Infant handling in wild Cebus capucinus: testing bonds between females?
1Department of Anthropology, University of California, Los Angeles
Animal Behaviour
|March 8, 1999
Summary
Infant handling in white-faced capuchins primarily tests social bonds between adult females, not learning to mother or reciprocity. This behavior is linked to grooming and coalition formation, suggesting a role in social relationships.
Area of Science:
- Primate behavior
- Social cognition
- Ethology
Background:
- The evolutionary purpose of infant handling (IH) by female primates is not well understood for many species.
- Existing hypotheses include learning-to-mother, reciprocity, harassment, alliance formation, and bond-testing.
Purpose of the Study:
- To investigate the functions of infant handling in wild white-faced capuchins.
- To test the hypothesis that IH serves to test social bonds between adult females.
- To evaluate alternative hypotheses for IH behavior.
Main Methods:
- Focal subjects were mothers of 10 infants (0-90 days old).
- Observed behaviors comprising IH (inspecting, nuzzling, sniffing, vocalization) and compared them to maternal behavior.
- Analyzed IH rates in relation to female dominance rank, grooming, coalition formation, and allonursing.
Main Results:
- IH behaviors differed from typical maternal care.
- IH rates were unrelated to dominance ranks.
- Females handled infants of those with whom they groomed and formed aggressive coalitions more frequently.
- No evidence for reciprocal IH or correlation with allonursing.
Conclusions:
- The learning-to-mother, reciprocity, and harassment hypotheses were unsupported.
- Some support was found for the nonadaptive hypothesis.
- Findings suggest IH in this species may function to test and maintain social bonds, particularly related to alliance formation.
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