Behavioral Responses of Eastern Gray Squirrels in Suburban Habitats Differing in Human Activity Levels

We observed the alert responses of Sciurus carolinensis (Eastern Gray Squirrel) to two different approach stimuli (human only and human with a leashed (log) in two suburban habitats differing in the level of human activity. Alert distance in the habitat with higher levels of human activity was significantly shorter than the alert distance in the habitat with lower levels of human activity. Overall, the alert distance did not differ between the approach by a human alone and the approach by a human with a dog; however, in the high human activity sites (but not the low human activity sites), the presence of the dog increased alert distance in the squirrels. In addition, squirrels tended to initially respond by running more in the high human activity sites, but the presence of the dog increased the number of squirrels whose initial responses were to not run. Our results suggest that Eastern Gray Squirrel antipredator behavior, at least in response to humans and hunian-associated animals, is influenced by the level of human activity in the surrounding habitat.