The Siberian Crane Grus leucogeranus has a world population estimated at only 3,200 (Wetlands International, 2006), with more than 95% of these wintering around Poyang Lake in the River Yangtze Flood-plain, China. Threats to the species include hunting (perhaps especially in the tiny western and central populations), and habitat degradation, with changes to the flood regime of the Yangtze River due to the Three Gorges Dam of very great concern, and a major reason for its listing by BirdLife International as Critically Endangered. In response to the species’ very poor conservation status, a special Memorandum of Understanding has been developed for the Siberian Crane, under the auspices of the Convention on The Conservation of Migratory Species of Wild Animals (see: http://www.cms.int/species/siberian_crane/sib_bkrd.htm).
Based on counts at sites like Beidaihe in coastal Hebei, most Siberian Crane appear to migrate around the top of the Yellow Sea (rather than across it). The Siberian Crane is therefore a very irregular migrant through the Republic of Korea, with less than 10 individuals reported to date. There were only seven records between 1992 (the first) and 2004, when an adult was seen and photographed by observers as it migrated southwest through Korea. Found at Seosan on November18th and remaining until the next morning, the same adult was then relocated and photographed by Park Jong-Gil on Daeheuksan Island 250 km to the southwest! It was present only until the next morning.
After three winters with no records, an adult was found at Suncheon Bay in early December, with a juvenile found on December 16th c. 50 km to the southwest. This latter bird was accompanying a small group of White-naped Crane Grus vipio, and was present at least until 21st. It is perhaps notable that these birds arrived in Korea the same winter as the first Siberian Crane recorded in southwest Japan since 2003, and the first reported at Hangzhou Bay in Zhejiang Province (just south of Shanghai) China in 30 years (Simba Chan in lit. to Oriental Birding Listserver, November 2008). It seems likely that a small number of Siberian Cranes have been displaced southward down the Korean peninsula during their migration.
For more background information on the Critically Endangered Siberian Crane: