AJP - Regulatory, Integrative and Comparative Physiology, Vol 246, Issue 6 955-R958, Copyright © 1984 by American Physiological Society
Circannual rhythms of body weight in pallid bats
L. J. Beasley, K. M. Pelz and I. Zucker
Body weights of pallid bats collected in the field were substantially
greater during October and December than between April and September. When
maintained in the laboratory under constant conditions of photoperiod and
temperature, bats manifested circannual rhythms in body weight. These
endogenous cycles were observed in adult and juvenile individuals of both
sexes and in bats housed in long or short photoperiods (14 or 10 h of
light/day). The period of the cycle averaged 10 mo. Photoperiod influenced
the timing and magnitude of the body weight cycle; bats kept in short
photoperiods achieved peak body weights earlier than animals housed in long
day lengths. We propose that day length is one of the proximate factors for
synchronization of circannual cycles of pallid bats.
