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Diurnal dung beetles use the intensity gradient and the polarization pattern of the sky for orientation.

el Jundi, Basil LU ; Smolka, Jochen LU ; Baird, Emily LU ; Byrne, Marcus J and Dacke, Marie LU (2014) In Journal of Experimental Biology 217(13). p.2422-2429
Abstract
To escape competition at the dung pile, a ball-rolling dung beetle forms a piece of dung into a ball and rolls it away. To ensure an their efficient escape from the dung pile, the beetles rely on a celestial compass to move along a straight paths. Here, we analyzed the reliability of different skylight cues for this compass and found that dung beetles rely not only on the sun, but also on the skylight polarization pattern. Moreover, we show the first evidence of an insect using the celestial light intensity gradient for orientation. Using a polarizer, we manipulated skylight so that the polarization pattern appeared to turn by 90°. The beetles then changed their bearing close to the expected 90°. This behavior was abolished if the sun was... (More)
To escape competition at the dung pile, a ball-rolling dung beetle forms a piece of dung into a ball and rolls it away. To ensure an their efficient escape from the dung pile, the beetles rely on a celestial compass to move along a straight paths. Here, we analyzed the reliability of different skylight cues for this compass and found that dung beetles rely not only on the sun, but also on the skylight polarization pattern. Moreover, we show the first evidence of an insect using the celestial light intensity gradient for orientation. Using a polarizer, we manipulated skylight so that the polarization pattern appeared to turn by 90°. The beetles then changed their bearing close to the expected 90°. This behavior was abolished if the sun was visible to the beetle, suggesting that polarized light is hierarchically subordinate to the sun. If the sky was depolarized and the sun was invisible, the beetles could still move along straight paths. We therefore analyzed the use of the celestial intensity gradient for orientation. Artificially rotating the intensity pattern by 180° caused beetles to orient in the opposite direction. The intensity cue was also found to be subordinate to the sun, and could play a role in disambiguating the polarization signal, especially at low sun elevations. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Experimental Biology
volume
217
issue
13
pages
2422 - 2429
publisher
The Company of Biologists Ltd
external identifiers
  • pmid:24737763
  • wos:000339272900032
  • scopus:84901665451
ISSN
1477-9145
DOI
10.1242/jeb.101154
language
English
LU publication?
yes
id
12c42fbb-624f-4de1-8425-d627b4bccea5 (old id 4429987)
date added to LUP
2014-05-08 16:02:57
date last changed
2017-04-23 03:22:09
@article{12c42fbb-624f-4de1-8425-d627b4bccea5,
  abstract     = {To escape competition at the dung pile, a ball-rolling dung beetle forms a piece of dung into a ball and rolls it away. To ensure an their efficient escape from the dung pile, the beetles rely on a celestial compass to move along a straight paths. Here, we analyzed the reliability of different skylight cues for this compass and found that dung beetles rely not only on the sun, but also on the skylight polarization pattern. Moreover, we show the first evidence of an insect using the celestial light intensity gradient for orientation. Using a polarizer, we manipulated skylight so that the polarization pattern appeared to turn by 90°. The beetles then changed their bearing close to the expected 90°. This behavior was abolished if the sun was visible to the beetle, suggesting that polarized light is hierarchically subordinate to the sun. If the sky was depolarized and the sun was invisible, the beetles could still move along straight paths. We therefore analyzed the use of the celestial intensity gradient for orientation. Artificially rotating the intensity pattern by 180° caused beetles to orient in the opposite direction. The intensity cue was also found to be subordinate to the sun, and could play a role in disambiguating the polarization signal, especially at low sun elevations.},
  author       = {el Jundi, Basil and Smolka, Jochen and Baird, Emily and Byrne, Marcus J and Dacke, Marie},
  issn         = {1477-9145},
  language     = {eng},
  number       = {13},
  pages        = {2422--2429},
  publisher    = {The Company of Biologists Ltd},
  series       = {Journal of Experimental Biology},
  title        = {Diurnal dung beetles use the intensity gradient and the polarization pattern of the sky for orientation.},
  url          = {http://dx.doi.org/10.1242/jeb.101154},
  volume       = {217},
  year         = {2014},
}