Japanese crane, Manchurian crane
The Red-crowned crane (Grus japonensis) is a large graceful East Asian crane. It is among the rarest cranes in the world. In some parts of its range, this bird is known as a symbol of luck, longevity, and fidelity.
Adult Red-crowned cranes are named for a patch of red bare skin on the crown, which becomes brighter during the mating season. Overall, they are snow white in color with black on the wing secondaries, which can appear almost like a black tail when the birds are standing, but the real tail feathers are actually white. Males are black on the cheeks, throat, and neck, while females are pearly gray in these spots. The bill is olive green to a greenish horn, the legs are slate to grayish black, and the iris is dark brown. Juveniles are a combination of white, partly tawny, cinnamon brown, and rusty or grayish. The neck collar is grayish to coffee brown, the secondaries are dull black and brown, and the crown and forehead are covered with gray and tawny feathers. The primaries are white, tipped with black, as are the upper primary coverts. The legs and bill are similar to those of adults but lighter in color.
Red-crowned cranes live in eastern Russia in the Amur River basin and in China and Japan and other parts of southeastern Asia. Currently, there are two main populations of Red-crowned cranes; one is non-migrating and lives in northern Japan on the island of Hokkaido. The other population breeds in Russia, north-eastern China, and Mongolia, migrating to eastern China, and to North and South Korea, spending the winter there. Red-crowned cranes are very much an aquatic species. They will feed in water that is much deeper than other crane species will, feeding in pastures in summer and in winter moving to coastal saltmarsh, cultivated fields, rice paddies, rivers, and freshwater marshes.
Red-crowed cranes are social birds and live in flocks. When they preen, they rub a special oil onto their feathers that they secrete from a gland by the top of their tail, to keep their feathers conditioned. They are active during the day and usually seek food in deep water marshes, feeding by pecking as they walk. Their long toes mean that they can walk in soil that is soft and muddy, and they use their long bill to probe the water for prey. Red-crowned cranes communicate with each other during their courtship dance. They also have a call for contact, which tells other birds where they are. A chick's contact call sounds much louder and is more strident than an adult’s; this helps to get attention when they are in distress. They are also able to communicate aggression by means of inflating the red caps on their heads.
Red-crowned cranes are omnivores; their diet consists of fish, insects, aquatic invertebrates, amphibians, rodents, reeds, heath berries grasses, corn, and other plants. In winter they also eat grain and waste from agricultural fields.
Red-crowned cranes are monogamous and form long pair bonds which they strengthen by their beautiful displays of dancing. The male and female also have a unison call that they produce before they begin their courtship dance. The breeding season is in spring and the birds return every year to the same nesting sites. They build their nests either on wet ground or shallow water over waters no more than 20 to 50 cm (7.9 to 19.7 in) deep. Sometimes, nests are built on the frozen surface of the water. This nest is made from grass and weeds and is built by both partners. The female usually lays 2 eggs and incubation is for 29 to 34 days and is shared by both parents. The female incubates at night, and both parents take turns at the nest during the day. The chicks are precocial (fully developed) and leave the nest a few days after they hatch. They follow their parents around when foraging. The young typically fledge in 70 days but remain together with their parents for around 9 months. Reproductive maturity is usually attained when young birds are between 2 and 3 years old.
The main threats to this species include habitat loss and fragmentation, but to a lesser extent also human disturbances near their nesting grounds, poisoning, and poaching. The most pressing threat is habitat destruction, with a general lack of remaining pristine wetland habitats for the species to nest. In Japan, little proper nesting habitat remains and the local breeding population is close to the saturation point.
According to IUCN Red List, the total population size of the Red-crowned crane in discrete wintering areas is 3,822 individuals; 1,900 in Japan in 2020, 1,669 individuals in Korea, and 353 in China. The estimated number of mature individuals is estimated to be around 2,300 individuals. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List but its numbers today are decreasing.
