Cranes
Cranes
Cranes are tall, wading birds known for their beauty, elaborate courtship dances, and voices that boom across their wetland habitat. Their family, Gruidae, is among the oldest on Earth. Today 15 crane species are found throughout the world, except in South America and Antarctica. Two species, the whooping crane (Grus americana ) and the sandhill crane (G. canadensis ) are found in North America. Cranes belong to order Gruiformes, which also includes rails, coots, trumpeters, and the limpkin.
Cranes have long legs, a long neck, and a narrow, tapered bill. Most of them have a featherless spot on the top of the head that exposes colored skin. Some have wattles, or flaps of flesh, growing from the chin. The wattled crane (Bugeranus carunculatus ) of eastern and southern Africa has very large wattles. This bird looks more like a chunky stork than a typical crane. Although cranes do look rather like storks and herons, those birds have a toe that points backward, enabling them to grasp a tree branch while perching. Cranes have a backward toe, but in all except the crowned crane (Balearica spp.) it is raised up off the ground and of no use in grasping branches. Crowned cranes are able to perch in trees like storks.
Most cranes migrate fairly long distances to their nesting sites. Their large, strong wings allow them, once airborne, to glide on air currents, taking some of the strain out of the long trip. When flying, cranes stretch their neck and legs straight out, making a long straight body-line. They can cruise at speeds of about 45 mph (72 kph).
Cranes are highly vocal birds. They make many different sounds, from a low, almost purring sound, apparently of contentment, to a loud, high-pitched call that announces to other birds one is about to take flight. Mating pairs of cranes will often point their beaks to the sky and make long, dramatic calls that have been called unison calls or bonding calls. Cranes have a long windpipe that gives volume to their calls.
Cranes eat grains, especially liking waste corn and wheat found in harvested fields. They also eat
invertebrates they catch in the water. Both in water and on land, cranes often stand on one foot, tucking the other under a wing.
Dancing and mating
Cranes are noted for their amazing dances that bond individual males and females together. These dances are elaborate and ballet-like, and are among the most intricate and beautiful in the animal kingdom. The cranes bow, leap high into the air, and twirl with their wings held out like a skirt. However, this wonderful dance is not only a courtship dance because once a pair has bonded, they are mated for life. Cranes dance at other times, too, possibly as a way of relieving frustration, which might otherwise erupt into aggression. They also appear to dance for pleasure. Very young cranes start dancing with excitement.
A pair of cranes construct a raised nest of dried grasses by water. Either parent might start incubating as soon as the first egg is laid, although they usually lay two eggs. Crowned cranes often lay three eggs. The eggs hatch after about 28-31 days of incubation. Both parents feed the chicks and take care of them long past the time that they grow their adult feathers. The young are yellowish tan or grayish and very fuzzy. Once they reach adult size, their parents drive them away to establish lives of their own. The life spans of cranes vary considerably. Sandhill cranes rarely live more than 20 years. One Siberian crane (Grus leucogeranus ) was known to live 82 years, but 30-40 years is more usual.
While at their nesting site, most cranes go through a period of molting, or losing their feathers. Some of them have a period of up to a month during which so many feathers have been shed they are flightless.
Species of cranes
The largest crane, and the rarest Asian crane, is the red-crowned, or Japanese, crane (Grus japonicus ). This bird can weigh up to 25 lb (11.4 kg). It has vivid red feathers on the top of its head, but its body is snowy white. It appears to have a black tail, but actually, these feathers are the tips of its wings. Although formerly widespread, the red-crowned crane is now reduced to very small populations in eastern Asia (this species breeds in Russia, and winters in China, Japan, North Korea, and South Korea). In 1952, this crane became Japan’s national bird. There are fewer than about 2, 400 of these birds left in the wild.
The smallest crane is the demoiselle crane (Anthropoides virgo ) of Europe and North Africa. It has white ear tufts that stretch backward from its eyes and hang off the back of the head. Demoiselle cranes live on drier ground than other cranes. The blue crane (A. paradisea ) of Africa has wingtip feathers that reach backward and to the ground, like a bustle. These two cranes do not nest by water, but in grasslands or even semiarid land. The blue crane is the national bird of South Africa. It has the surprising ability when excited, of puffing out its cheeks until its head looks frightening.
The tallest crane is the sarus crane (G. antigone )of India, Cambodia, Nepal, Vietnam, and northern Australia. Standing 6 ft (2 m) tall, it is a gray bird with a head and throat of vivid red. The red color ends abruptly in a straight line around the white neck. This species is among the least social of cranes, and it becomes aggressive when nesting.
