A re-evaluation of the social organisation of the Callitrichidae, with reference to the ecological differences...

Field studies of callitrichid species have reported a surprising degree of variation in the composition of social groups, some of which has been interpreted as evidence of 'cooperative polyandry' in recent reviews. The majority of the evidence is, however, derived from studies of only one of the four callitrichid genera, Saguinus. While most features of the morphology and behaviour of all callitrichid species are broadly similar, studies of marmosets (Callithrix spp. and Cebuella pygmaea) indicate that important ecological differences exist between genera. These differences appear, in turn, to be reflected in marked contrasts in both social organisation and mating systems. A re-evaluation of the social organisation of the callitrichids, based on differences in their ecological adaptations, is presented.