Temperatures of hibernacula and changes in body composition of arctic ground squirrels over winter

C. Loren Buck, Brian M. Barnes

Research output: Contribution to journalArticlepeer-review

71 Scopus citations

Abstract

Soil temperatures near hibernacula of free-living arctic ground squirrels (Spermophilus parryii) were recorded over 3 winters (October-April 1993-1996) at Toolik Lake, Alaska. Means and minima of soil temperature at 20 burrows averaged -8.9 and -18.8°C, respectively. Soil temperatures were <-3°C for, on average, >5 months, which represented the duration of winter that hibernating arctic ground squirrels were actively thermogenic. Individual burrows did not differ significantly in mean soil temperature over 3 years, but significant differences in mean and minimum soil temperatures were observed among burrows. Sites of burrows with shrubby vegetation accumulated more snow and had significantly higher soil temperatures over winter than windswept sites in non-shrubby vegetation. Female ground squirrels hibernated in burrows that had significantly higher mean and minimum soil temperatures than burrows of males, and adults hibernated in burrows with significantly higher soil temperatures than burrows of juveniles. Although ground squirrels occupying colder burrows were predicted to lose more body mass during hibernation than those in warmer burrows, changes in body, fat, and lean masses over winter were not correlated with soil temperature for any sex or age. Relationships between change in body composition of hibernating arctic ground squirrels and temperatures of their hibernacula may be confounded by use of food caches, differing thermal conductance of nests, or differences in individual's energetics of hibernating not related to the gradient between body and soil temperatures.

Original languageEnglish (US)
Pages (from-to)1264-1276
Number of pages13
JournalJournal of Mammalogy
Volume80
Issue number4
DOIs
StatePublished - Nov 1999
Externally publishedYes

Keywords

  • Alaska
  • Arctic
  • Body composition
  • Burrow
  • Ground squirrel
  • Hibernaculum
  • Hibernation
  • Spermophilus parryii
  • Temperature

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology
  • Animal Science and Zoology
  • Genetics
  • Nature and Landscape Conservation

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