REVIEW ARTICLE published: 28 May 2013 doi: 10.3389/fphys.2013.00123 Echolocation in Oilbirds and swiftlets Signe Brinkløv 1*, M. Brock Fenton 1 and John M. Ratcliffe 2 1 Department of Biology, Western University, London, ON, Canada 2 Institute of Biology, University of Southern Denmark, Odense, Denmark Edited by: The discovery of ultrasonic bat echolocation prompted a wide search for other animal Mariana L. Melcón, Fundación biosonar systems, which yielded, among few others, two avian groups. One, the South Cethus, Argentina American Oilbird (Steatornis caripensis: Caprimulgiformes), is nocturnal and eats fruit. The Reviewed by: other is a selection of diurnal, insect-eating swiftlets (species in the genera Aerodramus Noritaka Ichinohe, National Institute of Neuroscience, Japan and Collocalia:Apodidae)fromacrosstheIndo-Pacific.Birdecholocationisrestrictedto Lore Thaler, Durham University, UK lower frequencies audible to humans, implying a system of poorer resolution than the *Correspondence: ultrasonic (>20 kHz) biosonar of most bats and toothed whales. As such, bird echolocation Signe Brinkløv, Department of has been labeled crude or rudimentary. Yet, echolocation is found in at least 16 extant Biology, Western University, bird species and has evolved several times in avian lineages. Birds use their syringes to 1151 Richmond Street, London, ON N6A 3K7, Canada. produce broadband click-type biosonar signals that allow them to nest in dark caves and e-mail:
[email protected] tunnels, probably with less predation pressure. There are ongoing discrepancies about several details of bird echolocation, from signal design to the question about whether echolocation is used during foraging. It remains to be seen if bird echolocation is as sophisticated as that of tongue-clicking rousette bats.