Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology
Dissertation (Ph.D.) University of Alaska Fairbanks, 1998 I monitored seasonal changes in body condition and dates of immergence into and emergence from hibernation in a natural population of arctic ground squirrels (Sphermophilus parryii kennicottii) living on the North Slope of Alaska. Age and sex...
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1998
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ftunivalaska:oai:scholarworks.alaska.edu:11122/9467 2023-05-15T14:31:30+02:00 Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology Buck, Charles Loren 1998 http://hdl.handle.net/11122/9467 unknown http://hdl.handle.net/11122/9467 Department of Biology and Wildlife Zoology Ecology Animal Physiology Dissertation phd 1998 ftunivalaska 2023-02-23T21:37:16Z Dissertation (Ph.D.) University of Alaska Fairbanks, 1998 I monitored seasonal changes in body condition and dates of immergence into and emergence from hibernation in a natural population of arctic ground squirrels (Sphermophilus parryii kennicottii) living on the North Slope of Alaska. Age and sex differences in changes of body condition and hibernation chronology are attributable to sex differences in energetic costs associated with preparation for reproduction and differences in reproductive status within males. While winters are long and environmental conditions faced by arctic ground squirrels in northern Alaska are extreme, the timing of hibernation did not differ appreciably from patterns observed in Sciurid populations living in temperate latitudes. To determine the environmental conditions faced by S. parryii during hibernation and to investigate the effect of overwinter temperature on change in body condition of the individual, I instrumented 18 burrow sites with temperature-sensitive data loggers to record soil temperature at hibernacula depth. Burrow sites did not differ significantly in soil temperature over years, but significant thermal differences were observed among burrows. Burrows with more shrubby vegetation accumulated deeper snow and had higher overwinter temperatures than did windswept sites. Females hibernated at warmer sites than did males and adults hibernated at warmer sites than juveniles. Repeated measures of overwinter changes in body condition were not significantly correlated with winter soil temperatures for any age or sex class. To determine the energetic cost associated with hibernation under arctic conditions, I measured metabolic rate, respiratory quotient, and body temperature of arctic ground squirrels in steady-state torpor. At ambient temperatures below 0$\sp\circ$C, body temperature remained constant and metabolic rate increased proportional to the gradient between body and ambient temperatures. With increased metabolic rate associated with decreased ambient ... Doctoral or Postdoctoral Thesis Arctic ground squirrel Arctic north slope Alaska University of Alaska: ScholarWorks@UA Arctic Burrows ENVELOPE(163.650,163.650,-74.300,-74.300) Fairbanks |
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University of Alaska: ScholarWorks@UA |
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Zoology Ecology Animal Physiology |
spellingShingle |
Zoology Ecology Animal Physiology Buck, Charles Loren Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology |
topic_facet |
Zoology Ecology Animal Physiology |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 1998 I monitored seasonal changes in body condition and dates of immergence into and emergence from hibernation in a natural population of arctic ground squirrels (Sphermophilus parryii kennicottii) living on the North Slope of Alaska. Age and sex differences in changes of body condition and hibernation chronology are attributable to sex differences in energetic costs associated with preparation for reproduction and differences in reproductive status within males. While winters are long and environmental conditions faced by arctic ground squirrels in northern Alaska are extreme, the timing of hibernation did not differ appreciably from patterns observed in Sciurid populations living in temperate latitudes. To determine the environmental conditions faced by S. parryii during hibernation and to investigate the effect of overwinter temperature on change in body condition of the individual, I instrumented 18 burrow sites with temperature-sensitive data loggers to record soil temperature at hibernacula depth. Burrow sites did not differ significantly in soil temperature over years, but significant thermal differences were observed among burrows. Burrows with more shrubby vegetation accumulated deeper snow and had higher overwinter temperatures than did windswept sites. Females hibernated at warmer sites than did males and adults hibernated at warmer sites than juveniles. Repeated measures of overwinter changes in body condition were not significantly correlated with winter soil temperatures for any age or sex class. To determine the energetic cost associated with hibernation under arctic conditions, I measured metabolic rate, respiratory quotient, and body temperature of arctic ground squirrels in steady-state torpor. At ambient temperatures below 0$\sp\circ$C, body temperature remained constant and metabolic rate increased proportional to the gradient between body and ambient temperatures. With increased metabolic rate associated with decreased ambient ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Buck, Charles Loren |
author_facet |
Buck, Charles Loren |
author_sort |
Buck, Charles Loren |
title |
Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology |
title_short |
Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology |
title_full |
Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology |
title_fullStr |
Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology |
title_full_unstemmed |
Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology |
title_sort |
physiological ecology of the arctic ground squirrel: energy metabolism, torpor, and behavioral endocrinology |
publishDate |
1998 |
url |
http://hdl.handle.net/11122/9467 |
long_lat |
ENVELOPE(163.650,163.650,-74.300,-74.300) |
geographic |
Arctic Burrows Fairbanks |
geographic_facet |
Arctic Burrows Fairbanks |
genre |
Arctic ground squirrel Arctic north slope Alaska |
genre_facet |
Arctic ground squirrel Arctic north slope Alaska |
op_relation |
http://hdl.handle.net/11122/9467 Department of Biology and Wildlife |
_version_ |
1766305114126024704 |