Summary
The first specimen of Great tit from Amur River basin was collected on the Shilka River in the eastern Trans-Baikal in May, 1855 by R. Maack (1859), and breeding by Japanese tits was strictly proved in 1869 at Lake Khanka, in southwest Ussuriland (Przhewalski, 1876), but not any further north. Examination of high-quality colour photographs of the type specimen of P. m. bargaensis (Yamashina, 1939), collected on 22 April, 1935 on the eastern shore of Lake Dalainor (in the western foothills of the Great Khingan Mountains), has conclusively shown that it was a hybrid between P. major and P. minor.