Free-running circadian activity rhythms in free-living beaver (Castor canadensis)

Social synchronization of circadian locomotor activity rhythm in the fruit fly Drosophila melanogaster

“…Other organisms such as mice and beavers show an effect of social interactions on the circadian period (Halberg et al, 1954;Bovet and Oertli, 1974;Crowley and Bovet, 1980). Our study showed that social interactions among flies with different periods did not cause a measurable change in circadian period when made to interact one-on-one, except when per S and per L flies were paired together (Fig.1A).…”

“…In a separate study, it was shown that mice with variable circadian periods displayed synchronized behaviour as long as they were maintained together in a group (Crowley and Bovet, 1980). Similarly, members of a family of free-living beavers (Castor canadensis) displayed a synchronized period of ~27h when confined as groups to caves in winters, only to return to a 24h entrained rhythm in summers (Bovet and Oertli, 1974), suggesting that social cues maintain phase synchrony between interacting individuals. By contrast, there are also a few reports of a lack of social synchronization of circadian rhythms.…”

On the Chronobiology of Cohabitation

“…In the field, temporal synchronization among animals has been inferred from studies of Canadian beavers (Castor canadensis) living together as a family unit, as they exhibit a single coherent free-running rhythm in daily noise while they overwinter in constant darkness (DD) under thick ice (Bovet and Oertli 1974;Potvin and Bovet 1975). The period (τ) of the free-running rhythm does not correspond to any environmental factor, suggesting that social interactions alone are responsible for the synchronous group activity.…”

Social forces can impact the circadian clocks of cohabiting hamsters

“…In the wild, animals inhabit complex ecosystems involving interactions with both conspecifics and heterospecifics, and the ability to adjust one's daily activity in response to these interactions could be beneficial. For example, family groups and communities might coordinate their efforts to achieve common goals [34,35]. Conversely, when the social context involves competition, territoriality, dominance hierarchies or predator avoidance, one would predict segregation rather than synchronization of activity [21,[36][37][38][39][40][41][42].…”