A frequent resident of zoos is the crowned crane (Balearica pavonina ) of Africa, which has a beautiful puff of golden feathers coming from the back of the head. It has a red wattle beneath its black and white head, a light gray neck, dark gray back and tail, and white, sometimes yellowish, wings. The West African subspecies has a black neck instead of gray and lacks the red wattle.
The rare black-necked, or Tibetan crane (Grus nigricollis ), of the Himalayas breeds on the high plateau of Tibet. It migrates to the valleys of southwest China and Bhutan to spend the winter. The black-necked crane is a medium-sized crane with a stocky appearance; it has a larger body and shorter neck and legs than related species, perhaps as an adaptation to the cold climate of the Tibetan plateau. This crane has a black neck and head, plus a striking black trailing edge to its wings. A golden circle around the eye makes the eye look enormous against the black feathers. It is estimated that about 8, 000 black-necked cranes survive in the wild.
The seriously endangered Siberian crane is as beautiful as it is rare, with long reddish pink legs, a red-orange face, and a snowy white body with black areas on its wings. This crane breeds only at two locations in Siberia and winters in China, India, and Iran. Only about 3, 200 of these birds are left.
Whooping crane
The whooping crane (Grus americana ) is the rarest crane and the tallest American bird. This crane stands 5 ft (1.5 m) tall and has a wingspan of 7 ft (2.1 m). Adolescent birds have a golden-yellow neck, back, and beak, with golden edges to the black-tipped wings. By adulthood, only the wing tips are black; the rest of the bird is white except for the crown of the head and cheeks, and part of the long, pointed beak, all of which are red.
The population of the whooping crane had declined to only 14 in 1938. The population decline of this species was mostly caused by hunting and habitat loss. In 1937, the wintering area of the whooping crane on the Gulf coast of Texas was protected as Aransas National Wildlife Refuge. In the meantime, some of the few remaining whooping cranes had been taken into captivity. Each egg that was laid was carefully incubated, but few of the young survived. Then, a nesting area was discovered in Wood Buffalo National Park in northwestern Canada. Whoopers generally lay two olive-colored eggs, but only one of them hatches. Canadian wildlife biologists began removing one egg from wild nests. Most of the eggs were hatched in an incubator, while others were placed into the nests of wild sandhill cranes, which served as foster parents.
KEY TERMS
Wattle— Loose flesh, often colored red, that hangs from the chin of certain cranes.
Captive-reared birds have been returned to the wild. This, coupled with careful protection of the wild birds, has allowed the numbers of whooping cranes to gradually increase. By 2004, about 200 whooping cranes existed in the wild with about 150 additional birds in captive flocks. However, the species remains perilously endangered.
Sandhill crane
Sandhill cranes are smaller than whooping cranes. They are generally light-gray in color, with a red crown, black legs, and white cheeks. There are large breeding populations in Siberia, Alaska, and northern Canada east of James Bay, as well as in the western and central United States. There are six subspecies of sandhill crane. Three of them—the greater, lesser, and Canadian sandhill cranes—are migratory birds. The other three—Florida, Mississippi, and Cuban—do not migrate. The lesser sandhill, which is the smallest subspecies (less than 4 ft (1.2 m) tall and weighing no more than 8 lb [3.6 kg]), migrates the greatest distance. Many birds that winter in Texas and northern Mexico nest in Siberia.
The populations of sandhill cranes were greatly reduced by hunting and habitat loss in the 1930s and 1940s. However, wherever protected, they have been making a good comeback. One population in Indiana increased from 35 to 14, 000 over a 40-year period. In one of the most amazing sights in nature, perhaps half a million sandhill cranes land on the sandbars of the Platte River in Nebraska while they are migrating.
Resources
BOOKS
del Hoyo, J., A. Elliott, and J. Sargatal. Handbook of the Birds of the World. Vol. 3, Hoatzin to Auks. Barcelona: Lynx Edicions, 1996.
Forshaw, Joseph. Encyclopedia of Birds. 2nd ed. New York: Academic Press, 1998.
Grooms, Steve. The Cry of the Sandhill Crane. Minocqua, WI: NorthWord Press, 1992.
Katz, Barbara. So Cranes May Dance: A Rescue from the Brink of Extinction. Chicago: Chicago Review, 1993.
Matthiessen, Peter and Robert Bateman. The Birds of Heaven: Travels with Cranes. New York: North Point Press, 2001.
Meine, Curt D., and George Archibald, eds. The Cranes: Status Survey and Conservation Action Plan. Cambridge: IUCN Publications Service, 1996.
OTHER
International Crane Foundation. <http://www.savingcranes. org/> (accessed October 13, 2006).
