Red-crowned Crane

Order: Gruiformes
Family: Gruidae
Genus/Species: Grus japonensis

Description:
The Red-crowned Crane is a stately long-legged, long-necked bird whose immaculate snow-white plumage is accented by black secondary feathers, a black neck with contrasting white nape, and a red crown. They stand 1.5 m tall, average 7-10 kg in weight and have a 2.5 m wing span. Unique among the four species of "white" cranes (a group that also includes the Hooded Crane, Black-necked Crane and Whooping Crane) they have snow white primary feathers. The black secondaries form an elegant curling black bustle when the bird is standing. Juvenile birds are also predominately white with black-tipped primaries and dull grayish-brown neck and secondary feathers. Sexes are similar in appearance. They are very long-lived, reaching ages greater than 70 years in captivity.

Cranes have specialized vocal adaptations highlighted by an extremely long trachea that coils within a hollow sternum. They produce a wide variety of calls ranging from low pitched purrs to the loud unison calls involved in courtship and pair maintenance. The calls of male and female cranes differ in pitch.

Distribution and Habitat:
The white cranes are the most aquatic of the world's 15 crane species. They inhabit wide open marshes, bogs, and wet meadows where high visibility in daylight leaves them with less need to remain inconspicuous from predators. They have very sharp eyesight, spotting intruders and potential hazards from hundreds of meters away. Red-crowned Cranes roost overnight in rivers or streams to take advantage of the deeper water for predator defense. Their flashy plumage may aid them in territory maintenance.

There are two main breeding populations of Red-crowned Cranes: on the northern Japanese island of Hokkaido, and a larger mainland population that breeds in northeast China and southeastern Russia (sometimes referred to as the Manchurian Crane). The Hokkaido population breeds and winters in the same geographic area, with individuals seldom moving more than 150 km from season to season. The mainland birds divide into sub-populations as they migrate to wintering grounds on both coasts of North Korea, the Demilitarized Zone, and the Jiangsu region of central China.

Diet:
Red-crowned Cranes prefer to forage in deep water marshes where they prey on insects, aquatic invertebrates, fish, amphibians and small rodents. They also frequent dikes, rice fields, and other croplands where they feed on waste grains and other plant material. The Hokkaido and South Korean birds take advantage of public and privately maintained winter feeding stations located on refuges and local farms.

Reproduction:
Once a firm pair bond has been established, Red-crowned Cranes usually remain mated for life, although they will replace a mate that has died. The most spectacular aspect of crane courtship is the dancing ceremony. They prance stiff-legged around each other, alternately bowing and stretching, with their wings half extended. They punctuate the dance by leaping high into the air with their legs dangling loosely beneath them. When excited they pick up small sticks or pieces of grasses, toss them exuberantly into the air, and then stab at them on the way back down. They perform a duet of their ringing unison calls to further strengthen the pairing.

Cranes are spring breeders, usually nesting in April or May. Shortly before laying commences, both sexes participate in constructing a large ground nest of reeds and grasses in a marshy area, sometimes completely surrounded by water. They female lays two large light brown eggs, liberally spotted with darker shades of brown. Both parents share in the 29- to 34-day incubation. The newly hatched chicks are covered in light brown down and are able to follow their parents almost immediately.

Because incubation commences when the first egg is laid, the hatch is asynchronous, with the first chick emerging two days ahead of the second. The older chick usually monopolizes its parents attention and bullies its younger sibling. It is rare for both chicks to survive to fledging. The parents are very attentive, continually capturing prey items and offering them to the chick by holding them to the end of its bill. Though they grow rapidly, they still require more than three months to fledge. They do not reach sexual maturity until they are three to four years old.

Relationship to Humans:
Called tancho by the Japanese, the Red-crowned Crane has always had a conspicuous presence in Japanese culture. Reputed in folklore to live one thousand years, they are a symbol of longevity. Their well-deserved reputation for fidelity makes them a popular symbol in wedding ceremonies. The crane has been a common theme in Japanese art for many centuries.

Conservation:
The only crane more critically endangered than the Red-crowned Crane is the North American Whooping Crane. The Red-crowned Crane is listed on CITES appendix 1, with a total world population estimated at 1500 in the wild with another 700 in zoos around the world. The National Zoo supports the conservation of the Red-crowned Crane by participating in the Species Survival Plan.

The privilege of hunting the magnificent tancho was reserved for the Japanese nobility until 1867. The subsequent increase in hunting pressure drove the cranes from the southern Japanese islands by the end of the 19th century. Both the Hokkaido and mainland populations were devastated by World War II and the Korean War. By the severe winter of 1950 the Hokkaido birds were reduced to 25 half-starved birds huddled around a hot spring. Local farmers came to their rescue by supplying them with grain. Japan designated the tancho as its national bird in 1952.

Supplemental feeding, rigorous protection and unflagging public support have enabled them to rebound to over 600 birds by the 1990's. Some researchers believe that this number is actually higher than the natural carrying capacity of the habitat. They worry about the increased risk of disease to birds that gather in such large numbers at the artificial feeding stations. Deaths from power line collisions have been reduced by a program to make the lines more visible to the birds.

The Red-crowned Crane is protected as a National Monument in South Korea and is also legally protected in North Korea and Russia. Although several species of crane are now enjoying the peace and solitude of the Demilitarized Zone, this critical habitat is under constant threat of development or renewed hostilities. All of the breeding and wintering areas are imperiled by agricultural development, wetlands degradation, proposed dams, poaching, poisoning, intentional burning of marshes, catastrophic storms and industrial development.

References:
Austin, O. 1961. Birds of the World. Golden Press. New York.

Del Hoyo, J., Elliot, A. and J. Sargatal. eds. Handbook of Birds of the World, Vol. 3. Lynx Edicions, Barcelona.

Ellis, D. H., Gee, G. F. and C. M. Mirande. 1996. Cranes: Their Biology, Husbandry, and Conservation. Hancock House Publishing, Blaine, Washington.

Matthiessen, P. 1995. The Cranes of Hokkaido. Audubon 97(4):36-47.