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Hermit crabs (Pagurus bernhardus) use visual contrast in self-assessment of camouflage

Wilby, David LU ; Riches, Samuel; Daly, Ilse M.; Bird, Andrew; Wheelwright, Matthew and Foster, James J. LU (2018) In Journal of Experimental Biology 221(13).
Abstract

Animals can make use of camouflage to reduce the likelihood of visual detection or recognition and thus improve their chances of survival. Background matching, where body colouration is closely matched to the surrounding substrate, is one form of camouflage. Hermit crabs have the opportunity to choose their camouflage independently of body colouration as they inhabit empty gastropod shells, making them ideal to study their choice of camouflage. We used 3D-printed artificial shells of varying contrasts against a grey substrate to test whether hermit crabs prefer shells that they perceive as less conspicuous. Contrast-minimising shells were chosen for Weber contrasts stronger than −0.5. However, in looming experiments, animals responded... (More)

Animals can make use of camouflage to reduce the likelihood of visual detection or recognition and thus improve their chances of survival. Background matching, where body colouration is closely matched to the surrounding substrate, is one form of camouflage. Hermit crabs have the opportunity to choose their camouflage independently of body colouration as they inhabit empty gastropod shells, making them ideal to study their choice of camouflage. We used 3D-printed artificial shells of varying contrasts against a grey substrate to test whether hermit crabs prefer shells that they perceive as less conspicuous. Contrast-minimising shells were chosen for Weber contrasts stronger than −0.5. However, in looming experiments, animals responded to contrasts as weak as −0.2, indicating that while they can detect differences between shells and the background, they are only motivated to move into those shells when the alternatives contrast strongly. This suggests a trade-off between camouflage and vulnerability introduced by switching shells.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Background matching, Colouration, Crypsis, Vision
in
Journal of Experimental Biology
volume
221
issue
13
publisher
The Company of Biologists Ltd
external identifiers
  • scopus:85049669478
ISSN
0022-0949
DOI
10.1242/jeb.173831
language
English
LU publication?
yes
id
48bec8cb-7814-4ebf-9ebc-686c3ca041e8
date added to LUP
2018-07-30 14:37:58
date last changed
2019-01-29 03:00:17
@article{48bec8cb-7814-4ebf-9ebc-686c3ca041e8,
  abstract     = {<p>Animals can make use of camouflage to reduce the likelihood of visual detection or recognition and thus improve their chances of survival. Background matching, where body colouration is closely matched to the surrounding substrate, is one form of camouflage. Hermit crabs have the opportunity to choose their camouflage independently of body colouration as they inhabit empty gastropod shells, making them ideal to study their choice of camouflage. We used 3D-printed artificial shells of varying contrasts against a grey substrate to test whether hermit crabs prefer shells that they perceive as less conspicuous. Contrast-minimising shells were chosen for Weber contrasts stronger than −0.5. However, in looming experiments, animals responded to contrasts as weak as −0.2, indicating that while they can detect differences between shells and the background, they are only motivated to move into those shells when the alternatives contrast strongly. This suggests a trade-off between camouflage and vulnerability introduced by switching shells.</p>},
  articleno    = {jeb173831},
  author       = {Wilby, David and Riches, Samuel and Daly, Ilse M. and Bird, Andrew and Wheelwright, Matthew and Foster, James J.},
  issn         = {0022-0949},
  keyword      = {Background matching,Colouration,Crypsis,Vision},
  language     = {eng},
  month        = {07},
  number       = {13},
  publisher    = {The Company of Biologists Ltd},
  series       = {Journal of Experimental Biology},
  title        = {Hermit crabs (Pagurus bernhardus) use visual contrast in self-assessment of camouflage},
  url          = {http://dx.doi.org/10.1242/jeb.173831},
  volume       = {221},
  year         = {2018},
}