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Orienting to polarized light at night - matching lunar skylight to performance in a nocturnal beetle

Foster, James J. LU ; Kirwan, John D. LU ; El Jundi, Basil LU ; Smolka, Jochen LU ; Khaldy, Lana LU ; Baird, Emily LU ; Byrne, Marcus J.; Nilsson, Dan Eric LU ; Johnsen, Sönke and Dacke, Marie LU (2019) In The Journal of experimental biology 222.
Abstract

For polarized light to inform behaviour, the typical range of degrees of polarization observable in the animal's natural environment must be above the threshold for detection and interpretation. Here, we present the first investigation of the degree of linear polarization threshold for orientation behaviour in a nocturnal species, with specific reference to the range of degrees of polarization measured in the night sky. An effect of lunar phase on the degree of polarization of skylight was found, with smaller illuminated fractions of the moon's surface corresponding to lower degrees of polarization in the night sky. We found that the South African dung beetle Escarabaeus satyrus can orient to polarized light for a range of degrees of... (More)

For polarized light to inform behaviour, the typical range of degrees of polarization observable in the animal's natural environment must be above the threshold for detection and interpretation. Here, we present the first investigation of the degree of linear polarization threshold for orientation behaviour in a nocturnal species, with specific reference to the range of degrees of polarization measured in the night sky. An effect of lunar phase on the degree of polarization of skylight was found, with smaller illuminated fractions of the moon's surface corresponding to lower degrees of polarization in the night sky. We found that the South African dung beetle Escarabaeus satyrus can orient to polarized light for a range of degrees of polarization similar to that observed in diurnal insects, reaching a lower threshold between 0.04 and 0.32, possibly as low as 0.11. For degrees of polarization lower than 0.23, as measured on a crescent moon night, orientation performance was considerably weaker than that observed for completely linearly polarized stimuli, but was nonetheless stronger than in the absence of polarized light.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Polarization, Sky compass, Straight-line orientation, Vision
in
The Journal of experimental biology
volume
222
publisher
The Company of Biologists Ltd
external identifiers
  • scopus:85060642407
ISSN
1477-9145
DOI
10.1242/jeb.188532
language
English
LU publication?
yes
id
2ac98a85-5336-4287-b71b-c79b130d5d22
date added to LUP
2019-02-05 10:02:44
date last changed
2019-03-05 04:31:37
@article{2ac98a85-5336-4287-b71b-c79b130d5d22,
  abstract     = {<p>For polarized light to inform behaviour, the typical range of degrees of polarization observable in the animal's natural environment must be above the threshold for detection and interpretation. Here, we present the first investigation of the degree of linear polarization threshold for orientation behaviour in a nocturnal species, with specific reference to the range of degrees of polarization measured in the night sky. An effect of lunar phase on the degree of polarization of skylight was found, with smaller illuminated fractions of the moon's surface corresponding to lower degrees of polarization in the night sky. We found that the South African dung beetle Escarabaeus satyrus can orient to polarized light for a range of degrees of polarization similar to that observed in diurnal insects, reaching a lower threshold between 0.04 and 0.32, possibly as low as 0.11. For degrees of polarization lower than 0.23, as measured on a crescent moon night, orientation performance was considerably weaker than that observed for completely linearly polarized stimuli, but was nonetheless stronger than in the absence of polarized light.</p>},
  author       = {Foster, James J. and Kirwan, John D. and El Jundi, Basil and Smolka, Jochen and Khaldy, Lana and Baird, Emily and Byrne, Marcus J. and Nilsson, Dan Eric and Johnsen, Sönke and Dacke, Marie},
  issn         = {1477-9145},
  keyword      = {Polarization,Sky compass,Straight-line orientation,Vision},
  language     = {eng},
  month        = {01},
  publisher    = {The Company of Biologists Ltd},
  series       = {The Journal of experimental biology},
  title        = {Orienting to polarized light at night - matching lunar skylight to performance in a nocturnal beetle},
  url          = {http://dx.doi.org/10.1242/jeb.188532},
  volume       = {222},
  year         = {2019},
}