crane

The whooping crane Grus americana of North America is exceedingly rare in the wild. It breeds in Canada and migrates to the Texas coast in winter. Like all cranes, whooping cranes migrate in flocks, flying in V-formation or in lines, with necks forward and legs trailing.

The red-crowned crane Grus japonensis. Cranes inhabit plains and marsh regions, feeding on grain, plants, and small animals. This individual was photographed in Kenya.

Japanese cranes on a frozen lake in Hokkaido, Japan.

In zoology, a large, wading bird of the family Gruidae, order Gruiformes, with long legs and neck, short powerful wings, a naked or tufted head, and unwebbed feet. The hind toe is greatly elevated, and has a sharp claw. Cranes are marsh- and plains-dwelling birds, feeding on plants as well as insects and small animals. They fly well and are usually migratory. Their courtship includes frenzied, leaping dances. They are found in all parts of the world except South America.

The common crane Grus grus is still numerous in many parts of Europe, and winters in Africa and India. It stands over 1 m/3ft high. The plumage of the adult bird is grey, varied with black and white, with a red patch of bare skin on the head and neck. All cranes have suffered through hunting and loss of wetlands; the population of the North American whooping crane G. americana fell to 21 wild birds in 1944. Through careful conservation, numbers have now risen to about 400.

The sandhill crane of North America, G. canadensis, reaches a height of 1 m/3 ft and has greyish plumage, with a red patch on the head. It winters in Mexico and breeds in the far north. The demoiselle crane Anthropoides virgo breeds in eastern Europe and northern Asia, and winters in Africa and southern Asia. The Siberian crane G. leucogeranus is one of the most endangered migratory birds, with only two wild populations consisting of about 3,000 birds in total.

crane

In engineering, a machine for raising, lowering, or placing in position heavy loads. The three main types are the jib crane, the overhead travelling crane, and the tower crane. Most cranes have the machinery mounted on a revolving turntable. This may be mounted on trucks or be self-propelled, often being fitted with caterpillar tracks.

The main features of a jib crane are a power winch, a rope or cable, and a movable arm or jib. The cable, which carries a pulley block, hangs from the end of the jib and is wound up and down by the winch. The overhead travelling crane, chiefly used in workshops, consists of a fixed horizontal arm, along which runs a trolley carrying the pulley block. Tower cranes, seen on large building sites, have a long horizontal arm able to revolve on top of a tall tower. The arm carries the trolley.

Cranes can also be mounted on barges or large semisubmersibles for marine construction work.