Seasonal dynamics in social behaviour and spacing patterns of the Little Owl Athene noctua

Abstract

Most owl species exhibit territorial behaviour in order to have sufficient resources to maintain their fitness and biological success. The Little Owl (Athene noctua) has been considered a territorial species, although some authors have pointed to movements and social interactions outside a particular territory. We hypothesise that the spatial behaviour and social organisation of Little Owl follows a complex pattern, which varies throughout the year. We radio-tracked nine Little Owls in an area of 10 km(2) over nine months, paying particular attention to home range variation, social interaction and vocal behaviour. Home range size and overlap varied markedly throughout the year, with maximums in winter, and minimum size and overlap during the breeding season. Little Owls showed exclusive home ranges during the breeding season, whereas home range overlap was frequent in winter. Owls which had lost clutches increased their home ranges and shared the same foraging areas with other owls. Vocal activity was low all year round, except in the months immediately prior to courtship. Increase of vocal behaviour was therefore also associated with a reduction in home range.