Dirk Van Vuren, Ph.D.

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Research Project Abstract 

Title-Spatial organization and demography of golden-mantled ground squirrels

The demography of ground-dwelling squirrels, particularly reproduction and survival, may be influenced by both intrinsic and extrinsic factors. Intrinsic influences result from their spatial organization. Most ground-dwelling squirrels live in social groups comprised of related females; females cooperate in predator defense, thereby enhancing survival, but competition for resources among crowded females may depress reproduction. 

Extrinsic factors include the availability of food in the form of herbaceous vegetation. I am studying spatial organization and demography of the golden-mantled ground squirrel, considered a nonsocial species. The species has not been studied, but females are believed to live alone in home ranges that do not overlap, presumably denying them the benefits of sociality. However, these solitary females may obtain some of these benefits; I suspect that some females live adjacent to close relatives, sharing some space and exhibiting some degree of cooperation, with resultant demographic benefits.

 Further, my expectation is that survival and reproduction will be affected by the time of snowmelt each spring, which determines growth of herbaceous vegetation, and perhaps by amount of summer rainfall.