Crane (bird) - WikiHQ

Cranes are a type of large bird with long legs and necks in the biological family Gruidae of the order Gruiformes. The family has 15 species placed in four genera which are Antigone, Balearica, Leucogeranus, and Grus. Cranes are solitary during the breeding season, occurring in pairs, but during the non-breeding season, most species are gregarious, forming large flocks where their numbers are sufficient.

They are opportunistic feeders that change their diets according to the season and their own nutrient requirements. They eat a range of items from small rodents, eggs of birds, fish, amphibians, and insects to grain and berries. Cranes construct platform nests in shallow water, and typically lay a clutch of two eggs at a time. Both parents help to rear the young, which remain with them until the next breeding season. Most species of cranes have been affected by human activities and are at the least classified as threatened, if not critically endangered. The plight of the whooping cranes of North America inspired some of the first US legislation to protect endangered species.

Description

thumb|left|The bare area of skin on the face of a [[sandhill crane can change colour or even expand in area when the bird is excited.]]

Cranes are very large birds, often considered the world's tallest flying birds. They range in size from the demoiselle crane, which measures in length, to the sarus crane, which can be up to , although the heaviest is the red-crowned crane, which can weigh prior to migrating. They are long-legged and long-necked birds with streamlined bodies and large, rounded wings. The males and females do not vary in external appearance, but males tend to be slightly larger than females.

The plumage of cranes varies by habitat. Species inhabiting vast, open wetlands tend to have more white in their plumage than do species that inhabit smaller wetlands or forested habitats, which tend to be more grey. These white species are also generally larger. The smaller size and colour of the forest species is thought to help them maintain a less conspicuous profile while nesting; two of these species (the common and sandhill cranes) also daub their feathers with mud which some observers suspect helps them to hide while nesting.

thumb|The long coiled [[Vertebrate trachea|trachea that produces the trumpeting calls of cranes (sarus crane, Antigone antigone)]]

Most crane species have bare patches of skin on their heads and can expand the patches in order to communicate aggression. Species lacking these bare patches use specialized feather tufts to signal similar information.

Also important to communication is the position and length of the trachea. In the two crowned cranes, the trachea is shorter and only slightly impressed upon the bone of the sternum, whereas the trachea of the other species are longer and penetrate the sternum. In some species, the entire sternum is fused to the bony plates of the trachea, and this helps amplify the crane's calls, allowing them to carry for several kilometres.

Taxonomy and systematics

thumb|upright|[[Grey crowned crane (Balearica regulorum) in captivity at Martin Mere, UK]]

thumb|upright|[[Red-crowned cranes (Grus japonensis)]]

The family name Gruidae comes from the genus Grus, this genus name is obtained from the epithet of the common crane which was named Ardea grus by Carl Linnaeus, from the Latin word grus meaning "crane".

The 15 living species of cranes are placed in four genera. A molecular phylogenetic study published in 2010 found that the genus Grus, as then defined, was polyphyletic.

The following cladogram is based on a molecular phylogenetic study by Carey Krajewski and collaborators that was published in 2010.

Evolution

The fossil record of cranes is not very extensive and in need of revision. Many species are based on fragmentary bones of uncertain affinities, and some type species of fossil genera do not belong within Gruidae. 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, although no 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. Cranes are sister taxa to Eogruidae, a lineage of flightless birds; as predicted by the fossil record of true cranes, eogruids were native to the Old World. A species of true crane, Antigone cubensis, has similarly become flightless and ratite-like.

thumb|upright|250px|[[Eogruidae is an extinct lineage of mostly flightless stem-cranes. Pictured is the two-toed Ergilornis.]]

Fossil genera are tentatively assigned to the present-day subfamilies:

Gruinae

Palaeogrus Portis, 1884 (Middle Eocene of Germany and Italy – Middle Miocene of France)
Camusia Seguí, 2002 (Late Miocene of Menorca, Mediterranean)
"Grus" conferta Miller & Sibley, 1942 (Late Miocene/Early Pliocene of Contra Costa County, US)

Sometimes considered Gruidae incertae sedis

Eobalearica Gureev 1949 (Ferghana Late? Eocene of Ferghana, Uzbekistan)
Probalearica Lambrecht. 1933 (Late Oligocene? – Middle Pliocene of Florida, US, France?, Moldavia and Mongolia) – A nomen dubium?
Aramornis Wetmore, 1926 (Sheep Creek Middle Miocene of Snake Creek Quarries, US)

Distribution and habitat

thumb|[[Demoiselle cranes (Grus virgo) in Mongolia: Central Asian populations of this species migrate to Northern India in the winter.]]

The cranes have a cosmopolitan distribution, occurring across most of the world continents. They are absent from Antarctica and, mysteriously, South America. East Asia has the highest crane diversity, with eight species, followed by Africa, which is home to five resident species and wintering populations of a sixth. Australia, Europe, and North America have two regularly occurring species each. Of the four crane genera, Balearica (two species) is restricted to Africa, and Leucogeranus (one species) is restricted to Asia; the other two genera, Grus (including Anthropoides and Bugeranus) and Antigone, are both widespread. The only two species that do not always roost in wetlands are the two African crowned cranes (Balearica), which are the only cranes to roost in trees.

