Social spacing in domestic fowl under seminatural conditions: the effect of behavioural activity and activity transitions

Males and females of two strains of domestic fowl, a commercial medium hybrid laying strain and a more primitive bantam type of mixed genetic background, were released into a large (110 m X 80 m) outdoor enclosure. The birds formed two single-strain flocks. Observations were made of flock areas, nearest neighbour distances and distances to the outlying individual of each flock. There were significant differences between the strains in all measurements, the bantam flock forming the more cohesive flock with smaller nearest-neighbour distances and shorter distances to the most outlying individual. There was also a significant effect of behavioural activity on spacing behaviour and these trends were the same for both strains. Birds were furthest apart when they were walking, closer when they were ground pecking, even closer when they were standing and closest when they were preening. To investigate this relationship between spacing behaviour and behavioural activity in more detail, another group, this time of the medium hybrid strain only, were released into the same enclosure the following year. In this second experiment, the movements of birds towards and away from each other were found to be associated with behavioural activity transitions. The direction of these movements was significantly correlated to the direction of the activity transition.