AUTHORS: Samantha Dennis, Stephen Blake, Saint Louis University; Stella Uiterwaal, Elizabeth Carlen, Washington University; Zachary Reyes, Saint Louis University, Sabrina Hardy, Purdue University
ABSTRACT: Urban expansion in the Midwest poses significant challenges to wildlife habitats vital to supporting biodiversity. As cities grow, green spaces within urban environments can become important habitat refugia for numerous species. Urban parks often provide mosaics of semi-natural habitats in a matrix of high human use areas within which some native wildlife species may persist. In the midwestern US, the conservation value of urban parks for small mammal communities is poorly understood. We studied the abundance and diversity of small rodent populations in iconic Forest Park, St. Louis, in which habitat restoration has been underway for a decade. We hypothesized that small mammal abundance and diversity would be correlated with restoration effort. Over three months in summer 2024, we used live trapping methods to capture rodents and survey tree and understory vegetation across the restoration gradient of the park. We identified captured mammals to species and sex, collected morphometric data and collected hair and scat samples to characterize diets through stable isotope analysis. We completed 1,646 traps nights capturing 94 individuals. Rodent diversity was extremely low; ninety of the individuals captured were Peromyscus spp. (Deer mice), two Sciurus carolinensis (Eastern gray squirrel), one Tamias striatus (Eastern chipmunk), and 1 Didelphis virginiana (Virginia opossum). Our results showed that older restoration sections with the highest plant density and diversity supported a greater abundance of rodents than younger restoration sections with correspondingly lower plant density and diversity. While restoration duration was correlated with the abundance of small native rodents, it had no effect on rodent diversity. We speculate this may be due to dispersal limitation through the cityscape. Effective restoration management is essential to ensure that the wildlife inhabiting these areas is not only surviving but thriving, providing insights for enhancing biodiversity a long-term sustainability in urban green spaces.
