The Crane on bogs of Tver region. - V.I. Nikolayev. - Berkut. 4 (1-2). 1995. P. 38-39.
Data were collected in 1980-1994. Cranes were found on 50 bogs in all districts of the region. On 12 peatbogs nesting is possible. The number this species on bogs is estimated in 500-600 pairs. With cranes nesting in other biotopes it makes about 900 pairs. The biotopic distribution on the different types of bogs is described. The population density of the Crane is 0,04-0,1 pairs/km2 on the high bogs and 0,1-0,3 pairs/km2 on the transitory and back bogs. The groups to 80 unbreeding birds are met on bogs and fish ponds in summer. It is known several places of the premigration accumulations of cranes. In August they stay on fields with winter crops and later move to spring-sown and potatoes fields. There is the tendency to the decrease of numbers in the region. The main negative factors are melioration of bogs and working of the peat. [Russian].
Key words: Crane, Tver region, bog, distribution, population density, number.