Visual detection threshold in the echolocating Daubenton's bat (Myotis daubentonii)
Author:
Céchetto Clément1,
Jakobsen Lasse1,
Warrant Eric J.2
Affiliation:
1. 1 Department of Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
2. 2 Department of Biology, Lund University, Biology building, Sölvegatan 35, Lund, Sweden
Abstract
All bats possess eyes that are of adaptive value. Echolocating bats have retinae dominated by rod photoreceptors and use dim light vision for navigation, and in rare cases for hunting. However, the visual detection threshold of insectivorous echolocating bats remains unknown. Here we determine this threshold for the vespertilionid bat Myotis daubentonii. We show that for a green luminous target, M. daubentonii has a visual luminance threshold of 3.2±0.9×10−4 candela/m2, an intensity corresponding to the luminance of an open cloudless terrestrial habitat on a starlit night. Our results show that echolocating bats have good visual sensitivity, allowing them to see when they are active. Together with previous results showing that M. daubentonii has poor visual acuity (∼0.6 cycles/deg), suggests that echolocating bats do not use vision to hunt but rather to orient themselves.
Funder
Danmarks Frie Forskningfond
Human frontier science program
Publisher
The Company of Biologists
Subject
Insect Science,Molecular Biology,Animal Science and Zoology,Aquatic Science,Physiology,Ecology, Evolution, Behavior and Systematics