College squirrels gone wild? Using Sciurus carolinensis behavior to assess the ecosystem value of urban green spaces

Abstract

Predicted rapid increases in urbanization in the face of accelerating biodiversity loss underscores the need for urban development that promotes rather than displaces native plants and animals. One approach for increasing urban biodiversity is through the development of "green infrastructure". Although research has explored urban-rural gradients and the overall value of urban green infrastructure, few studies have investigated the habitat value for wildlife of different types of urban greenspace. Here, we use a well-established metric in ecology, giving up-densities (GUDs), to compare foraging costs for a common urban wildlife species, the eastern gray squirrel (Sciurus carolinensis), among three green infrastructure categories: municipal parks, college campuses, and residential yards. We found that GUDs for gray squirrels did not differ signi cantly among location categories after controlling for proximity to roads, but proximity to roads was associated with signi cantly higher GUDs in all locations. In an explicit test, we also found that both proximity to roads and tra c volume were associated with higher GUDs. We also found that maximum distance from roads was signi cantly higher for campuses and parks than for residential yards, indicating a greater proportion of the area of campuses and parks is "away from roads" compared to residential yards. Our results indicate that vehicle tra c may contribute signi cantly to an "urban landscape of fear" for gray squirrels and suggest that campus and park con gurations that reduce road effects could improve habitat quality for squirrels and possibly other animals.

The impact of urbanisation on chipmunks, arboreal and flying squirrels: a global systematic review

“…GUDs were further used to assess the quality of urban spaces for eastern grey squirrels in Minnesota (Kay et al. 2023). Seed trays were located in campuses, residential yards and municipal parks to evaluate a possible difference among these three urban location types, but there was no difference in mean GUD among the three types (Kay et al.…”

“…Seed trays were located in campuses, residential yards and municipal parks to evaluate a possible difference among these three urban location types, but there was no difference in mean GUD among the three types (Kay et al. 2023). However, GUDs varied within location type depending upon proximity to roads; much more seeds were removed in sites away from roads than in sites near roads, suggesting that urban traffic/road density should be considered to improve the quality of urban green areas (Kay et al.…”

“…However, GUDs varied within location type depending upon proximity to roads; much more seeds were removed in sites away from roads than in sites near roads, suggesting that urban traffic/road density should be considered to improve the quality of urban green areas (Kay et al. 2023).…”