AUTUMN MIGRATION OF GREY CRANE GRUS GRUS IN THE TERRITORY OF SOUTHERN PREDBAIKALYE
On the basis of long-term researches (1963-2007) materials on autumn migration of a grey crane in the territory of Southern Predbaikalye are resulted. Supervision was conducted by the standard methods used for studying of cranes [3, 4, 27]. Special studying of migrations was carried out with use of time and constant observation posts, according to Yu.E. Keskpaik''s recommendations [3, 4]. Their sizes were determined with conditions of concrete sites of works, in view of an opportunity of full monitoring during all time of supervision. Were carried out both evening and morning accounts, and supervision during all light time of day, mainly, on sites of mass flight of birds of this species. Results of long-term researches of autumn migration of a grey crane in Southern Predbaikalye confirm existence here well expressed flight of this species. Birds fly wide front with low intensity of flight during second half of August and all September. However on separate sites of this region well defined channels offlight which are used by many species shorebirds and a waterfowl are formed: Baikal-Angara-Yenisei, Torei-Baikal-Angara and Torei-Kirenga-Tunguska flying ways. From them the first and the third differ enough high intensity of migrations of a grey crane. For Torei-Baikal-Angara a flying way well expressed migration of this species is characteristic weak enough but nevertheless. The most significant migration way distinguished by high number of a grey crane (about 15,0 thousand birds) is marked on Baikal-Angara-Yenisei direction. All other migratory directions practically completely coincide with known ways of flight of other species of birds and for a grey crane are minor. Here its separate flights though during separate seasons, completely unexpectedly, on them mass enough fligh t of birds of this species is observed are marked only. As a rule, it is connected to serious enough natural anomalies: strong incessant rains, early approach of colds or on the contrary long warm weather, it is sharp be replaced passage of extensive fronts of adverse weather conditions. It is quite obvious, that formation of sites of mass flight in such conditions is determined with meteorological conditions in the extensive territories, promoting concentration of birds on separate sites, optimum for continuation of migration.