Whitman Daniel A, Werdel Ty J
Department of Biology Macalester College Saint Paul Minnesota USA.
Department of Rangeland, Wildlife, and Fisheries Management Texas A&M University College Station Texas USA.
Ecol Evol. 2024 Oct 27;14(10):e70488. doi: 10.1002/ece3.70488. eCollection 2024 Oct.
Urbanization and urban sprawl generally degrade and diminish wildlife habitat, threatening to extirpate local populations. However, certain synanthropic species (e.g., coyotes, white-tailed deer, and squirrels) are able to persist in urban environments and may even occur at greater densities than they do in their natural habitats. Eastern fox squirrels () are large tree squirrels that are known to be present in greater densities within urban areas. To determine how landscape characteristics may affect fox squirrel presence, we conducted line-transect surveys along sidewalks on the Texas A&M University-College Station campus to record presence of fox squirrels and nearest tree species. We calculated Jacobs' index of selectivity () for use of trees by fox squirrels along the transects. Squirrel density was calculated for all transects and modeled using linear regression with environmental (e.g., tree density) and survey (e.g., transect distance) variables. Fox squirrels preferred only a small number of the available tree species, primarily and species. Observed fox squirrel density significantly increased with time of day, temperature, density of oaks ( spp.), and density of all trees, and decreased with distance and area of the transect. These results suggest that even when urban areas contain suitable habitat, use of urban environments by wildlife is still highly selective and dependent on specific habitat requirements.
城市化和城市扩张通常会破坏并减少野生动物栖息地，威胁到当地种群的灭绝。然而，某些伴人物种（如郊狼、白尾鹿和松鼠）能够在城市环境中生存，甚至其密度可能比在自然栖息地中还要高。东部狐松鼠（ ）是大型树松鼠，已知在城市地区的密度更高。为了确定景观特征如何影响狐松鼠的出现情况，我们在德克萨斯农工大学大学城校区的人行道上进行了样线调查，以记录狐松鼠的出现情况和最近的树种。我们计算了狐松鼠在样线上对树木利用的雅各布斯选择性指数（ ）。计算了所有样线的松鼠密度，并使用环境（如树木密度）和调查（如样线距离）变量进行线性回归建模。狐松鼠只偏爱少数几种可用的树种，主要是 和 物种。观察到的狐松鼠密度随时间、温度、橡树（ 属物种）密度和所有树木的密度显著增加，随样线的距离和面积减小。这些结果表明，即使城市地区包含适宜的栖息地，野生动物对城市环境的利用仍然具有高度选择性，并依赖于特定的栖息地要求。