Jean Blashfield
Cranes
Cranes
Cranes are tall, wading birds known for their beauty, elaborate courtship dances, and voices that boom across their wetland habitat . Their family Gruidae, is among the oldest on Earth . Today 15 crane species are found throughout the world, except in South America and Antarctica . Two species, the whooping crane (Grus americana) and the sandhill crane (G. canadensis) are found in North America . Cranes belong to order Gruiformes, which also includes rails , coots, trumpeters, and the limpkin.
Cranes have long legs, a long neck, and a narrow, tapered bill. Most of them have a featherless spot on the top of the head that exposes colored skin. Some have wattles, or flaps of flesh, growing from the chin. The wattled crane (Bugeranus carunculatus) of eastern and southern Africa has very large wattles. This bird looks more like a chunky stork than a typical crane. Although cranes do look rather like storks and herons , those birds have a toe that points backward, enabling them to grasp a tree branch while perching. Cranes have a backward toe, but in all except the crowned crane (Balearica) it is raised up off the ground and of no use in grasping branches. Crowned cranes are able to perch in trees like storks.
Most cranes migrate fairly long distances to their nesting sites. Their large, strong wings allow them, once airborne, to glide on air currents, taking some of the strain out of the long trip. When flying, cranes stretch their neck and legs straight out, making a long straight body-line. They can cruise at speeds of about 45 mph (72 kph).
Cranes are highly vocal birds. They make many different sounds, from a low, almost purring sound, apparently of contentment, to a loud, high-pitched call that announces to other birds one is about to take flight. Mating pairs of cranes will often point their beaks to the sky and make long, dramatic calls that have been called unison calls or bonding calls. Cranes have a long windpipe that gives volume to their calls.
Cranes eat grains, especially liking waste corn and wheat found in harvested fields. They also eat invertebrates they catch in the water . Both in water and on land, cranes often stand on one foot, tucking the other under a wing.
Dancing and mating
Cranes are noted for their amazing dances that bond individual males and females together. These dances are elaborate and ballet-like, and are among the most intricate and beautiful in the animal kingdom. The cranes bow, leap high into the air, and twirl with their wings held out like a skirt. However, this wonderful dance is not only a courtship dance because once a pair has bonded, they are mated for life. Cranes dance at other times, too, possibly as a way of relieving frustration, which might otherwise erupt into aggression. They also appear to dance for pleasure. Very young cranes start dancing with excitement.
A pair of cranes construct a raised nest of dried grasses by water. Either parent might start incubating as soon as the first egg is laid, although they usually lay two eggs. Crowned cranes often lay three eggs. The eggs hatch after about 28-31 days of incubation. Both parents feed the chicks and take care of them long past the time that they grow their adult feathers. The young are yellowish tan or grayish and very fuzzy. Once they reach adult size, their parents drive them away to establish lives of their own. The life spans of cranes vary considerably. Sandhill cranes rarely live more than 20 years. One Siberian crane (Bugeranus leucogeranus) was known to live 82 years, but 30-40 years is more usual.
While at their nesting site, most cranes go through a period of molting, or losing their feathers. Some of them have a period of up to a month during which so many feathers have been shed they are flightless.
Species of cranes
The largest crane, and the rarest Asian crane, is the red-crowned, or Japanese, crane (Grus japonicus). This bird can weigh up to 25 lb (11.4 kg). It has vivid red feathers on the top of its head, but its body is snowy white. It appears to have a black tail, but actually, these feathers are the tips of its wings. Although formerly widespread, the red-crowned crane is now reduced to very small populations in eastern Asia (this species breeds in Russia, and winters in China, Japan, North Korea, and South Korea). In 1952, this crane became Japan's national bird. There are fewer than about 1,200 of these birds left in the wild.
The smallest crane is the demoiselle crane (Anthropoides virgo) of Europe and North Africa. It has white ear tufts that stretch backward from its eyes and hang off the back of the head. Demoiselle cranes live on drier ground than other cranes. The blue crane (A. paradisea) of Africa has wingtip feathers that reach backward and to the ground, like a bustle. These two cranes do not nest by water, but in grasslands or even semiarid land. The blue crane is the national bird of South Africa. It has the surprising ability when excited, of puffing out its cheeks until its head looks frightening.
The tallest crane is the sarus crane (G. antigone) of India, Cambodia, Nepal, Vietnam, and northern Australia . Standing 6 ft (2 m) tall, it is a gray bird with a head and throat of vivid red. The red color ends abruptly in a straight line around the white neck. This species is among the least social of cranes, and it becomes aggressive when nesting.
