Metabolism and thermal response in winter-acclimatized pygmy rabbits (Brachylagus idahoensis)

Publication Type:

Journal Article

Authors:

Katzner, Todd E.; Parker, Katherine L.; Harlow, Henry H.

Source:

Journal of Mammalogy, American Society of Mammalogists, Volume 78, Issue 4, p.1053-1062 (1997)

Call Number:

A97KAT02IDUS

URL:

http://www.jstor.org/stable/1383048

Keywords:

Brachylagus idahoensis, pygmy rabbit

Abstract:

Resting metabolic rate of pygmy rabbits (0.89 ml 02 [the 2 is subscripted] g-1 [-1 is superscripted] h-1 [-1 is superscripted] was high compared to other eutherian mammals, but not unusual among lagomorphs. The estimated size of the zone of thermoneutrality was ca. 8–9 ˚C, with the lower critical temperature occurring between 15 and 20 ˚C, depending on body mass. Minimum thermal conductance was lower and mean body temperature was higher than predicted for similarly sized mammals. Body temperature fluctuated >1 ˚C within a 24-h period, but showed no circadian patterns. Pygmy rabbits are thermally stressed during harsh winters in Wyoming, but low thermal conductance, a high-energy source of food, and favorable microenvironments enhance survival.