The parent-chick feeding relationship of the Puffin, Fratercula arctica.

Abstract

1. The feeding relationship between the puffin parent and chick was studied to examine whether the parent or its chick determines the duration of feeding and the quantity of food the chick receives.
2. The quantity of food brought to wild chicks decreases prior to their fledging. Artificially reared chicks did not reject additional food until the day before fledging implying that chicks do not influence the decrease in the parents' feeding rate. Nevertheless, when large quantities of fish were available chicks did reject progressively more food before fledging.
3. Chicks that received additional food did not fledge either earlier or heavier than control chicks.
4. A series of chick-exchange experiments were conducted to examine the way in which adults determine the number of feeds the chicks receive. When chicks of the same age were exchanged foster parents continued to feed the chick at the normal rate. When chicks of different ages were exchanged the parents tended to feed according to their previous schedule rather than the age of the foster chick. Thus, adults appear to determine the quantity of food chicks receive. All chicks fledged at a similar age to control chicks and were not deserted by their foster parents, implying that chicks may determine the duration of the feeding schedule.