OPPORTUNISTIC PREDATION OF A LITTLE BROWN BAT (MYOTIS LUCIFUGUS) BY A GREAT HORNED OWL (BUBO VIRGINIANUS) IN SOUTHERN YUKON

摘要

Generally, it is believed that predation is not a significant cause of mortality for bats (Manville 1963), although this view has been challenged (Speakman 1991; Fenton and others 1994). During emergence from diurnal roosts and nocturnal foraging bouts by bats, owls are probably their chief predator (Twente 1954; Speakman 1991), and they may profoundlyinfluence bat behavior and local population dynamics. For example, in his landmark study,Speakman (1991) documented 6 species of owls preying on bats in the British Isles. He estimated that Tawny Owls (Strix aluco) alone likely killed at least 168,850 bats per annum in the British Isles. Individuals of some species of owls may specialize locally on bats, including Tawny Owls (Lesin′ ski and others 2009), Barn Owls (Tyto alba; Taylor 1964; Ruprecht 1979; Sommer and others 2009), and Black-and-White Owls (Ciccaba nigrolineata; Gerhardt and others 1994).