Patterns of social preference across different social contexts in golden lion tamarins (Leontopithecus rosalia).

We investigated the role of mutual and circumstantial factors in maintaining exclusive social relationships in a New World primate. Four breeding pairs of golden lion tamarins (Leontopithecus rosalia rosalia) were allowed to interact with their mate or an unfamiliar, opposite-sex adult in each of 4 different social contexts: in view of the mate, out of the mate's view, with only the mate present, and with only the unfamiliar animal present. Males and females were in proximity to, approached, and sniffed their mates significantly more often than they did unfamiliar tamarins. These behaviors suggest a preference for the familiar mate. However, when mates were absent, tamarins demonstrated significantly higher levels of approach and sniffs toward unfamiliar animals. These patterns of behavior indicate that circumstantial factors, such as social context, may regulate social interactions between paired tamarins and unfamiliar, opposite-sex conspecifics.