Sex and individual differences in cooperative nest construction of sociable weavers Philetairus socius

摘要

Complex animal societies often rely on communal resources from which all individuals in the group derive benefits. Selection should favor individuals that diminish their contribution towards these communal resources, and to increase their consumptionof the resource, thus compromising the stability of these "public goods". To begin to understand how public goods are maintained, it is useful to describe the cooperative behaviors that maintain the public good. One such public good is the communal nest in sociable weavers (Philetairus socius), which is constructed and maintained cooperatively by individual weavers in a colony. A captive colony of sociable weavers was observed for six weeks, and individuals' level of cooperative nest construction was recorded. Individuals in the colony lived in one of six possible nests and each individual focused their nest construction behavior on their respective nest of residence. Sociable weaver males cooperated at a higher level than females, with measures ofcooperation being consistent over time. These results provide the first description of cooperative nest construction in an entire colony and suggest potential mechanisms that may maintain cooperation.