Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels
In indigenous arctic reindeer and ptarmigan, circadian rhythms are not expressed during the constant light of summer or constant dark of winter, and it has been hypothesized that a seasonal absence of circadian rhythms is common to all vertebrate residents of polar regions. Here, we show that, while...
Published in: | Biology Letters |
---|---|
Main Authors: | , , |
Format: | Text |
Language: | English |
Published: |
The Royal Society
2012
|
Subjects: | |
Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259947 http://www.ncbi.nlm.nih.gov/pubmed/21752811 https://doi.org/10.1098/rsbl.2011.0435 |
id |
ftpubmed:oai:pubmedcentral.nih.gov:3259947 |
---|---|
record_format |
openpolar |
spelling |
ftpubmed:oai:pubmedcentral.nih.gov:3259947 2023-05-15T14:48:13+02:00 Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels Williams, Cory T. Barnes, Brian M. Buck, C. Loren 2012-02-23 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259947 http://www.ncbi.nlm.nih.gov/pubmed/21752811 https://doi.org/10.1098/rsbl.2011.0435 en eng The Royal Society http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259947 http://www.ncbi.nlm.nih.gov/pubmed/21752811 http://dx.doi.org/10.1098/rsbl.2011.0435 This journal is © 2011 The Royal Society Animal Behaviour Text 2012 ftpubmed https://doi.org/10.1098/rsbl.2011.0435 2013-09-04T01:22:20Z In indigenous arctic reindeer and ptarmigan, circadian rhythms are not expressed during the constant light of summer or constant dark of winter, and it has been hypothesized that a seasonal absence of circadian rhythms is common to all vertebrate residents of polar regions. Here, we show that, while free-living arctic ground squirrels do not express circadian rhythms during the heterothermic and pre-emergent euthermic intervals of hibernation, they display entrained daily rhythms of body temperature (Tb) throughout their active season, which includes six weeks of constant sun. In winter, ground squirrels are arrhythmic and regulate core body temperatures to within ±0.2°C for up to 18 days during steady-state torpor. In spring, after the use of torpor ends, male but not female ground squirrels, resume euthermic levels of Tb in their dark burrows but remain arrhythmic for up to 27 days. However, once activity on the surface begins, both sexes exhibit robust 24 h cycles of body temperature. We suggest that persistence of nycthemeral rhythms through the polar summer enables ground squirrels to minimize thermoregulatory costs. However, the environmental cues (zeitgebers) used to entrain rhythms during the constant light of the arctic summer in these semi-fossorial rodents are unknown. Text Arctic midnight sun PubMed Central (PMC) Arctic Burrows ENVELOPE(163.650,163.650,-74.300,-74.300) Biology Letters 8 1 31 34 |
institution |
Open Polar |
collection |
PubMed Central (PMC) |
op_collection_id |
ftpubmed |
language |
English |
topic |
Animal Behaviour |
spellingShingle |
Animal Behaviour Williams, Cory T. Barnes, Brian M. Buck, C. Loren Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels |
topic_facet |
Animal Behaviour |
description |
In indigenous arctic reindeer and ptarmigan, circadian rhythms are not expressed during the constant light of summer or constant dark of winter, and it has been hypothesized that a seasonal absence of circadian rhythms is common to all vertebrate residents of polar regions. Here, we show that, while free-living arctic ground squirrels do not express circadian rhythms during the heterothermic and pre-emergent euthermic intervals of hibernation, they display entrained daily rhythms of body temperature (Tb) throughout their active season, which includes six weeks of constant sun. In winter, ground squirrels are arrhythmic and regulate core body temperatures to within ±0.2°C for up to 18 days during steady-state torpor. In spring, after the use of torpor ends, male but not female ground squirrels, resume euthermic levels of Tb in their dark burrows but remain arrhythmic for up to 27 days. However, once activity on the surface begins, both sexes exhibit robust 24 h cycles of body temperature. We suggest that persistence of nycthemeral rhythms through the polar summer enables ground squirrels to minimize thermoregulatory costs. However, the environmental cues (zeitgebers) used to entrain rhythms during the constant light of the arctic summer in these semi-fossorial rodents are unknown. |
format |
Text |
author |
Williams, Cory T. Barnes, Brian M. Buck, C. Loren |
author_facet |
Williams, Cory T. Barnes, Brian M. Buck, C. Loren |
author_sort |
Williams, Cory T. |
title |
Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels |
title_short |
Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels |
title_full |
Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels |
title_fullStr |
Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels |
title_full_unstemmed |
Daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels |
title_sort |
daily body temperature rhythms persist under the midnight sun but are absent during hibernation in free-living arctic ground squirrels |
publisher |
The Royal Society |
publishDate |
2012 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259947 http://www.ncbi.nlm.nih.gov/pubmed/21752811 https://doi.org/10.1098/rsbl.2011.0435 |
long_lat |
ENVELOPE(163.650,163.650,-74.300,-74.300) |
geographic |
Arctic Burrows |
geographic_facet |
Arctic Burrows |
genre |
Arctic midnight sun |
genre_facet |
Arctic midnight sun |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3259947 http://www.ncbi.nlm.nih.gov/pubmed/21752811 http://dx.doi.org/10.1098/rsbl.2011.0435 |
op_rights |
This journal is © 2011 The Royal Society |
op_doi |
https://doi.org/10.1098/rsbl.2011.0435 |
container_title |
Biology Letters |
container_volume |
8 |
container_issue |
1 |
container_start_page |
31 |
op_container_end_page |
34 |
_version_ |
1766319308792659968 |