Hibernation and body weight in dormice: a new type of endogenous cycle.

Under conditions unfavorable to hibernateion (22 degrees C), the body-weight cycles of dormice are only a few weeks long, but under conditions in which dormice hibernate (5 degrees C), the cycles can last many months; the more the animals hibernate, the longer are the cycles. Such cycles contrast with the relative independence from torpor of the period of circannual cycles in other hibernating rodents and with the temperature compensation of circannual and circadian cycles in general.