Surface area: 90,476 ha
Elevation: 583-609 m

Protection status: Unprotected.

Site description: Buir is freshwater lake located on the border of the Mongolia in Khalkh soum territory, Dornod province. The northwestern small part of the lake belongs to China’s territory. Khalk River enters to the lake from its northeast, forming large wet meadow around confluence area. Shores at this part are flat and there grow dense reeds and rushes at the end of Khalkh River. Orshuun River flows out from the lake. The lake freezes over from November to April. There stretches about 500-1000 meters wide sand dunes along the southern and eastern shores of the lake, while there is stipe steppe away from here. There are several small lakes along the edge of the sand dunes. There also numerous small lakes in the east of the lake. Land degradation of the main area with reeds, where waterbirds live, poaching, overfishing, decrease of water level and poorly managed tourism are major threats to the site. The Buir Lake is included in Ramsar site.

Importance for birds: Globally threatened bird species such as Oriental Stork (Ciconia boyciana), Swan Goose (Anser cygnoides), Baikal Teal (Anas Formosa), Pallas’s Fish-eagle (Haliaeetus leucoryphus), Lesser Kestrel (Falco naumanni), Siberian Crane (Grus leucogeranus), White-naped Crane (G.vipio), Great Bustard (Otis tarda) and Relict Gull (Larus relictus) occur at the site. Bird species restricted to the Eurasian steppe and desert biomes occur here. Great Crested Grebe (Podiceps cristatus), Great Cormorant (Phalacrocorax carbo), Grey Heron (Ardea cinerea), Swan Goose (Anser cygnoides), Ruddy Shelduck (Tadorna ferruginea), Common Shelduck (T. tadorna) and Northern Lapwing (Vanellus vanellus) gather in flocks, exceeding 1% of their flyway populations.

Special flora and fauna: Mongolian Gazelle (Procapra gutturosa), Eurasian Otter (Lutra lutra) and Taimen (Hucho taimen), listed in International Red Data Book oocur at the site. Thousand of heads of Mongolian Gazelle graze here. A very rare Acorus colamus grow at the site.