Opaev A. S. RussiaMoscowA. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, 33 Leninsky Prospect, Moscow 119071aleksei.opaev@gmail.com Author's articles BREEDING BIOLOGY AND SOCIAL ORGANIZATION OF EASTERN SIBERIAN STONECHAT - SAXICOLA (TORQUATUS) STEJNEGERI (PARROT, 1908) (MUSCICAPIDAE, AVES)