Habitat preference and overnight and seasonal variation in the foraging activity of lesser horseshoe bats

The ultrasonic foraging pulses of the lesser horseshoe bat Rhinolophus hipposideros (Bechstein, 1800) were monitored repeatedly at night from May to September for sample periods of 15 min at a variety of sites in two districts in western Ireland, predominantly of permanent pasture. Pulses were commonest by water and over farmyards, less frequent along trees and hedgerows, and relatively rare over open pasture. Feeding activity decreased overnight, although bats were still active before dawn, and also increased towards the end of the summer. The possible reasons for these spatial and temporal feeding patterns are discussed.