Expression And Mechanisms Of Hibernation In The Artic: The Alaska Marmot And Arctic Ground Squirrel
Dissertation (Ph.D.) University of Alaska Fairbanks, 2012 The Arctic is home to animals that have taken adaptations to overwintering to extremes. In this dissertation, I have investigated one of these adaptations, hibernation, in two species from the Arctic, the Alaska marmot (Marmota broweri) and t...
Main Author: | |
---|---|
Other Authors: | , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | unknown |
Published: |
2012
|
Subjects: | |
Online Access: | http://hdl.handle.net/11122/9128 |
id |
ftunivalaska:oai:scholarworks.alaska.edu:11122/9128 |
---|---|
record_format |
openpolar |
spelling |
ftunivalaska:oai:scholarworks.alaska.edu:11122/9128 2023-05-15T14:31:28+02:00 Expression And Mechanisms Of Hibernation In The Artic: The Alaska Marmot And Arctic Ground Squirrel Lee, Trixie Nicole O'Brien, Diane Buck, Loren Taylor, Barbara Barnes, Brian 2012 http://hdl.handle.net/11122/9128 unknown http://hdl.handle.net/11122/9128 Department of Biology and Wildlife Conservation biology Animal Physiology Wildlife conservation Dissertation phd 2012 ftunivalaska 2023-02-23T21:37:12Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2012 The Arctic is home to animals that have taken adaptations to overwintering to extremes. In this dissertation, I have investigated one of these adaptations, hibernation, in two species from the Arctic, the Alaska marmot (Marmota broweri) and the arctic ground squirrel (Urocitellus parryii ). The expression of hibernation under natural conditions in these species was compared by collecting body temperature records of free-living individuals. The Alaska marmot, a highly social species, demonstrated extreme synchrony in body temperature patterns among a family group, indicating a strong reliance on social thermoregulation. In contrast, the arctic ground squirrel was confirmed to be a solitary hibernator that reduces body temperature below freezing during torpor. Both species must produce heat when soil temperatures are significantly below freezing for most of the winter. At these subfreezing ambient temperatures, the arctic ground squirrel has shown an increasing reliance on nonlipid fuel during torpor, driving a loss of lean mass during hibernation of ~20%. I calibrated deuterium dilution to repeatedly estimate body composition in this species, which dramatically changes adiposity through its annual cycle, and used this technique to quantify lean mass loss throughout hibernation in a study of tissue metabolism. I also developed and applied the natural abundance of nitrogen and carbon stable isotopes as tools for monitoring differential tissue metabolism and differentiating mixed metabolic fuel use in the arctic ground squirrel. These data clarified the mechanism of change in nitrogen stable isotopes and indicated that hibernating ground squirrels rebuild organ tissues while breaking down muscle tissue to meet energetic demands. Furthermore, I corroborated a shift in metabolic fuel use toward nonlipid sources during torpor at low ambient temperatures by using the carbon isotope ratio in exhaled breath in combination with respiratory quotient. This ... Doctoral or Postdoctoral Thesis Arctic ground squirrel Arctic Urocitellus parryii Alaska University of Alaska: ScholarWorks@UA Arctic Fairbanks |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
unknown |
topic |
Conservation biology Animal Physiology Wildlife conservation |
spellingShingle |
Conservation biology Animal Physiology Wildlife conservation Lee, Trixie Nicole Expression And Mechanisms Of Hibernation In The Artic: The Alaska Marmot And Arctic Ground Squirrel |
topic_facet |
Conservation biology Animal Physiology Wildlife conservation |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2012 The Arctic is home to animals that have taken adaptations to overwintering to extremes. In this dissertation, I have investigated one of these adaptations, hibernation, in two species from the Arctic, the Alaska marmot (Marmota broweri) and the arctic ground squirrel (Urocitellus parryii ). The expression of hibernation under natural conditions in these species was compared by collecting body temperature records of free-living individuals. The Alaska marmot, a highly social species, demonstrated extreme synchrony in body temperature patterns among a family group, indicating a strong reliance on social thermoregulation. In contrast, the arctic ground squirrel was confirmed to be a solitary hibernator that reduces body temperature below freezing during torpor. Both species must produce heat when soil temperatures are significantly below freezing for most of the winter. At these subfreezing ambient temperatures, the arctic ground squirrel has shown an increasing reliance on nonlipid fuel during torpor, driving a loss of lean mass during hibernation of ~20%. I calibrated deuterium dilution to repeatedly estimate body composition in this species, which dramatically changes adiposity through its annual cycle, and used this technique to quantify lean mass loss throughout hibernation in a study of tissue metabolism. I also developed and applied the natural abundance of nitrogen and carbon stable isotopes as tools for monitoring differential tissue metabolism and differentiating mixed metabolic fuel use in the arctic ground squirrel. These data clarified the mechanism of change in nitrogen stable isotopes and indicated that hibernating ground squirrels rebuild organ tissues while breaking down muscle tissue to meet energetic demands. Furthermore, I corroborated a shift in metabolic fuel use toward nonlipid sources during torpor at low ambient temperatures by using the carbon isotope ratio in exhaled breath in combination with respiratory quotient. This ... |
author2 |
O'Brien, Diane Buck, Loren Taylor, Barbara Barnes, Brian |
format |
Doctoral or Postdoctoral Thesis |
author |
Lee, Trixie Nicole |
author_facet |
Lee, Trixie Nicole |
author_sort |
Lee, Trixie Nicole |
title |
Expression And Mechanisms Of Hibernation In The Artic: The Alaska Marmot And Arctic Ground Squirrel |
title_short |
Expression And Mechanisms Of Hibernation In The Artic: The Alaska Marmot And Arctic Ground Squirrel |
title_full |
Expression And Mechanisms Of Hibernation In The Artic: The Alaska Marmot And Arctic Ground Squirrel |
title_fullStr |
Expression And Mechanisms Of Hibernation In The Artic: The Alaska Marmot And Arctic Ground Squirrel |
title_full_unstemmed |
Expression And Mechanisms Of Hibernation In The Artic: The Alaska Marmot And Arctic Ground Squirrel |
title_sort |
expression and mechanisms of hibernation in the artic: the alaska marmot and arctic ground squirrel |
publishDate |
2012 |
url |
http://hdl.handle.net/11122/9128 |
geographic |
Arctic Fairbanks |
geographic_facet |
Arctic Fairbanks |
genre |
Arctic ground squirrel Arctic Urocitellus parryii Alaska |
genre_facet |
Arctic ground squirrel Arctic Urocitellus parryii Alaska |
op_relation |
http://hdl.handle.net/11122/9128 Department of Biology and Wildlife |
_version_ |
1766305084937863168 |