Mamayev A. B. RussiaSaratovSaratov branch of A. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 24 Rabochaya Str., Saratov 410028, Russiaoparinml@mail.ru Author's articles STATISTICAL ANALYSIS OF THE DISTURBANCE FACTOR INFLUENCE ON THE SPATIAL STRUCTURE FORMATION OF THE GREAT BUSTARD (OTIS TARDA L.) (OTIDIDAE, AVES) POPULATION IN THE TRANS-VOLGA REGION ABUNDANCE OF TETRAX TETRAX L. 1758 (OTIDIDAE, AVES) IN THE SARATOV REGION