Around 1000 species of bats in the world use echolocation to navigate, orient, and detect insect prey. Many of these bats emerge from their roost at dusk and start foraging when there is still light available. It is however unclear in what way and to which extent navigation, or even prey detection in these bats is aided by vision. Here we compare the echolocation and visual detection ranges of two such species of bats which rely on different foraging strategies (Rhinopoma microphyllum and Pipistrellus kuhlii). We find that echolocation is better than vision for detecting small insects even in intermediate light levels (1–10 lux), while vision is advantageous for monitoring far-away landscape elements in both species. We thus hypothesize that, bats constantly integrate information acquired by the two sensory modalities. We suggest that during evolution, echolocation was refined to detect increasingly small targets in conjunction with using vision. To do so, the ability to hear ultrasonic sound is a prerequisite which was readily available in small mammals, but absent in many other animal groups. The ability to exploit ultrasound to detect very small targets, such as insects, has opened up a large nocturnal niche to bats and may have spurred diversification in both echolocation and foraging tactics.
Keywords: yinpterochiroptera, yangochiroptera, FoxP2, swiftlet, oilbird, pteropodidae, hearing gene, eocene
Citation: Boonman A, Bar-On Y, Cvikel N and Yovel Y (2013) It's not black or white—on the range of vision and echolocation in echolocating bats. Front. Physiol. 4:248. doi: 10.3389/fphys.2013.00248
Received: 07 March 2013; Accepted: 22 August 2013;
Published online: 11 September 2013.
Edited by:Mariana L. Melcón, Fundación Cethus, Argentina
Reviewed by:Shizuko Hiryu, Doshisha University, Japan
Copyright © 2013 Boonman, Bar-On, Cvikel and Yovel. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Arjan Boonman, Department of Zoology, University of Tel Aviv, Klausner Street, PO Box 39040, Tel Aviv 6997801, Israel e-mail: firstname.lastname@example.org
†These authors have contributed equally to this work.