| Publication Type: | Journal Article |
| Year of Publication: | 2003 |
| Authors: | M. C. Schoeman, Jacobs D. S. |
| Journal: | Oecologia |
| Volume: | 134 |
| Pagination: | 154-162 |
| Date Published: | 2003 |
| Keywords: | [Cistugo] Myotis lesueuri, [Neoromicia] Eptesicus capensis, Chiroptera, Cistugidae, Eptesicus hottentotus, Miniopteridae, Miniopterus schreibersii, Molossidae, Myotis tricolor, Nycteridae, Nycteris thebaica, Rhinolophidae, Rhinolophus clivosus, Sauromys petrophilus, South Africa, Tadarida aegyptiaca, Vespertilionidae |
| Abstract: | {The allotonic frequency hypothesis proposes that certain insectivorous bat species can prey upon moths that can hear bat echolocation calls by using echolocation frequencies outside the sensitivity range of moth ears. The hypothesis predicts that the peak frequencies of bat echolocation calls are correlated with the incidence of moths in the diets of these bats. The aim of this study was to test this prediction on a bat community dominated by bats using low duty cycle echolocation calls, i.e. aerial foraging, insectivorous species using frequency modulated calls. The community consisted of nine species, two molossids, Sauromys petrophillus and Tadarida aegyptiaca, five vespertilionids, Eptesicus capensis, Eptesicus hottentotus, Miniopteris schreibersii, Myotis tricolor, and Myotis lesueuri, one rhinolophid, Rhinolophus clivosus, and one nycterid, Nycteris thebaica. The insect fauna in the habitat used by the bat community was suited to the testing of the allotonic frequency hypothesis because more than 90% of the moths comprising the insect fauna were tympanate. These included Pyralidae (3.8%), Geometridae (44.9%), Notodontidae (3.8%), Arctiidae (4.6%), Lymantriidae (0.8%) and Noctuidae (32.4%). As predicted, peak echolocation frequency was correlated with the incidence of moths in the diets of these nine species (r=0.98 |