Shrublands act as refugia against the mammal community homogenization driven by urbanization, agriculture, and ungulate browsing

The American Midwest has been at the forefront of urban and agricultural land conversion in the last century, which has dramatically eroded biodiversity and altered mammal community assemblages. To compare the effects of ecological drivers on the characteristics of mammal communities in this landscape, we used a statewide camera-trapping network deployed between autumn and spring for three years in Illinois. We used linear and generalized additive models for location, scale, and shape, ordination, and nestedness temperature analysis to determine drivers of mammal diversity and community composition across >160 sites. We found a nuanced relationship between mammal diversity and urbanization, with impervious surface reducing richness and diversity, while human footprint increased diversity. White-tailed deer (Odocoileus virginianus) and agricultural land cover were associated with reduced community evenness and more unstructured communities, while shrubland cover had positive effects on richness, evenness, and diversity. We did not find strong support for the negative effects of coyotes (Canis latrans) on mammal diversity, likely because suppressive effects from coyotes are largely limited to sympatric canids. Our results highlight the complex relationships between mammal communities and anthropogenic expansion, while demonstrating that ecological processes such as herbivory can play an important role in shaping mammal communities. Successfully conserving mammalian diversity, therefore, may require ungulate population management in addition to preserving natural habitat, including undervalued habitat such as shrubland.