The effects of hibernation stress on the heart rate and metabolic rate of Citellus lateralis.

1. Heart rates and oxygen consumption of hibernating Citellus (= Spermophilus) lateralis were evaluated at various body temperatures. 2. Hibernation-stress animals had significantly higher heart rates as well as elevated rates of oxygen consumption at all body temperatures than did their less-stressed counterparts. 3. The higher metabolic rates of stressed animals were not due simply to their elevated heart rates. 4. It appears that unstressed animals have an energetic advantage over hibernation-stress animals.