a selective advantage in defense against intruders, while stable linear intragroup dominance hierarchies serve to minimize negative consequences resulting from intergroup competition. Results suggest that large reserve sizes and habitat connectivity permitting exchange of mixed-sex groups, rather than individually dispersing males, are critical to female-philopatric primate conservation. |
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| Item Description: | Vita. "Major Subject: Wildlife and Fisheries Sciences". |
| Physical Description: | xi, 162 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (147-161). |