Ural Owl in north of Byelarus: nesting density and breeding biology. - A.K. Tishechkin, V.V. Ivanovsky. - Berkut. 7 (1-2). 1998. P. 55-63.
Research was carried out in 1985-1996. Density of territorial males or pairs on 3 study plots in the Berezinsky Nature Reserve, Gorodok and Rosson districts by the area 140-760 km2, determined on the basis of the long-term point accounts with application of vocalization records, has made 4,5-9,5 on 100 km2. Some indirect data about the possible high degree of residence and attachment to the territory are obtained. Total 24 nesting cases were watched in 18 found nests that placed in nests of big birds (77 %), mainly birds of prey, and also open hemihollows and hollows. Though the revealed distribution of nesting places most likely differs from real, it is supposed, that the significant part of pairs uses open nests. The beginning of egg laying occurs on the end of March - beginning of April (long-term median - 1.04). The average long-term clutch size is 2,73. About 90 % of nesting attempts were successful, on an active nest is on the average 1,71 fledglings. The appreciable interannual distinctions in terms and breeding success are marked. The comparison of biology Byelorussian ural owls with the data on Fennoscandia has shown similarity in reproductive features of the species in both regions. The possible differences connected to distinctions in availability and use of nesting places and food supply are discussed. [Russian].
Key words: Ural Owl, Strix uralensis, Northern Byelarus, breeding
biology, population density, breeding success, clutch size, nesting place.
Address: Dr. A. Tishechkin, 402 Life Sciences Building, Louisiana State University, Baton Rouge, LA 70803 - 1710, U.S.A.