[Inborn orientation procedures during feeding in guillemots (Uria aalge aalge Pont.)].

Guillemots (Uria aalge) swallow fish head first when they are fed, when they pick up fish from the ground and when hunting. The responsible orientation processes in the first two situations are investigated. Experiments on over 300 hand-reared chicks, partly food-naive, showed that when they are fed, swallowing the fish head first results from a combination of orientation processes on the part of the parent and the chick. When picking up fish it results solely from characteristics of the fish. It is explained why the Taxis theory does not seem applicable. Instead of this the study is based on the theory of orientation processes.