A comparison of the roosting and foraging behaviour of three species of African insectivorous bats (Rhinolophidae, Vespertilionidae, and Molossidae)

Abstract

We used radio tracking to study the roosting and foraging behaviour of Rhinolophus hildebrandti, Scotophilus borbonicus (=S. viridis and S. leucogaster), and Tadarida midas in the Pafuri Region of Kruger National Park, South Africa in November 1985. Although the species roosted in different locations (S. borbonicus in hollow mopane trees, R. hildebrandti in a hollow baobab tree, and T. midas in buildings), roost temperatures and the bats' body temperatures were generally similar. The S. borbonicus and T. midas flew continuously while foraging in pursuit of flying prey; the R. hildebrandti switched between continuous flight, and hunting from a perch also in pursuit of flying prey. All three species foraged for about 60 min nightly, but the T. midas ventured at least 10 km from their roosts, while for S. borbonicus and R. hildebrandti, comparable figures were 4 and 2 km, respectively. The three species showed a spectrum of wing morphology and echolocation call design features from clutter resistant (R. hildebrandti) to relatively clutter resistant (S. borbonicus) and clutter intolerant (T. midas) and the foraging areas used by the bats corresponded to these features. Rhinolophus hildebrandti foraged below the canopy in riverine forest and deciduous woodland, while S. borbonicus foraged around the canopy but not closer than 0.5 m to it, while T. midas foraged in the open well above the canopy. These differences are discussed along with variations in foraging behaviour in insectivorous bats.