B. Frisch et N. Koeniger, SOCIAL SYNCHRONIZATION OF THE ACTIVITY RHYTHMS OF HONEYBEES WITHIN A COLONY, Behavioral ecology and sociobiology, 35(2), 1994, pp. 91-98
Colonies and isolated bees of the Cape honeybee, Apis mellifera capens
is Esch., were observed for evidence of circadian rhythmicity under co
nstant conditions. It was found that colonies develop free-running act
ivity rhythms in self-selected light-dark cycles, which are slightly s
horter than 24 h. The periods of the activity rhythms of individual is
olated bees were longer than 24 h in self-selected light-dark and cons
tant light, while they were shorter than 24 h in constant darkness. A
greater variability in period was found in the isolated bees than in t
he colonies. When the rhythms of colonies and individual bees from the
se colonies were measured simultaneously, the activities of the isolat
ed bees drifted with respect to that of the colonies, their period bei
ng either longer or shorter than that of their own colony. After 12 da
ys of isolation of individual bees from their colony, all coincidence
between the phases of the two rhythms was lost. We conclude that the p
eriods of common activity and common rest of the bees within a colony
result from a mutual (social) synchronization of the rhythms of the in
dividual bees.