1 minute read

Cranes

Dancing And Mating, Species Of Cranes, Whooping Crane, Sandhill Crane

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.


Additional topics

Science EncyclopediaScience & Philosophy: Cosine to Cyano group