Foraging behaviour of the gleaning bat Myotis nattereri (Chiroptera, Vespertilionidae) in the Swiss Alps

The foraging behaviour of Myotis nattereri was observed in nature by using a night scope. While searching for prey over mowed meadows, Natterer's bats fly close to grass. When prey are detected in grass, the bat performs a circular hovering sequence around the prey item at close range. The prey item is then gleaned, probably by using the tail membrane and/or the feet. Prey are eaten on the wing during an undulating flight some meters above ground level. On one occasion, in a traditional orchard, a bat was observed gleaning prey from beneath the lowest tree leaves. The fringe of hairs along the edge of the interfemoral membrane of M. nattereri probably enhances tactile sensitivity during prey capture; it is suggested that this feature may have an adaptive significance not only for M. nattereri but also for other ''fringe-tailed'' Myotis species.