The swan goose (Anser cygnoides) is a large goose that breeds primarily in Mongolia, Inner Mongolia and eastern Russia and winters in southern and eastern China. Introduced populations, many of which are domesticated and non-migratory, occur elsewhere in Asia. The numbers of wild swan geese have declined rapidly in the past century. Threats include habitat loss from agricultural development, dam construction, and the grazing and cutting of marsh vegetation, as well as unsustainable levels of hunting and egg collection.
This is one of the globally endangered bird species living in Daurian ecoregion. Dauria is the home to 43,000 Swan-Geese. In July 2004 the personnel of the three nature reserves conducted a bird census across vast areas of Mongolia, China, and Russia. This research revealed the presence in Dauria of 75% of the world’s wild population, estimated as 50,000-60,000 birds. It turned out that Dauria is not only the world’s most important nesting place for Swan-Geese, it is also the only place on the planet where these birds molt. About 98% of Swan-Geese in Dauria are non-breeding birds that gather in the middle of summer in huge flocks on big steppe lakes. In July the geese lose their wing feathers and for almost a month they are unable to fly. This is a very complicated period for Swan-Geese, when they need safe and food rich habitats. The research showed that many lakes of Dauria, with vast underwater meadows of pondweed (main geese food item), perfectly suit the birds in the molting period and attract immature (one- or two year-old) swan-geese from the huge area of this species nesting range.
This goose’s most important habitat in Dauria is Lake Buir-Noor, which is located in Mongolia and partially in China. In 2003 scientists counted 29,056 birds there. This lake is the most important place for the Swan-Goose molt. Up to half (!) of the world population gathers there and the area remains unprotected. Khuhnuur Lake and other water bodies in the lower reaches of the Uldz River also have great importance for the birds protected within Mongol Daguur nature reserve. Other important habitats include Torey lakes in Russia, Lake Dalainor and Wulan-Nur, and Huihe river valley in China as well as Argun River valley on the border between Russia and China.
In late-July, 2006 scientists from the U.S. Geological Survey, the Mongolian Academy of Sciences and Wildlife Science Conservation Center, in collaboration with the Korea National Science Museum, deployed three global positioning transmitters (GPS) on wild swan geese to satellite track their movements. Molting birds were captured during their flightless period in the Amur Basin headwaters in northeastern Mongolia and transmitters were attached using harnesses. To track the migration of geese see links: