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Dynamics of the echolocation beam during prey pursuit in aerial hawking bats.

Jakobsen, Lasse LU ; Olsen, Mads Nedergaard and Surlykke, Annemarie (2015) In Proceedings of the National Academy of Sciences 112(26). p.8118-8123
Abstract
In the evolutionary arms race between prey and predator, measures and countermeasures continuously evolve to increase survival on both sides. Bats and moths are prime examples. When exposed to intense ultrasound, eared moths perform dramatic escape behaviors. Vespertilionid and rhinolophid bats broaden their echolocation beam in the final stage of pursuit, presumably as a countermeasure to keep evading moths within their "acoustic field of view." In this study, we investigated if dynamic beam broadening is a general property of echolocation when catching moving prey. We recorded three species of emballonurid bats, Saccopteryx bilineata, Saccopteryx leptura, and Rhynchonycteris naso, catching airborne insects in the field. The study shows... (More)
In the evolutionary arms race between prey and predator, measures and countermeasures continuously evolve to increase survival on both sides. Bats and moths are prime examples. When exposed to intense ultrasound, eared moths perform dramatic escape behaviors. Vespertilionid and rhinolophid bats broaden their echolocation beam in the final stage of pursuit, presumably as a countermeasure to keep evading moths within their "acoustic field of view." In this study, we investigated if dynamic beam broadening is a general property of echolocation when catching moving prey. We recorded three species of emballonurid bats, Saccopteryx bilineata, Saccopteryx leptura, and Rhynchonycteris naso, catching airborne insects in the field. The study shows that S. bilineata and S. leptura maintain a constant beam shape during the entire prey pursuit, whereas R. naso broadens the beam by lowering the peak call frequency from 100 kHz during search and approach to 67 kHz in the buzz. Surprisingly, both Saccopteryx bats emit calls with very high energy throughout the pursuit, up to 60 times more than R. naso and Myotis daubentonii (a similar sized vespertilionid), providing them with as much, or more, peripheral "vision" than the vespertilionids, but ensonifying objects far ahead suggesting more clutter. Thus, beam broadening is not a fundamental property of the echolocation system. However, based on the results, we hypothesize that increased peripheral detection is crucial to all aerial hawking bats in the final stages of prey pursuit and speculate that beam broadening is a feature characterizing more advanced echolocation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
perception, buzz, echolocation, bat, directionality
in
Proceedings of the National Academy of Sciences
volume
112
issue
26
pages
8118 - 8123
publisher
National Acad Sciences
external identifiers
  • wos:000357079400065
  • pmid:26080398
  • scopus:84937882854
ISSN
1091-6490
DOI
10.1073/pnas.1419943112
language
English
LU publication?
yes
id
21d6544a-6513-4bce-a2ec-06dec3a82d8d (old id 7485550)
date added to LUP
2015-07-23 08:18:44
date last changed
2017-05-28 03:22:04
@article{21d6544a-6513-4bce-a2ec-06dec3a82d8d,
  abstract     = {In the evolutionary arms race between prey and predator, measures and countermeasures continuously evolve to increase survival on both sides. Bats and moths are prime examples. When exposed to intense ultrasound, eared moths perform dramatic escape behaviors. Vespertilionid and rhinolophid bats broaden their echolocation beam in the final stage of pursuit, presumably as a countermeasure to keep evading moths within their "acoustic field of view." In this study, we investigated if dynamic beam broadening is a general property of echolocation when catching moving prey. We recorded three species of emballonurid bats, Saccopteryx bilineata, Saccopteryx leptura, and Rhynchonycteris naso, catching airborne insects in the field. The study shows that S. bilineata and S. leptura maintain a constant beam shape during the entire prey pursuit, whereas R. naso broadens the beam by lowering the peak call frequency from 100 kHz during search and approach to 67 kHz in the buzz. Surprisingly, both Saccopteryx bats emit calls with very high energy throughout the pursuit, up to 60 times more than R. naso and Myotis daubentonii (a similar sized vespertilionid), providing them with as much, or more, peripheral "vision" than the vespertilionids, but ensonifying objects far ahead suggesting more clutter. Thus, beam broadening is not a fundamental property of the echolocation system. However, based on the results, we hypothesize that increased peripheral detection is crucial to all aerial hawking bats in the final stages of prey pursuit and speculate that beam broadening is a feature characterizing more advanced echolocation.},
  author       = {Jakobsen, Lasse and Olsen, Mads Nedergaard and Surlykke, Annemarie},
  issn         = {1091-6490},
  keyword      = {perception,buzz,echolocation,bat,directionality},
  language     = {eng},
  number       = {26},
  pages        = {8118--8123},
  publisher    = {National Acad Sciences},
  series       = {Proceedings of the National Academy of Sciences},
  title        = {Dynamics of the echolocation beam during prey pursuit in aerial hawking bats.},
  url          = {http://dx.doi.org/10.1073/pnas.1419943112},
  volume       = {112},
  year         = {2015},
}