Cooperation and Reciprocity in Avian Social Systems

Here I describe a variety of mutually beneficial interactions between birds that typically are not genetically related. As viewed here, avian cooperation and reciprocity can take several forms. In addition to monogamy and reciprocal exploitation I recognize two major categories of reciprocity, "obligate" and "opportunistic." Obligate reciprocity occurs in populations in which an individual must have one or more allies to have much chance of...