Browsing with burros: An analysis of the impacts of feral burros on shrub heights in San Timoteo Canyon

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wild burros, plant ecology, hillside chaparral, grassland, California, San Timoteo


Animal Sciences | Biodiversity | Biostatistics | Ecology and Evolutionary Biology | Environmental Sciences | Natural Resources and Conservation | Other Environmental Sciences | Plant Sciences | Systems Biology


Populations of feral burros have been thriving throughout the American Southwest for the past several centuries. Wherever non-native burros are found, they tend to affect local ecosystems. San Timoteo Canyon, in San Bernardino County, CA, is home to an apparently large and poorly studied population of wild burros. This study inspects the impact of browsing pressure from wild burros on shrub heights in this canyon, as well as their population and behavioral dynamics. Samples were taken by conducting plant surveys of three sites with apparent presence and absence of burros, in fifteen point centered, circular plots. Behavioral observations were conducted on a population of 47 burros. Results indicate that there is no relationship between browsing and heights of plants (factor loadings = 0.017611), but point to a significant difference in plant heights between areas inhabited and uninhabited by burros (factor loadings = 0.573302). Behavior was distributed predominately across herbivory (21.71%), browsing (6.30%), and grazing (15.41%).

Department 1 Awarding Honors Status

Environmental Studies

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