What are the characteristics of the red-crowned crane's living habits
The red-crowned crane is a species of crane, a large wading bird with a body length of 120-160 cm. Its neck and legs are relatively long, its body is mostly white, the top of its head is bright red, the throat and neck are black, the ear area to the nape is white, and the legs are black. When standing, the neck, the flight feathers of the tail, and the legs are black, the top of the head is red, and the rest is entirely white; when flying, only the secondary and tertiary flight feathers as well as the neck and legs are black, and the rest is all white, making the features extremely obvious and very easy to identify. Young birds have brownish heads and necks, with white body plumage tinged with chestnut. They often move in pairs, family groups, or small groups. During migration seasons and winter, several or dozens of family groups often gather into larger flocks. Sometimes the flock numbers as many as 40-50 birds, or even more than 100. However, when active they still disperse within a certain area into small groups or family groups. At night they mostly roost on shallows surrounded by water or beside reed ponds, feeding mainly on fish, shrimp, aquatic insects, mollusks, tadpoles, sandworms, clams, mud snails, and the stems, leaves, tubers, bulbs, and fruits of aquatic plants. They are distributed in Northeast China, eastern Mongolia, the eastern bank of the Ussuri River in Russia, Korea, South Korea, and Hokkaido in Japan.
The physical characteristics of the red-crowned crane
The red-crowned crane has a body length of about 160 cm, a wingspan of 240 cm, and a weight of about 10 kg. Its whole body is almost pure white, the top of the head is bare without feathers and vermilion red, the forehead and lores have slight black feathers, the ear feathers behind the eyes to the nape are white, and the cheeks, throat, and neck are black; the secondary flight feathers and tertiary flight feathers are black, and the tertiary flight feathers are long and curved, forming an arch shape and covering the tail, so when standing the tail appears black, but it is actually the tertiary flight feathers, while the tail, primary flight feathers, and the entire body plumage are all white, which is extremely obvious in flight. The bill is relatively long and pale greenish-gray, and the neck and legs are also very long. The long, curved flight feathers in the middle of the two wings are black, and when standing all the flight feathers cover the tail, often leading people to mistakenly think that it has black tail feathers. Males and females are similar.
The iris is brown, the bill is grayish-green with a yellow tip. The bare part of the tibia, as well as the tarsus and toes, are grayish-black, and the claws are gray.
The chicks are covered with yellow-brown down, with lighter color on the back, darker on the abdomen, milky white on the shoulders, and flesh-red bill and legs. After 3-4 months the body plumage gradually becomes pure white, while the bare part on the top of the head does not turn red until after 10 months.
The red-crowned crane's bones are hard on the outside and hollow inside, with a strength 7 times that of human bones, and during migration it often forms a clever wedge shape, allowing the individuals behind to successively use the airflow produced by the wing beats of the individuals in front, thereby achieving fast, effort-saving, and sustained flight, with a speed of up to about 40 km per hour, a flight altitude that can exceed 5400 m, and the ability to call while flying.
The habits of the red-crowned crane
They often move in pairs, family groups, or small groups. During migration seasons and winter, several or dozens of family groups often gather into larger flocks. Sometimes the flock numbers as many as 40-50 birds, or even more than 100. However, when active they still disperse within a certain area into small groups or family groups. At night they mostly roost on shallows surrounded by water or beside reed ponds, still dispersing by family group, and when it is especially cold they stay very close together. Feeding sites and night roosts are generally relatively fixed. Usually after dawn, each family group flies in succession to the feeding site to feed, still keeping a certain distance from one another. At noon they mostly gather at the edge of the shallows to rest, calling continuously. In the evening they fly back one after another to the night roost to spend the night or remain at the feeding site overnight. When resting, they often stand on one leg, with the head turned back and tucked among the back feathers. Whether feeding or resting, there is often 1 adult bird that is especially alert, constantly raising its head and looking around, and when it detects danger it gives a "ko-lo-lo-" call, with the head and neck stretched upward and facing the sky when calling. When danger approaches, they take off into flight. When flying, the head and feet are stretched straight forward and backward, the two wings beat slowly, and they form a "one" or "V" shape. Adult red-crowned cranes molt twice a year, changing into summer plumage in spring and winter plumage in autumn, which is a complete molt and causes them to temporarily lose the ability to fly.
The migration of the red-crowned crane
The red-crowned crane inhabits open plains, marshes, lakes, grasslands, coastal mudflats, reeds, swamps, and riverside marsh zones, and sometimes also appears in farmland and cultivated fields, especially during migration seasons and winter.
In spring they leave the wintering grounds for the breeding grounds in late February to early March, passing through Beidaihe, China, from mid-March to late March. They arrive at the breeding grounds in the Northeast from early April to mid-April. In autumn they begin to leave the breeding grounds and migrate south in late September to early October, passing through Beidaihe from mid-October to mid-November, with large numbers in early November. The leading birds arrive at the Yancheng wintering grounds in Jiangsu from October 28 to October 29, and large numbers arrive in late November. They often migrate in small flocks, with the largest flock reaching 40-50 birds. When migrating they fly in a "V"-shaped formation.