Abstract # 2283 Event # 195:

Scheduled for Saturday, June 23, 2007 10:50 AM-11:05 AM: Session 19 (North Main Hall C/D) Symposium


J. French
University of Nebraska at Omaha, Callitrichid Research Center, Omaha, NE 68182, USA
     Cooperative breeding is a widespread phenomenon in animals, occurring throughout both vertebrate and invertebrate subphyla. The defining features of cooperative breeding are delayed dispersal of offspring, reproductive suppression of subordinates, and care of offspring by individuals other than the breeding individuals. Three conceptual advances in behavioral ecology have provided insight into the evolutionary origin of the cluster of traits associated with cooperative breeding. Ecological constraints on dispersal determine whether individuals other than breeders are likely to be in contact with dependent young, and hence have the opportunity to deliver alloparental care. Reproductive skew models help us appreciate conditions under which subordinates might or might not attempt independent reproduction. Finally, Hamiltonian kin selection and reciprocal altruism are important tools for explaining why individuals provide care for others’ offspring. The idea of a “eusociality continuum” suggests that the traits associated with cooperative breeding can vary among species and even within species. Recent work has revealed that cooperative breeding can be highly conditional, and variation in social and ecological variables can determine whether individuals in a given species express one or more of the traits associated with cooperative breeding. The flexibility of these behavioral characteristics surely accounts for the growing number of primates that express cooperative breeding, as witnessed by the empirical papers in this symposium. Supported by NSF IBN 00-09130 and NIH HD 42882.