Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer
Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is go...
Published in: | Proceedings of the Royal Society B: Biological Sciences |
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Online Access: | https://hdl.handle.net/10037/25073 https://doi.org/10.1098/rspb.2013.2451 |
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ftunivtroemsoe:oai:munin.uit.no:10037/25073 2023-05-15T14:26:41+02:00 Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer Stokkan, Karl-Arne Folkow, Lars Dukes, Juliet Neveu, Magella Hogg, Chris R Siefken, Sandra Katharina Christiane Dakin, Steven C Jeffery, Glen 2013-12-22 https://hdl.handle.net/10037/25073 https://doi.org/10.1098/rspb.2013.2451 eng eng The Royal Society Proceedings of the Royal Society of London. Biological Sciences Stokkan k.a., Folkow P., Dukes, Neveu M, Hogg CR, Siefken SKC, Dakin, Jeffery G. Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer. Proceedings of the Royal Society of London. Biological Sciences. 2013;280(1773) FRIDAID 1082059 doi:10.1098/rspb.2013.2451 0962-8452 1471-2954 https://hdl.handle.net/10037/25073 openAccess Copyright 2013 The Author(s) Journal article Tidsskriftartikkel Peer reviewed publishedVersion 2013 ftunivtroemsoe https://doi.org/10.1098/rspb.2013.2451 2022-05-11T22:58:43Z Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is golden with most light reflected back directly through the retina, whereas in winter it is deep blue with less light reflected out of the eye. The blue reflection in winter is associated with significantly increased retinal sensitivity compared with summer animals. The wavelength of reflection depends on TL collagen spacing, with reduced spacing resulting in shorter wavelengths, which we confirmed in summer and winter animals. Winter animals have significantly increased intra-ocular pressure, probably produced by permanent pupil dilation blocking ocular drainage. This may explain the collagen compression. The resulting shift to a blue reflection may scatter light through photoreceptors rather than directly reflecting it, resulting in elevated retinal sensitivity via increased photon capture. This is, to our knowledge, the first description of a retinal structural adaptation to seasonal changes in environmental light. Increased sensitivity occurs at the cost of reduced acuity, but may be an important adaptation in reindeer to detect moving predators in the dark Arctic winter. Article in Journal/Newspaper Arctic Arctic University of Tromsø: Munin Open Research Archive Arctic Proceedings of the Royal Society B: Biological Sciences 280 1773 20132451 |
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Open Polar |
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University of Tromsø: Munin Open Research Archive |
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ftunivtroemsoe |
language |
English |
description |
Arctic reindeer experience extreme changes in environmental light from continuous summer daylight to continuous winter darkness. Here, we show that they may have a unique mechanism to cope with winter darkness by changing the wavelength reflection from their tapetum lucidum (TL). In summer, it is golden with most light reflected back directly through the retina, whereas in winter it is deep blue with less light reflected out of the eye. The blue reflection in winter is associated with significantly increased retinal sensitivity compared with summer animals. The wavelength of reflection depends on TL collagen spacing, with reduced spacing resulting in shorter wavelengths, which we confirmed in summer and winter animals. Winter animals have significantly increased intra-ocular pressure, probably produced by permanent pupil dilation blocking ocular drainage. This may explain the collagen compression. The resulting shift to a blue reflection may scatter light through photoreceptors rather than directly reflecting it, resulting in elevated retinal sensitivity via increased photon capture. This is, to our knowledge, the first description of a retinal structural adaptation to seasonal changes in environmental light. Increased sensitivity occurs at the cost of reduced acuity, but may be an important adaptation in reindeer to detect moving predators in the dark Arctic winter. |
format |
Article in Journal/Newspaper |
author |
Stokkan, Karl-Arne Folkow, Lars Dukes, Juliet Neveu, Magella Hogg, Chris R Siefken, Sandra Katharina Christiane Dakin, Steven C Jeffery, Glen |
spellingShingle |
Stokkan, Karl-Arne Folkow, Lars Dukes, Juliet Neveu, Magella Hogg, Chris R Siefken, Sandra Katharina Christiane Dakin, Steven C Jeffery, Glen Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer |
author_facet |
Stokkan, Karl-Arne Folkow, Lars Dukes, Juliet Neveu, Magella Hogg, Chris R Siefken, Sandra Katharina Christiane Dakin, Steven C Jeffery, Glen |
author_sort |
Stokkan, Karl-Arne |
title |
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer |
title_short |
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer |
title_full |
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer |
title_fullStr |
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer |
title_full_unstemmed |
Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer |
title_sort |
shifting mirrors: adaptive changes in retinal reflections to winter darkness in arctic reindeer |
publisher |
The Royal Society |
publishDate |
2013 |
url |
https://hdl.handle.net/10037/25073 https://doi.org/10.1098/rspb.2013.2451 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Arctic |
genre_facet |
Arctic Arctic |
op_relation |
Proceedings of the Royal Society of London. Biological Sciences Stokkan k.a., Folkow P., Dukes, Neveu M, Hogg CR, Siefken SKC, Dakin, Jeffery G. Shifting mirrors: adaptive changes in retinal reflections to winter darkness in Arctic reindeer. Proceedings of the Royal Society of London. Biological Sciences. 2013;280(1773) FRIDAID 1082059 doi:10.1098/rspb.2013.2451 0962-8452 1471-2954 https://hdl.handle.net/10037/25073 |
op_rights |
openAccess Copyright 2013 The Author(s) |
op_doi |
https://doi.org/10.1098/rspb.2013.2451 |
container_title |
Proceedings of the Royal Society B: Biological Sciences |
container_volume |
280 |
container_issue |
1773 |
container_start_page |
20132451 |
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1766299982409760768 |