Thermoregulation of Arctic Weasels
1979; University of Chicago Press; Volume: 52; Issue: 2 Linguagem: Inglês
10.1086/physzool.52.2.30152560
ISSN1937-4267
AutoresTimothy M. Casey, Kathleen Casey,
Tópico(s)Ocean Acidification Effects and Responses
ResumoThermoregulation of Arctic least weasels (Mustela rixosa) and ermines (Mustela erminea) in winter and summer pelage was studied at Point Barrow, Alaska. Mean body temperatures at Ta's ranging from −10 to 30 C were about 40 C and independent of Ta. Basal metabolism of both species in either winter or summer pelage was significantly greater than predicted values for other mammals based on body mass, but half or less the values previously reported for M. rixosa. Elevated Vo2, in thermoneutrality was associated with higher rates of ventilation than predicted, yielding extraction coefficients similar to those of other small mammals. Below thermoneutrality, increased ventilation by both elevated frequency and tidal volume generally followed increases in oxygen demand. Thermal conductance of both species in winter or summer pelage was higher than that of other mammals of similar size and showed essentially the same relation to body mass as exhibited by long-tailed weasels, a larger species from a warmer climate. Conductance did not vary seasonally in these species.
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