UMass Chan Medical School Faculty Publications


Social synchronization of circadian rhythmicity in female mice depends on the number of cohabiting animals

UMMS Affiliation

Department of Neurology

Publication Date


Document Type



Neuroscience and Neurobiology | Physiology


Communal animals often engage in group activities that require temporal synchrony among its members, including synchrony on the circadian timescale. The principles and conditions that foster such collective synchronization are not understood, but existing literature hints that the number of interacting individuals may be a critical factor. We tested this by recording individual circadian body temperature rhythms of female house mice housed singly, in twos (pairs), or in groups of five (quintets) in constant darkness; determining the daily phases of the circadian peak for each animal; and then calculating the cycle-to-cycle phase relationship between cohabiting animals over time. Significant temporal coherence was observed in quintets: the proportion of quintets (4/7), but not pairs (2/8), that became synchronized was greater than could be achieved by the complete simulated reassortment of all individuals. We speculate that the social coupling of individual circadian clocks of group members may be adaptive under certain conditions, and we propose that optimal group sizes in nature may depend not only on species-specific energetics, spatial behaviour and natural history but also on the mathematics of synchronizing assemblies of weakly coupled animal oscillators.


body temperature, circadian rhythms, social interactions, wavelet analysis

DOI of Published Version



Biol Lett. 2015 Jun;11(6):20150204. doi: 10.1098/rsbl.2015.0204. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

Biology letters

PubMed ID