Eurasian crane

The common crane (Grus grus), also known as the Eurasian crane, is a bird of the family Gruidae, the cranes. A medium-sized species, it is the only crane commonly found in Europe besides the demoiselle crane (Anthropoides virgo). Along with the sandhill (Grus canadensis) and demoiselle cranes and the brolga (Grus rubicunda), it is one of only four crane species not currently classified as threatened with extinction or conservation dependent on the species level. Despite the species' large numbers, local extinctions and extirpations have taken place in part of its range, and an ongoing reintroduction project is underway in the United Kingdom. The first formal description of the common crane was by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Ardea grus. The current genus Grus was erected by the French zoologist Mathurin Jacques Brisson in 1760. Grus is the Latin word for a 'crane'. The common crane is a large, stately bird and a medium-sized crane. It is 100–130 cm (39–51 in) long with a 180–240 cm (71–94 in) wingspan. The body weight can range from 3 to 6.1 kg (6.6 to 13.4 lb), with the nominate subspecies averaging around 5.4 kg (12 lb) and the eastern subspecies (G. g. lilfordi) averaging 4.6 kg (10 lb). Among standard measurements, the wing chord is 50.7–60.8 cm (20.0–23.9 in) long, the tarsus is 20.1–25.2 cm (7.9–9.9 in) and the exposed culmen is 9.5–11.6 cm (3.7–4.6 in). This species is slate-grey overall. The forehead and lores are blackish with a bare red crown and a white streak extending from behind the eyes to the upper back. The overall colour is darkest on the back and rump and palest on the breast and wings. The primaries, the tips of secondaries, the alula, the tip of the tail, and the edges of upper tail coverts are all black and the greater coverts droop into explosive plumes. This combination of colouration ultimately distinguishes it from similar species in Asia, like the hooded (G. monacha) and black-necked cranes (G. nigricollis). The juvenile has yellowish-brown tips to its body feathers and lacks the drooping wing feathers and the bright neck pattern of the adult, and has a fully feathered crown. Every two years, before migration, the adult common crane undergoes a complete moult, remaining flightless for six weeks, until the new feathers grow.