Khamnigan (Khamnigan: ᠬᠠᠮᠨᠢᠭᠠᠨ) is a Mongolic language spoken by the Hamnigan people east of Lake Baikal.
Mongol is the dominant language; the two dialects of Evenki are only used by part of the population, and only within the home.
Use of the language has declined in Russia, with few speakers left, but both Khamnigan Mongol and Evenki bilingualism remain vigorous in China.
Khamnigan Mongol, on the other hand, is the most conservative Mongolic language, little different from Middle Mongolian, though the system of vowel harmony has been disrupted.
[1] Khamnigan in Mongolia has strongly assimilated to Khalkha Mongolian, and even though some Buryat-like and idiosyncratic features are to be found (e.g. the very particular mood system lacking in Khamnigan in China), it overall resembles a dialect of Khalkha, and it has lost its particular Tungusic lexicon.