Habitat Selection of Eurasian Scops OwlOtus scopson the Northern Border of Its Range, in Europe

Abstract

Habitat selection of the Eurasian Scops Owl Otus scops was studied in Ljubljansko barje (central Slovenia, 180 km2) where abiotic conditions, especially climate, could be considered suboptimal for this xerothermophilic species. Data on the number and distribution of calling males were gathered in May and June 2004–06 using the playback method. A total of 137 calling males were counted (29 in 2004, 66 in 2005, 42 in 2006). To avoid pseudo-replication, 72 non-overlapping sites were selected for habitat analysis. Habitat within 250-m radius plots surrounding owl sites was compared with 136 unoccupied and non-overlapping sites. Within plots, 14 habitat variables were measured. Discriminating variables between occupied and non-occupied sites were identified with stepwise logistic regression. Scops Owl occupation was positively associated with the number of tree lines, and slightly negative with the surface area of woodland and settlements. Scops Owls preferred sites with a higher than average proportion of traditional orchards, tree lines, scrub, unimproved meadows, and tree plantations. Tree plantations were only used by owls during 2005, when the number of calling males was highest. All males were unpaired, perhaps indicating inexperienced or late-arriving males outcompeted to marginal habitat. Conservation actions needed to maintain this population of Scops Owl at the northern border of its breeding range include: (1) preserve and rejuvenate traditional orchards and isolated trees in farmyards, (2) encourage renovation of old houses and their farmyards and discourage high density housing, (3) protect and restore tree lines and copses, (4) enlarge the proportion of unimproved meadows, and (5) limit the increase of cropland and the use of biocides.