As with most projects of this nature, this book began innocently. At the 1989 Animal Behavior Society meetings at Northern Kentucky University, only a handful of papers were presented on cooperative breeding and alloparental care in mammals. Two of these contributions were by the editors of this volume. At the time, much of the excitement generated by new research on cooperative breeding, either empirical or theoretical, was coming primarily from ornithologists. Woolfenden and Fitzpatrick's monograph on the Florida scrub jay and Brown's review of helping behavior in birds had been published in the previous five years. Two additional volumes, Stacey and Koenig's edited volume on long-term field studies of cooperative breeding in birds and Koenig and Mumme's monograph on the acorn woodpecker, were to be published in the immediate future. Yet it was surprising, at least to us, that, with the exception of a couple of reviews in scientific periodicals, no systematic survey or compilation of issues on cooperative breeding in mammals existed at the time.

A simple conversation was held between the editors at the 1989 meetings as we walked across a campus quad at Northern Kentucky University. The conversation, the gist of which was “someone ought to organize something”, led to a proposal to the Animal Behavior Society to conduct a symposium on the topic.