Prof. Dr. Luis Ebensperger (Departamento de Ecología, P. Universidad Católica de Chile): "The socially unstable life of a communally rearing small mammal"
in: 'Frontiers in Ecology and Evolution': "The socially unstable life of a communally rearing small mammal"
by Prof. Dr. Luis Ebensperger (Departamento de Ecología, P. Universidad Católica de Chile)
Members of social groups typically experience frequent affiliative interactions with other such members among them, which may result in the formation of specific and enduring relationships (social bonds). These bonds in turn may predispose individuals to cooperate and attain fitness benefits from sociality. However, individual membership within social groups may vary, implying social instability. Thus, the functional consequences of such instability remain little understood. Available evidence (mostly from a few social mammals) is generally consistent with that social instability results in detrimental effects. I aim to illustrate how social instability and cooperation may coexist in degus, a group-living rodent from the Neotropics. Especially, I show field-based data supporting that social instability is associated with decreased number of offspring weaned in the females. Experimental evidence supports that social instability interferes with communal rearing of the offspring. On the other hand, males from socially unstable groups produce more offspring, implying a potential sexual conflict. We suspect social instability benefits males though enhancing mating opportunities, either from the same or from different, neighboring social groups. I finally discuss how social instability may be fitness enhancing to the females.