mice morphology and invasive plants dataset

Urban forest patches provide important refuges for wildlife, however, the quality of habitat provided by these forest patches may be influenced by urban conditions. Urbanization can influence the composition and structure of vegetation within forest patches, affecting the quality of trophic resources and shelter for species. In addition, urban development in the landscape surrounding forest patches can impede species’ movement between patches, further influencing habitat quality. Understanding how species respond to variation in habitat quality is especially important for species that contribute to ecosystem services for urban residents. To assess habitat quality, we examined variation in vegetation composition and structure in forest patches across a gradient of landscape-scale urban development in and around Philadelphia, PA, USA. We focused on shifts in vegetation composition and structure associated with invasive understory shrubs given their prevalence in our study system. We then quantified the numerical and morphological responses of white-footed mice (<i>Peromyscus leucopus</i>) to variation in habitat quality, because they are one of the key reservoirs for Lyme disease whose prevalence affects disease dilution ecosystem services provided by mammal communities. While we observed no significant effects of environmental variables on mice abundance in forest patches, environmental variables associated with vegetation structure, composition and landscape context all were associated with shifts in mouse morphology. Most notably, mice were larger at sites with more invasive shrub species. This indicates that invasive understory shrubs may be creating higher quality habitat for white-footed mice. Since larger bodied mice likely feed more ticks, this result has significant implications for Lyme disease dynamics in urban areas.