Comparative food niche analysis of Strix Owls in Belarus

Three Strix species breed sympatrically in Belarus. The Tawny Owl (Strix aluco) is one of two commonest owl species in the country, and is distributed throughout the whole territory. Its' range overlaps widely with two other species, the Ural Owl (S. uralensis) which is common in the forests of the northern part and the Great Gray Owl (S. nebulosa) which occurs in a rather limited area in the southern region. The diet of all three species was studied from 1986-1996 by the analysis of pellets collected mainly near nests. All owls preyed mainly on voles and shrews, but niche differences between them are apparent. The Great Gray Owl appeared to be a vole specialist, while the Tawny Owl had the most diverse diet, often feeding on mice, anurans, insects, and birds. The food niche of the Ural Owl was between these extremes.