Seasonal Use of Lepidopteran Prey by Rafinesque's Big-eared Bats (Corynorhinus rafinesquii)

Abstract

We examined seasonal patterns in lepidopteran prey of Rafinesque's big-eared bat (Corynorhinus rafinesquii) by collecting culled moth wings from March to September 1998 from the floor of the entrance room to a sandstone cave used as a roosting site by a maternity colony. We identified 22 species and 6 families (Arctiidae, Geometridae, Megalopygidae, Noctuidae, Notodontidae and Sphingidae) in the diet of C. rafinesquii from 135 identifiable wings recovered from the cave floor. Twelve wings comprising >2 species of moths of the family Arctiidae were recovered, indicating that C. rafinesquii periodically preys on arctiids. Abundance of culled wings was highest from 24 May to 25 July. Mean wingspan of moth prey did not vary across seasons. We observed C. rafinesquii feeding at the entrance to the roost by gleaning moths from the walls and ceiling of the cave and by capturing moths directly in flight, confirming that this species does use more than one foraging strategy in capturing moth prey.