Snow crane, Siberian white crane, Siberian crane, Siberian white crane, Snow crane
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.
The Siberian crane is the world's third most endangered species of crane. Amongst cranes, its serrated bill makes it unique, and enables it to easily feed on underground roots and slippery prey items. It has white plumage, identifiable by its red mask and white cap, the mask reaching from behind its eye to its bill. In a juvenile, the mask is feathered and its body is buff or cinnamon-colored.
Siberian cranes are spread throughout three populations: western, eastern, and central. These distinct populations range from Yakutia in arctic Russia to western Siberia. The population in the east breeds in northeast Siberia and migrates to China to the Yangtze River for winter. The central population of cranes breeds in western Siberia then migrates to Rajasthan in India for winter, mainly at the Keoladeo National Park. The population in the west spends winter in Iran on the Caspian sea's southern coast and breeds in Russia's northwest. These cranes feed and nest primarily in marshes, bogs and other wetlands where there are wide reaches of shallow fresh water with good visibility. They live mainly in lowland tundra, taiga biogeographic, and taiga/tundra transition regions.
Siberian cranes are not very social. During breeding and winter seasons individuals are territorial. Family flocks number about 12 to 15 cranes. They are aquatic birds, and use the wetlands for feeding, roosting, nesting and other behavioral displays. During the day they roost in shallow water, preen, and nest, and during the breeding season, attend to their young. At night Siberian cranes stand on one leg and tuck their head under their shoulder. Dancing behavior, such as leaping and bowing, is not directly connected to the reproductive cycle in these cranes, but it does reflect a bird's excitement. Cranes will dance with or without a partner, at any time, their head and neck being brought forward from a vertical position to where the head reaches down and back between their legs.
Siberian cranes are omnivorous and in summer have a more varied diet, which includes roots, rhizomes, sprouts of sedges, seeds and other plant items. They also eat insects, rodents, fish, and small animals. When migrating and in winter, they feed mainly on plant material, and aquatic animals if available.
Siberian cranes are monogamous and make strong pair-bonds. Courtship and pair bonding behavior includes dancing and unison calling, which is an extended and complex series of coordinated calls, usually initiated by the male. Breeding takes place in spring and summer. Siberian cranes usually nest in marshes, bogs, and other wetlands. Two eggs are laid and both parents incubate them, for about 29 days. The two eggs hatch but typically only one chick survives to be raised. Both male and female feed and protect their young, males spending more time feeding than females. The chick fledges in about 70 to 75 days and is sexually mature within 3 years.
Siberian cranes are threatened with habitat loss and degradation in their wintering areas, breeding grounds and stopover sites. Other major threats include agriculture expansion, drainage of wetlands, oil extraction and human development. Hunting in Pakistan and Afghanistan during migration affects them as well.
According to the IUCN Red List, the total population size of the Siberian crane is 3,500-4,000 individuals. Siberian cranes’ numbers are decreasing today and they are classified as critically endangered (CR) on the list of threatened species.
Siberian cranes have an impact on the wetland areas of their environment when they feed on plant shoots and roots.
