Neighbour–stranger discrimination in the little owl, Athene noctua

Based on theoretical considerations, neighbour–stranger discrimination in territorial contexts is predicted and has been reported in many passerine birds. It has seldom been investigated in territorial nonpasserine species. We experimentally investigated neighbour–stranger discrimination in a year-round territorial nocturnal raptor, the little owl. We used playback of hoots to investigate whether territory owners discriminated neighbours from strangers when playback occurred at the usual location for the neighbour or at an unusual location. Male little owls responded significantly less to their neighbour's hoots played back from the usual location. However, responses to playback of a neighbour from an unusual location were similar to responses to playback of a stranger's hoots from either location. We conclude that little owls can discriminate between the hoots of neighbours and strangers. This study provides the first experimental evidence in owls for this level of neighbour–stranger discrimination, which is comparable to results found for passerines.