Behaviour and ecology

thumb|[[Common cranes (Grus grus) in Israel: Many species of crane gather in large groups during migration and on their wintering grounds.]]

thumb|Cranes in spring in Mecklenburg (Germany)

The cranes are diurnal birds that vary in their sociality by season and location. During the breeding season, they are territorial and usually remain on their territory all the time. In contrast in the non-breeding season, they tend to be gregarious, forming large flocks to roost, socialize, and in some species feed. Sarus Crane breeding pairs maintain territories throughout the year in south Asia, and non-breeding birds live in flocks that can also be seen throughout the year. Sarus crane trios produce synchronized unison calls called "triets" whose structure is identical to duets of normal pairs, but have a lower frequency. The exact composition of the diet varies by location, season, and availability. Within the wide range of items consumed, some patterns are suggested but require specific investigation to confirm; the shorter-billed species usually feed in drier uplands, while the longer-billed species feed in wetlands. Similar results had been found by acoustic monitoring (sonography/frequency analysis of duet and guard calls) in three breeding areas of common cranes in Germany over 10 years.

Territory sizes also vary depending on location. Tropical species can maintain very small territories, for example sarus cranes in India can breed on territories as small as one hectare where the area is of sufficient quality and disturbance by humans is minimal. Even in areas with a high density of humans, in the absence of directed persecution, species like Sarus Crane maintain territories as small as 5 ha when agricultural crops and landscape conditions are suitable. Trios of Sarus cranes were seen largely in marginal habitats and third birds were young suggesting that third cranes would benefit by gaining experience.

The Greek for crane is (), which gives us the cranesbill, or geranium, which is so named for the resemblance between the fruit of some species and the head and bill of a crane. The crane was a bird of omen in Greek mythology. In the tale of Ibycus and the cranes, a thief attacked Ibycus (a poet of the sixth century BCE) and left him for dead. Ibycus called to a flock of passing cranes to spread the word of his murder, and the Eumenides subsequently summon these cranes to fly over a crowd of mourners calling for Ibycus to be avenged. At the sight of the cranes the killer calls them "the cranes of Ibycus," which is identified as a confession of guilt by crowd, and the killer is dragged off to be judged.

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. A crane holding a stone in its claw is a well-known symbol in heraldry, and is known as a crane in its vigilance. Notably, however, the crest of Clan Cranstoun depicts a sleeping crane still in vigilance and holding the rock in its raised claw.

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. Battles between cranes and dwarf peoples, or geranomachy, is a widespread motif of antiquity and come from China and Arabia at least from the fifth century. Aristotle describes as untruthful an account that the crane carries a touchstone inside it that can be used to test for gold when vomited up.

In pre-modern Ottoman Empire, sultans would sometimes present a piece of crane feather (Turkish: ) to soldiers of any group in the army (janissaries, sipahis, etc.) who performed heroically during a battle. Soldiers would attach this feather to their caps or headgear which would give them some sort of a rank among their peers.

File:Mitsusuke - Zuraw - MNK VI-8203 (503439).jpg|Crane, 18th century, by Mitsusuke (1675–1710), National Museum in Kraków

File:Pine, Plum and Cranes.jpg|Pine, Plum and Cranes, 1759, by Shen Quan (1682—1760), hanging scroll, ink and colour on silk, the Palace Museum, Beijing

File:Main hall, Văn Miếu (Hanoi, Vietnam - 2006).jpg|The "Turtle Carrying Crane on its Back" statue in Văn Miếu (Temple of Literature) in Hà Nội, Vietnam

File:Hdgs Cranes fighting Dwarfes.gif|Dwarves fighting cranes in northern Sweden, a 16th-century drawing by Olaus Magnus

File:Cranes made by Origami paper.jpg|Cranes folded in origami paper

File:Brooklyn Museum - Cranes and Pines - Songha.jpg|Songha (Korean), Cranes and Pines, 19th century. Brooklyn Museum

File:Brooklyn Museum - Tortoise Has New Year's Dream of Crane and Pine - Kôbun Yoshimura.jpg|Tortoise Has New Year's Dream of Crane and Pine, around 1850, Brooklyn Museum

File:Brass Crane Perched on a Tortoise, c. 1800-1894.jpg|Brass Crane Perched on a Tortoise, c. 1800–1894, from the Oxford College Archive of Emory University

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References

External links

Saving Cranes website (ICF)
Craneworld website, mainly in German
individual recognition of cranes using frequency analysis of their calls
Gruidae videos on the Internet Bird Collection
Crane sounds overview on xeno-canto.org
Cranes of the World, by Paul Johnsgard

Myths and lore

Crane Dance at the Tongdosa Temple (archive link, was dead)
Thousand Cranes lore