Zur Brutbiologie Der Trottellumme (Uria Aalge Aalge Pont.)

The behavioural relations of the Guillemot (Uria. aalge, Pont.) to its incubating site, eggs and chicks, the significance of these relations for organising the reproductive activities within the community, and the "jumping-off" of the chicks from the incubation site down to the seashore, are described. The significance of various factors was derived from observation of the natural reproductive behaviour and conclusions were then tested by experiments with individuals marked by colour-patches.