Begging behaviour of nestlings and food delivery by parents: the importance of breeding strategy

Studies of begging behaviour and food provisioning have produced contradictory results. Here, I present a new idea that may explain these apparent contradictions based on the fact that in species with brood reduction (brood reducers) some chicks starve, but in species that adjust clutch size (clutch adjusters) all chicks typically survive to fledge. This suggests that parents adopting these different strategies may follow different provisioning rules. In clutch adjusters, parents tend to distribute food equitably among their chicks, preferentially feeding young that are in poorer condition, but in brood reducers parents selectively feed larger chicks independently of begging intensity. Received in revised form: 27 March 2001 Electronic Publication