A comparison of foraging by <i>Eptesicus fuscus</i> (Chiroptera: Vespertilionidae) in urban and rural environments

Differences in foraging rates and the fact that rural bats spent significantly less time away from their roosts suggest that prey density was lower in the urban setting.

Abstract

We compared the foraging activity of populations of Eptesicus fuscus in rural and urban settings in eastern Ontario and western Quebec by monitoring their echolocation calls and by radio tracking individuals during the summer of 1980. Foraging was detected in all of the rural and urban habitats we monitored. There were no significant differences in the levels of foraging activity over different urban habitats, but the overall foraging rates were significantly higher in the rural than in the urban areas. Foraging in rural areas was significantly higher in residential zones and over water and was less common in parkland and farmland. Bats in rural areas foraged among aggregations of insects at lights, a pattern of behaviour not seen among urban bats. Differences in foraging rates and the fact that rural bats spent significantly less time away from their roosts suggest that prey density was lower in the urban setting. Although urban habitats appear to provide E. fuscus with a wealth of roosting sites, food supplies are lower there.