Cranes are large, long-legged and long-necked birds of the order Gruiformes, and family Gruidae. Unlike the similar-looking but unrelated herons, cranes fly with necks outstretched, not pulled back. There are representatives of this group on all the continents except Antarctica and South America.
Most species of cranes are at least threatened, if not critically endangered, within their range. The plight of the Whooping Cranes of North America inspired some of the first US legislation to protect endangered species.
They are opportunistic feeders that change their diet according to the season and their own nutrient requirements. They eat a range of items from suitably sized small rodents, fish, amphibians, and insects, to grain, berries, and plants. (The cranberry is so-named for its flowers' resemblance to the neck and head of the crane.)
Most have elaborate and noisy courting displays or "dances". While folklore often states that cranes mate for life, recent scientific research indicates that these birds do change mates over the course of their lifetimes (Hayes 2005), which may last several decades. Cranes construct platform nests in shallow water, and typically lay two eggs at a time. Both parents help to rear the young, which remain with them until the next breeding season.
Some species and/or populations of cranes migrate over long distances, while some do not migrate at all. Cranes are gregarious, forming large flocks where their numbers are sufficient.
SUBFAMILY BALEARICINAE - crowned cranes
SUBFAMILY GRUINAE - typical cranes
The fossil record of cranes leaves much to be desired. Apparently, the subfamilies were well distinct by the Late Eocene (around 35 mya). The present genera are apparently some 20 mya old. Biogeography of known fossil and the living taxa of cranes suggests that the group is probably of (Laurasian?) Old World origin. The extant diversity at the genus level is centered on (eastern) Africa, making it all the more regrettable that no decent fossil record exists from there. On the other hand, it is peculiar that numerous fossils of Ciconiiformes are documented from there; these birds presumably shared much of their habitat with cranes back then already.
Fossil genera are tentatively assigned to the present-day subfamilies:
Sometimes considered Balearicinae
Sometimes considered Gruidae incertae sedis
The supposed Grus prentici is not a true crane; it was eventually placed in the genus Paragrus (Lambrecht 1933:520).
The cranes' beauty and their spectacular mating dances have made them highly symbolic birds in many cultures with records dating back to ancient times. Crane mythology is widely spread and can be found in areas such as the Aegean, South Arabia, China, Korea, Japan and in the Native American cultures of North America. In northern Hokkaidō, the women of the Ainu people performed a crane dance that was captured in 1908 in a photograph by Arnold Genthe. In Korea, a crane dance has been performed in the courtyard of the Tongdosa Temple since the Silla Dynasty (646 CE).
In Mecca, in pre-Islamic South Arabia, the goddesses Allat, Uzza, and Manah, who were believed to be daughters of and intercessors with Allah, were called the "three exalted cranes" (gharaniq, an obscure word on which 'crane' is the usual gloss). See The Satanic Verses for the best-known story regarding these three goddesses.
The Greek for crane is Γερανος (Geranos), which gives us the Cranesbill, or hardy geranium. The crane was a bird of omen. In the tale of Ibycus and the cranes, a thief attacked Ibycus (a poet of the 6th century BCE) and left him for dead. Ibycus called to a flock of passing cranes, who followed the murderer to a theater and hovered over him until, stricken with guilt, he confessed to the crime.
Pliny the Elder wrote that cranes would appoint one of their number to stand guard while they slept. The sentry would hold a stone in its claw, so that if it fell asleep it would drop the stone and waken.
Aristotle describes the migration of cranes in The History of Animals, adding an account of their fights with Pygmies as they wintered near the source of the Nile. He describes as untruthful an account that the crane carries a touchstone inside it that can be used to test for gold when vomited up. (This second story is not altogether implausible, as cranes might ingest appropriate gizzard stones in one locality and regurgitate them in a region where such stone is otherwise scarce)
A crane is considered auspicious in China, Korea, Japan and Vietnam. It is one of the symbols of longevity and is often represented with other symbols of long life, such as pine, bamboo, and the tortoise. Vietnamese people consider crane and dragon to be symbols of their culture. In feudal Japan the crane was protected by the ruling classes and fed by the peasants. When the feudal system was abolished in the Meiji era of the 19th century, the protection of cranes was lost. With effort they have been brought back from the brink of extinction. Japan has named one of their satellites tsuru (crane, the bird). According to tradition, if one folds 1000 origami cranes one's wish for health will be granted. Since the death of Sadako Sasaki this applies to a wish for peace as well.