, Volume 132, Issue 1, pp 77-86

The influence of moth hearing on bat echolocation strategies

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Summary

The ears of moths we tested in Canada and Côte d'Ivoire are most sensitive to sounds between 20 and 40 kHz, and much less sensitive to sound over 65 kHz. The insectivorous bats most commonly encountered in these (and other) locations use high intensity, frequency modulated echolocation calls with frequency components in the 20–40 kHz range, making them detectable by the most sensitive tympanate moths up to 40 m away. In Africa bats such as species in the Nycteridae, Megadermatidae, and some in the Hipposideridae, use low intensity calls with high frequency components, and these species are not detectable by moths at over 2 m. The hearing ability of moths may significantly influence the feeding efficiency of bats, and changes in the intensity and frequency components of bat echolocation calls can drastically reduce the range at which bats are detected, and thus the time available to the moths for evasive behaviour (Fig. 4). The use of low intensity, high frequency echolocation calls may constitute a bat counter-maneuver against insects tuned to bat calls.

We are very grateful to Heather and Bob Baser and to Marjorie Caverly who introduced us to the facilities of the Lamto Station, and to Roger Vuattoux and Jean-Luc Tournier, and the Rector of the University of Abidjan who permitted us to use the facilities there. We thank David H.M. Cumming and the Department of National Parks and Wild Life Management of Rhodesia for allowing us to use the facilities at Sengwa, Raleigh J. Robertson for permitting us to work at the Queen's Biology Station, and Vincent Roth for permission to work at the Southwest Research Station. We are especially grateful to the personnel at all of these stations for assisting us in the field. Gary P. Bell and Donald W. Thomas assisted with some of the field work, and T.H. Kunz, A. Michelson, L.H. Miller and D.W. Thomas made valuable comments about this manuscript. Eugene Munroe of the Biosystematics Institute of Agriculture Canada, and Allan Watson of the British Museum (Natural History) assisted us with the identification of the Ivorian moths; voucher specimens of the Ivorian moths are in the British Museum (Natural History), while those for the Ivorian bats are in the collection of the Department of Mammalogy, Royal Ontario Museum. The research was supported by National Research Council of Canada operating and equipment grants to MBF, and by a National Research Council of Canada postgraduate scholarship to JHF.