Format

Send to

Choose Destination
Curr Biol. 2019 Apr 22;29(8):1369-1373.e3. doi: 10.1016/j.cub.2019.03.002. Epub 2019 Apr 4.

Experienced Migratory Bats Integrate the Sun's Position at Dusk for Navigation at Night.

Author information

1
Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany; AG Verhaltensbiologie, Institute of Biology, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany. Electronic address: lindecke@izw-berlin.de.
2
Institute of Biology, University of Latvia, Miera Street 3, 2169 Salaspils, Latvia.
3
School of Natural Sciences, Bangor University, Bangor, Gwynedd LL57 2UW, UK.
4
Faculty of Veterinary Medicine, Latvia University of Life Sciences and Technologies, K. Helmana Street 8, 3004 Jelgava, Latvia.
5
Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany; AG Verhaltensbiologie, Institute of Biology, Freie Universität Berlin, Takustraße 6, 14195 Berlin, Germany.

Abstract

From bats to whales, millions of mammals migrate every year. However, their navigation capacity for accomplishing long-distance movements remains remarkably understudied and lags behind by five decades compared to other animals [1, 2]-partly because, unlike for other taxa, such as birds and sea turtles, no small-scale orientation assay has so far been developed. Yet recently, bats became a model to investigate which cues mammals use for long-range navigation, and, surprisingly for nocturnal animals, sunset cues, and particularly polarized-light cues, appear to be crucial for calibration of the magnetic-compass system in non-migratory bats [3-5]. This does not appear to hold for a species of migratory bat, however [6], and thus the nature of the information used by migratory bats for navigation remains unclear. Here, we asked whether the position of the solar disk per se is relevant for compass orientation in a migratory bat, Pipistrellus pygmaeus. Using a new experimental assay that measures takeoff orientation, we tested the orientation of bats exposed to a shifted sunset azimuth using a mirror at dusk. Bats exposed to a 180°-rotated azimuth of the setting sun and released after translocation during the same night shifted their heading direction by ∼180° compared to control bats. However, first-year migrants had no clear orientation either as controls or after the same treatment. This suggests that learning the migratory direction is a key component in the navigational system of naive bats in this species. Our study provides rare evidence for the specific cues and mechanisms that migratory mammals use for navigation.

KEYWORDS:

animal migration; bats; compass calibration; magnetoreception; navigation; orientation; solar orientation; takeoff behavior

PMID:
30955934
DOI:
10.1016/j.cub.2019.03.002

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center