Aggressive defence of food by precocial chicks varies with its concentration in space

Abstract

In juvenile and adult animals, including mammals, birds, fishes and a crustacean, competition for food becomes increasingly aggressive as its spatial concentration increases. This ecological relationship has not been investigated in infant animals, although it is thought that broods of precocial chicks of some avian species compete aggressively for food or status in a brood hierarchy. When pairs of common quail broodmates were offered the same amount of ground corn in four spatial concentrations between ages 15 and 59 days, aggression increased progressively with concentration, culminating in an overall 16-fold increase when corn was in a single clump. These results suggest that aggressive defence may increase with spatial concentration of food in precocial chicks generally, and raise the possibility that a similar pattern could occur in some altricial chicks during the transition to independence and in infants of other animal species.