Aggregation of Eurasian Scops Owls Otus scops Breeding in Magpie Pica pica Nests

Abstract

The Eurasian Scops Owl, a small nocturnal raptor living in continental and southern Europe, is often solitary and territorial but sometimes forms local groups, of which little is known. In this study, I examined a group of territorial Scops Owls in a habitat with limited nest site availability in Southern Italy in July of 2016 and 2017. Male Scops Owls were identified through spectrographic analysis of their vocalizations, and their location was recorded. Male Scops Owls clustered around a human-inhabited area with significant noise and light pollution and avoided the undisturbed forest, which apparently was only used for foraging. The location of territories was relatively consistent in two subsequent years. Scops Owls tended to sing where conspecifics occurred, not necessarily near their own nests. Sometimes neighbouring males occupied the same area and sang simultaneously, even when close to each other. The results are in contrast with the concept of an all-purpose, exclusive territory described for this species as the norm, and suggest that the social and spatial organization of this population is more flexible than previously thought. Scops Owls bred exclusively in abandoned Eurasian Magpie Pica pica nests, which is unusual for this typically cavity-nesting species and was presumably caused by the lack of alternative sites. The distribution of Magpie nests might thus be the main driver of nest spacing and territorial behaviour of Scops Owls in this presumably nesting site limited population. However, the underlying cause of aggregation is unknown.