Solving the Collective action problem during intergroup encounters: the case of black and gold howler monkeys (Alouatta caraya)

KOWALEWSKI, M MARTIN; GARBER, PAUL A

Howler Monkeys: Examining the Biology, Adaptive Radiation, and Behavioral Ecology of the Most Widely Distributed Genus of Neotropical Primate

Springer Press

Año: 2012; p. 1 - 46

Growing evidence from field studies highlights the importance of social affiliation, social bonds, and cooperation in understanding primate behavior and social structure. In several platyrrhine species, intersexual and intrasexual cooperation and tolerance in the form of dyadic and group-level social interactions are reported to serve a critical role the ability of individuals to obtain access to mates, effectively patrol and defend home ranges and feeding sites, and increase offspring survivorship. Howlers constitute a good model for testing hypotheses concerning the costs and benefits of collective action as they usually live in cohesive social groups composed largely of unrelated or distantly related adults. We explored evidence of collective action in howlers focusing on Argentina black and gold howlers (Alouatta caraya). We investigated the participation of individually recognized resident adult males in howling, vigilance and fighting bouts during intergroup encounters, an event during which extragroup males attempt to enter established groups and mate with resident females. During these encounters, some or all resident adult males responded by howling and approaching the intruder. Based on data on individual male participationduring intergroup encounters, we argue that the collective action of several males benefits both actors and other group members by reducing opportunities for male takeovers, infanticide, and social disruption in established groups. Individuals may adjust their participation during these encounters in order to reduce the costs and enhance the benefits of collective action in maintaining reproductive access to resident females. We suggest that intergroup encounters are platforms where collective action problems may arise, arenegotiated and solved through joint actions by central males and noncentral males. We also present limited data on male collective action in other howler species.