Date of this Version
Erforschung biologischer Ressourcen der Mongolei (2010) 11: 213-219.
Upland buzzards occur across Mongolia excluding lush taiga forest and breeds from the Mongolian Altai mountains to the western foothills of the Great Khyangan Mountains. Our field work was conducted during the breeding season of the species in Mongolia from 2001 to 2007. Nest materials of the studied nests contained natural (twigs of elm tree, shrubs, tail and mane of horse, hair of cows, fur of sheep, goats and camels) and artificial or man-made (cotton, plastic bags, wires, cables, and others) materials. Contents of the nesting materials of the species were differed by location, region and breeding pair’s behavior. A total of 24 different nest sites were selected by breeding pairs during the study periods. Most nests were placed on the ground (22.7%), 19.7% on artificial nest platforms (three-legged poles, single poles, car tire on poles, pylons), 16.8% on rocky outcrops, 8.8% on rocky columns or cliffs, 5.26% on type ‘A’ wooden poles of high power electric lines and 26.74% others. Average clutch was comparatively high for breeding pairs that nested on rock columns 3.9, abandoned buildings 3.7, ground 3.6, cliffs 3.3, type “A” wooden poles of the high power electric lines 3.3, sandy precipice 3 and others less than three. Average number of nestlings on the ruins of buildings was 3, rock columns 2.8, ground, telegraph poles and concrete poles of the high power electric lines 2.5, wooden poles of the high power electric lines and pylons 2.4, well building and livestock shelter 2, cliffs 1.6 and sandy precipices 1.5. There was a significant difference between the number of nestlings on natural and artificial substrates, including artificial nest platforms. We documented a breeding pair that was incubating three of its own eggs and a Saker falcon egg on a cliff of a mountain outcrop. We also observed twice the number of second clutches on natural substrates, which we consider to be dependent on food abundance and accessibility.