Seasonal metabolic acclimatization in a northern population of free-ranging snowshoe hares, Lepus Americanus

Michael John Sheriff, Louise Kuchel, Stan Boutin, Murray M. Humphries

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Seasonal acclimatization in high-latitude endotherms may involve increases or reductions in body size and metabolic rate to, respectively, augment thermoregulatory capacity or reduce energy requirements. We investigated seasonal acclimatization in a northern population of wild snowshoe hares (Lepus americanus) that is exposed to low food availability and extremely cold temperatures in winter. Snowshoe hares were livetrapped and transported to a nearby mobile laboratory. Hares were placed in a metabolic chamber and oxygen consumption was measured for 55 min at each of the following temperatures: 10°C, 0°C, - 10°C, - 15°C, and -20°C. Hair length and density were measured on a sample of collected hares. Snowshoe hares maintained similar body mass and body temperature between the seasons, but average resting metabolic rate and thermal conductance were, respectively, 20% and 32% lower in winter than in autumn. The lower critical temperature was - 10°C to - 15°C in winter and 0°C to - 10°C in autumn. Guard hairs were 36% longer and 148% denser in winter than autumn, whereas downy hairs were the same length but 128% denser in winter than autumn. Collectively, these results suggest that resource constraints associated with a herbivorous diet in regions and seasons of poor forage quality favors an energetically conservative approach to winter acclimatization.

Original languageEnglish (US)
Pages (from-to)761-767
Number of pages7
JournalJournal of Mammalogy
Volume90
Issue number3
DOIs
StatePublished - Jun 1 2009

Fingerprint

Lepus americanus
Hares
Acclimatization
acclimation
winter
autumn
hair
Hair
Population
hairs
hares
Basal Metabolism
temperature
Temperature
resting metabolic rate
thermal conductivity
body temperature
Body Size
forage quality
Body Temperature

All Science Journal Classification (ASJC) codes

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

Cite this

Sheriff, Michael John ; Kuchel, Louise ; Boutin, Stan ; Humphries, Murray M. / Seasonal metabolic acclimatization in a northern population of free-ranging snowshoe hares, Lepus Americanus. In: Journal of Mammalogy. 2009 ; Vol. 90, No. 3. pp. 761-767.
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Seasonal metabolic acclimatization in a northern population of free-ranging snowshoe hares, Lepus Americanus. / Sheriff, Michael John; Kuchel, Louise; Boutin, Stan; Humphries, Murray M.

In: Journal of Mammalogy, Vol. 90, No. 3, 01.06.2009, p. 761-767.

Research output: Contribution to journalArticle

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