A frequent resident of zoos is the crowned crane (Balearica pavonina) of Africa, which has a beautiful puff of golden feathers coming from the back of the head. It has a red wattle beneath its black and white head, a light gray neck, dark gray back and tail, and white, sometimes yellowish, wings. The West African subspecies has a black neck instead of gray and lacks the red wattle.
The rare black-necked, or Tibetan crane (Grus nigricollis) of the Himalayas breeds on the high plateau of Tibet. It migrates to the valleys of southwest China and Bhutan to spend the winter. The black-necked crane is a medium-sized crane with a stocky appearance; it has a larger body and shorter neck and legs than related species, perhaps as an adaptation to the cold climate of the Tibetan plateau. This crane has a black neck and head, plus a striking black trailing edge to its wings. A golden circle around the eye makes the eye look enormous against the black feathers. It is estimated that about 5,500 black-necked cranes survive in the wild.
The seriously endangered Siberian crane is as beautiful as it is rare, with long reddish pink legs, a red-orange face, and a snowy white body with black areas on its wings. This crane breeds only at two locations in Siberia and winters in China, India, and Iran. Only a few thousand of these birds are left.
Whooping crane
The whooping crane (Grus americana) is the rarest crane and the tallest American bird. This crane stands 5 ft (1.5 m) tall and has a wingspan of 7 ft (2.1 m). Adolescent birds have a golden-yellow neck, back, and beak, with golden edges to the black-tipped wings. By adulthood, only the wing tips are black; the rest of the bird is white except for the crown of the head and cheeks, and part of the long, pointed beak, all of which are red.
The population of the whooping crane was down to only 16 in 1941. The population decline of this species was mostly caused by hunting and habitat loss. In 1937, the wintering area of the whooping crane on the Gulf coast of Texas was protected as Aransas National Wildlife Refuge. In the meantime, some of the few remaining whooping cranes had been taken into captivity. Each egg that was laid was carefully incubated, but few of the young survived. Then, a nesting area was discovered inside Wood Buffalo National Park in northwestern Canada. Whoopers generally lay two olive-colored eggs, but only one of them hatches. Canadian wildlife biologists began removing one egg from wild nests. Most of the eggs were hatched in an incubator, while others were placed into the nests of wild sandhill cranes, which served as foster parents. Captive-reared birds have been returned to the wild. This, coupled with careful protection of the wild birds, has allowed the numbers of whooping cranes to gradually increase. By 1995, several hundred whooping cranes existed. However, the species remains perilously endangered.
Sandhill crane
Sandhill cranes are smaller than whooping cranes. They are generally light-gray in color, with a red crown, black legs, and white cheeks. There are large breeding populations in Siberia, Alaska, and northern Canada east of James Bay, as well as in the western and central United States. There are six subspecies of sandhill crane. Three of them—the greater, lesser, and Canadian sandhill cranes—are migratory birds. The other three—Florida, Mississippi, and Cuban—do not migrate. The lesser sandhill, which is the smallest subspecies (less than 4 ft (1.2 m) tall and weighing no more than 8 lb (3.6 kg)) migrates the greatest distance . Many birds that winter in Texas and northern Mexico nest in Siberia.
The populations of sandhill cranes were greatly reduced by hunting and habitat loss in the 1930s and 1940s. However, wherever protected, they have been making a good comeback. One population in Indiana increased from 35 to 14,000 over a 40-year period. In one of the most amazing sights in nature, perhaps half a million sandhill cranes land on the sandbars of the Platte River in Nebraska while they are migrating.
Resources
books
Forshaw, Joseph. Encyclopedia of Birds. New York: Academic Press, 1998.
Friedman, Judy. Operation Siberian Crane: The Story Behind the International Effort to Save an Amazing Bird. New York: Dillon Press, 1992.
Grooms, Steve. The Cry of the Sandhill Crane. Minocqua, WI: NorthWord Press, 1992.
Horn, Gabriel. The Crane. New York: Crestwood House, 1988.
Katz, Barbara. So Cranes May Dance: A Rescue from the Brink of Extinction. Chicago: Chicago Review, 1993.
Jean Blashfield
crane
crane1 / krān/ •
n. a large, tall machine used for moving heavy objects, typically by suspending them from a projecting arm or beam. ∎ a metal arm fastened inside a fireplace for holding cooking pots. ∎ a moving platform supporting a television or movie camera.•
v. 1. [intr.] stretch out one's neck in order to see something: she craned forward to look more clearly. ∎ [tr.] stretch out (one's neck) in this way.2. [tr.] move (a heavy object) with a crane.crane (machine).eps"/>
crane
crane2 • n. a tall, long-legged, long-necked bird (Grus and other genera, family Gruidae), typically with white or gray plumage.