Seasonality in Biological Rhythms in Scandinavian brown Bears
Biological rhythms, such as rhythms in activity and body temperature, are usually highly synchronized and entrained by environmental conditions, such as photoperiod. However, how the expression of these rhythms changes during hibernation, when the perception of environmental cues is limited, has not...
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fthsinnlandet:oai:brage.inn.no:11250/3009969 2024-03-03T08:49:17+00:00 Seasonality in Biological Rhythms in Scandinavian brown Bears Thiel, Alexandra Giroud, Sylvain Hertel, Anne Gabriela Friebe, Andrea Devineau, Olivier Fuchs, Boris Blanc, Stephane Støen, Ole-Gunnar Laske, Timothy G. Arnemo, Jon Martin Evans, Alina 2022 application/pdf https://hdl.handle.net/11250/3009969 https://doi.org/10.3389/fphys.2022.785706 eng eng Frontiers in Materials. 2022, 13 . urn:issn:2296-8016 https://hdl.handle.net/11250/3009969 https://doi.org/10.3389/fphys.2022.785706 cristin:2023529 Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no 0 13 Frontiers in Materials Brown bear (Ursus arctos) body temperature circadian rhythm heart rate hibernation lomb-scargle periodogram multiday rhythms activity VDP::Matematikk og Naturvitenskap: 400 Peer reviewed Journal article 2022 fthsinnlandet https://doi.org/10.3389/fphys.2022.785706 2024-02-02T12:42:10Z Biological rhythms, such as rhythms in activity and body temperature, are usually highly synchronized and entrained by environmental conditions, such as photoperiod. However, how the expression of these rhythms changes during hibernation, when the perception of environmental cues is limited, has not yet been fully understood for all hibernators, especially in the wild. The brown bear (Ursus arctos) in Scandinavia lives in a highly seasonal environment and adapts to harsh winter conditions by exhibiting hibernation, characterized by reduced metabolism and activity. In this study, we aimed to explore the expression of biological rhythms in activity, body temperature and heart rate of free-ranging brown bears over the annual cycle, including active, hibernation and the transition states around den entry and exit. We found that rhythms in physiology and activity are mostly synchronized and entrained by the light-dark cycle during the bears’ active state with predominantly diel and ultradian rhythms for body temperature, activity, and heart rate. However, during hibernation, rhythms in body temperature and heart rate were considerably slowed down to infradian rhythms, influenced by the amount of snow in the denning area, whereas rhythms in activity remained diel. Rhythms in the transition states when bears prepared for entering or coming out of hibernation state displayed a combination of infradian and diel rhythms, indicating the preparation of the body for the change in environmental conditions. These results reveal that brown bears adjust their biological rhythms to the seasonal environment they inhabit. Rhythms in physiology and activity show simultaneity during the active state but are partly disconnected from each other during hibernation, when bears are most sheltered from the environment. publishedVersion Article in Journal/Newspaper Ursus arctos Høgskolen i Innlandet: Brage INN Frontiers in Physiology 13 |
institution |
Open Polar |
collection |
Høgskolen i Innlandet: Brage INN |
op_collection_id |
fthsinnlandet |
language |
English |
topic |
Brown bear (Ursus arctos) body temperature circadian rhythm heart rate hibernation lomb-scargle periodogram multiday rhythms activity VDP::Matematikk og Naturvitenskap: 400 |
spellingShingle |
Brown bear (Ursus arctos) body temperature circadian rhythm heart rate hibernation lomb-scargle periodogram multiday rhythms activity VDP::Matematikk og Naturvitenskap: 400 Thiel, Alexandra Giroud, Sylvain Hertel, Anne Gabriela Friebe, Andrea Devineau, Olivier Fuchs, Boris Blanc, Stephane Støen, Ole-Gunnar Laske, Timothy G. Arnemo, Jon Martin Evans, Alina Seasonality in Biological Rhythms in Scandinavian brown Bears |
topic_facet |
Brown bear (Ursus arctos) body temperature circadian rhythm heart rate hibernation lomb-scargle periodogram multiday rhythms activity VDP::Matematikk og Naturvitenskap: 400 |
description |
Biological rhythms, such as rhythms in activity and body temperature, are usually highly synchronized and entrained by environmental conditions, such as photoperiod. However, how the expression of these rhythms changes during hibernation, when the perception of environmental cues is limited, has not yet been fully understood for all hibernators, especially in the wild. The brown bear (Ursus arctos) in Scandinavia lives in a highly seasonal environment and adapts to harsh winter conditions by exhibiting hibernation, characterized by reduced metabolism and activity. In this study, we aimed to explore the expression of biological rhythms in activity, body temperature and heart rate of free-ranging brown bears over the annual cycle, including active, hibernation and the transition states around den entry and exit. We found that rhythms in physiology and activity are mostly synchronized and entrained by the light-dark cycle during the bears’ active state with predominantly diel and ultradian rhythms for body temperature, activity, and heart rate. However, during hibernation, rhythms in body temperature and heart rate were considerably slowed down to infradian rhythms, influenced by the amount of snow in the denning area, whereas rhythms in activity remained diel. Rhythms in the transition states when bears prepared for entering or coming out of hibernation state displayed a combination of infradian and diel rhythms, indicating the preparation of the body for the change in environmental conditions. These results reveal that brown bears adjust their biological rhythms to the seasonal environment they inhabit. Rhythms in physiology and activity show simultaneity during the active state but are partly disconnected from each other during hibernation, when bears are most sheltered from the environment. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Thiel, Alexandra Giroud, Sylvain Hertel, Anne Gabriela Friebe, Andrea Devineau, Olivier Fuchs, Boris Blanc, Stephane Støen, Ole-Gunnar Laske, Timothy G. Arnemo, Jon Martin Evans, Alina |
author_facet |
Thiel, Alexandra Giroud, Sylvain Hertel, Anne Gabriela Friebe, Andrea Devineau, Olivier Fuchs, Boris Blanc, Stephane Støen, Ole-Gunnar Laske, Timothy G. Arnemo, Jon Martin Evans, Alina |
author_sort |
Thiel, Alexandra |
title |
Seasonality in Biological Rhythms in Scandinavian brown Bears |
title_short |
Seasonality in Biological Rhythms in Scandinavian brown Bears |
title_full |
Seasonality in Biological Rhythms in Scandinavian brown Bears |
title_fullStr |
Seasonality in Biological Rhythms in Scandinavian brown Bears |
title_full_unstemmed |
Seasonality in Biological Rhythms in Scandinavian brown Bears |
title_sort |
seasonality in biological rhythms in scandinavian brown bears |
publishDate |
2022 |
url |
https://hdl.handle.net/11250/3009969 https://doi.org/10.3389/fphys.2022.785706 |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_source |
0 13 Frontiers in Materials |
op_relation |
Frontiers in Materials. 2022, 13 . urn:issn:2296-8016 https://hdl.handle.net/11250/3009969 https://doi.org/10.3389/fphys.2022.785706 cristin:2023529 |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no |
op_doi |
https://doi.org/10.3389/fphys.2022.785706 |
container_title |
Frontiers in Physiology |
container_volume |
13 |
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1792506484615020544 |