Abstract

Circannual Clocks: Annual Biological Rhythms documents the Proceedings of a Satellite Symposium of the 140th Meeting of the American Association for the Advancement of Science held in San Francisco, California, February 25, 1974. The purpose of the symposium was to summarize the present state of knowledge on endogenous annual rhythms (circannual clocks), and to point out their biological significance and importance.
The presentations included studies on the following: the circannual rhythms of an arthropod, the cave crayfish, Orconectes pellucidus inermis, and a cnidarian, Campanularia flexuosa; the occurrence, manifestation, and importance of circannual rhythms in birds with different migratory habits; and the importance of circannual rhythms in hibernating mammals. Also covered are the relationships between circannual rhythms and endogenous lunar and tidal rhythms; circannual rhythm of reproduction in male European starlings; the adaptational value of internal annual clocks in birds; the expression and suppression of the circannual antler growth cycle in deer; and circannual rhythms in man.