Habitat exploitation by a gleaning bat,Plecotus auritus

Abstract

The brown long-eared bat,Plecotus auritus, differs from most other Palaearctic bats in having broad wings and long ears, which are linked to its slow flight, and its ability to hover and thus glean insects from surfaces. Previous studies have suggested a relation between interspecific variation in morphology of bats, particularly the shape of the wing, and differences in foraging behaviour. It might be predicted therefore that the foraging behaviour ofP. aurituswould differ from other Palaearctic species that have been studied. To examine activity patterns and habitat use, 16P. aurituswere radio-tracked from six roost sites in northeast Scotland. Differences in behaviour compared to other Palaearctic species were found in the nocturnal activity pattern, habitat use and distance travelled to foraging areas.Plecotus auritusemerged later than other sympatric species, at around 55 min after sunset, and remained active throughout the night, with a generally unimodal activity pattern. Individual bats used a series of feeding sites, to which they returned regularly, and sometimes shared with others from the same roost.Plecotus auritusforaged exclusively in woodland and around individual trees. The bats displayed a preference for deciduous over coniferous woodland, probably reflecting higher insect availability in the former. Hedgerows, tree lines and fence lines were used as commuting routes between roosts and feeding sites. Bats travelled up to 2.8 km from the roost site, but spent most time foraging within 0.5 km of the roost, although males foraged further from the roost than females. The foraging behaviour ofP. auritusreflected the morphological specializations of this species, but displayed a degree of intraspecific flexibility. Deciduous woodland in the vicinity of roost sites appeared to be key foraging habitat forP. auritus.