The Siberian crane (Leucogeranus leucogeranus), also known as the Siberian white crane or the snow crane, is a bird of the family Gruidae, the cranes. They are distinctive among the cranes: adults are nearly all snowy white, except for their black primary feathers that are visible in flight, and with two breeding populations in the Arctic tundra of western and eastern Russia. The eastern populations migrate during winter to China, while the western population winters in Iran and (formerly) in Bharatpur, India.
Among the cranes, they make the longest distance migrations. Their populations, particularly those in the western range, have declined drastically in the 20th century due to hunting along their migration routes and habitat degradation. The world population was estimated in 2010 at about 3,200 birds, mostly belonging to the eastern population with about 95% of them wintering in the Poyang Lake basin in China, a habitat that may be altered by the Three Gorges Dam.
Siberian cranes are widely dispersed in their breeding areas and are highly territorial. They maintain feeding territories in winter but may form small and loose flocks, and gather closer at their winter roosts. They are very diurnal, feeding almost all throughout the day. When feeding on submerged vegetation, they often immerse their heads entirely underwater. When calling, the birds stretch their neck forward. The contexts of several calls have been identified and several of these vary with sex. Individual variation is very slight and most calls have a dominant frequency of about 1.4 kHz. The unison calls, duets between paired males and female however are more distinctive with marked differences across pairs. The female produces a higher pitched call which is the "loo" in the duetted "doodle-loo" call. Pairs will walk around other pairs to threaten them and drive them away from their territory. In captivity, one individual was recorded to have lived for nearly 62 years while another lived for 83 years.
These cranes feed mainly on plants although they are omnivorous. In the summer grounds they feed on a range of plants including the roots of hellebore (Veratrum misae), seeds of Empetrum nigrum as well as small rodents (lemmings and voles), earthworms and fish. They were earlier thought to be predominantly fish eating on the basis of the serrated edge to their bill, but later studies suggest that they take animal prey mainly when the vegetation is covered by snow. They also swallow pebbles and grit to aid in crushing food in their crop. In their wintering grounds in China, they have been noted to feed to a large extent on the submerged leaves of Vallisneria spiralis. Specimens wintering in India have been found to have mainly aquatic plants in their stomachs. They are however noted to pick up beetles and birds eggs in captivity.
Siberian cranes return to the Arctic tundra around the end of April and beginning of May. The nest is usually on the edge of lake in boggy ground and is usually surrounded by water. Most eggs are laid in the first week of June when the tundra is snow free. The usual clutch is two eggs, which are incubated by the female after the second egg is laid. The male stands guard nearby. The eggs hatch in about 27 to 29 days. The young birds fledge in about 80 days. Usually only a single chick survives due to aggression between young birds. The population increase per year is less than 10%, the lowest recruitment rate among cranes. Their success in breeding may further be hampered by disturbance from reindeer and sometimes dogs that accompany reindeer herders. Captive breeding was achieved by the International Crane Foundation at Baraboo after numerous failed attempts. Males often killed their mates and captive breeding was achieved by artificial insemination and the hatching of eggs by other crane species such as the Sandhill and using floodlights to simulate the longer daylengths of the Arctic summer.
Historic records from India suggest a wider winter distribution in the past including records from Gujarat, near New Delhi and even as far east as Bihar. In 1974 as many as 75 birds wintered in Bharatpur and this declined to a single pair in 1992 and the last bird was seen in 2002. In the 19th century, larger numbers of birds were noted to visit India. They were sought after by hunters and specimen collectors. An individual that escaped from a private menagerie was shot in the Outer Hebrides in 1891. The western population may even have wintered as far west as Egypt along the Nile.
Satellite telemetry was used to track the migration of a flock that wintered in Iran. They were noted to rest on the eastern end of the Volga delta. Satellite telemetry was also used to track the migration of the eastern population in the mid-1990s, leading to the discovery of new resting areas along the species' flyway in eastern Russia and China. The Siberian crane is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies and is subject of the Memorandum of Understanding concerning Conservation Measures for the Siberian Crane concluded under the Bonn Convention. 2b1af7f3a8