22-3-2017 PEGO MARJAL, ALICANTE - COMMON CRANE (Grus grus)

19-2-2017 PEGO MARJAL, ALICANTE - COMMON CRANE (Grus grus)

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 (Grus virgo) and the Siberian crane (Leucogeranus leucogeranus) that only are regular in the far eastern part of the continent. Along with the sandhill crane (Antigone canadensis), demoiselle crane and the brolga (Antigone 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 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).

Males are slightly heavier and larger than females, with weight showing the largest sexual size dimorphism, followed by wing, central toe, and head length in adults and juveniles.

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.

It has a loud trumpeting call, given in flight and display. The call is piercing and can be heard from a considerable distance. It has a dancing display, leaping with wings uplifted, described in detail below.

The common crane breeds in Europe and across the Palearctic to Siberia. By far the largest breeding populations can be found in Russia, Finland and Sweden. It is a rare breeder in southern and western Europe, with larger numbers breeding in the central and eastern parts of the continent. It has reappeared in several western European countries where it had been extirpated as a breeding bird decades or even centuries ago, including the United Kingdom and, since 2021, the Republic of Ireland. In Russia, it breeds as far east at the Chukchi Peninsula. In Asia, the breeding range of the common crane extends as far south as northern China, Turkey and the Caucasus region.

The species is a migrant and common cranes that breed in Europe predominantly winter in Portugal, Spain and northern Africa. Autumn migration is from August to October in the breeding areas, but from late October to early December at the wintering sites. Spring migration starts in February at wintering sites up to early March, but from March through May at the breeding areas. Migration phenology of common cranes is changing due to climate change. Important staging areas occur anywhere from Sweden, the Netherlands and Germany to China (with a large one around the Caspian Sea) and many thousand cranes can be seen in one day in the Autumn. Some birds winter elsewhere in southern Europe, including Portugal and France. During mild winters, some may stay near their breeding locations year-round, even in northwestern Europe. Common cranes that breed in far eastern Europe, including European Russia, winter in the river valleys of Sudan, Ethiopia, Tunisia and Eritrea with smaller numbers in Turkey, northern Israel, Iraq and parts of Iran. The third major wintering region, primarily used by those breeding in central Russia, is in the northern half of the Indian subcontinent, including Pakistan. Minimal wintering also occurs in Burma, Vietnam and Thailand. Lastly, the easternmost breeders winter in eastern China, where they are often the most common crane.ation.

It is a rare visitor to Japan and Korea, mostly blown over from the Chinese wintering population, and is a rare vagrant to western North America, where birds are occasionally seen with flocks of migrating sandhill cranes.

Wetlands are preferred habitats for the cranes.

In Europe, the common crane predominantly breeds in boreal and taiga forest and mixed forests, from an elevation of sea-level to 2,200 m (7,200 ft). In northern climes, it breeds in treeless moors, on bogs, or on dwarf heather habitats, usually where small lakes or pools are also found. In Sweden, breeders are usually found in small, swampy openings amongst pine forests, while in Germany, marshy wetlands are used. Breeding habitat used in Russia are similar, though they can be found nesting in less likely habitat such as steppe and even semi-desert, so long as water is near. Primarily, the largest number of common cranes are found breeding in wooded swamps, bogs and wetlands and seem to require quiet, peaceful environs with minimal human interference. They occur at low density as breeders even where common, typically ranging from 1 to 5 pairs per 100 km2 (39 sq mi).

In winter, this species moves to flooded areas, shallow sheltered bays, and swampy meadows. During the flightless moulting period there is a need for shallow waters or high reed cover for concealment. Later, after the migration period, the birds winter regularly in open country, often on cultivated lands and sometimes also in savanna-like areas, for example on the Iberian Peninsula.

The common crane is omnivorous, as are all cranes. It largely eats plant matter, including roots, rhizomes, tubers, stems, leaves, fruits and seeds. They also commonly eat, when available, pond-weeds, heath berries, peas, potatoes, olives, acorns, cedar nuts and pods of peanuts. Notably amongst the berries consumed, the cranberry, is possibly named after the species.

Animal foods become more important during the summer breeding season and may be the primary food source at that time of year, especially while regurgitating to young. Their animal foods are insects, especially dragonflies, and also snails, earthworms, crabs, spiders, millipedes, woodlice, amphibians, rodents, and small birds.

Common cranes may either forage on land or in shallow water, probing around with their bills for any edible organism. Although crops may locally be damaged by the species, they mostly consume waste grain in winter from previously harvested fields and so actually benefit farmers by cleaning fields for use in the following year. As with other cranes, all foraging (as well as drinking and roosting) is done in small groups, which may variously consist of pairs, family groups or winter flocks.

This species could live up to 30 or 40 years of age. But the data on longevity (43 years) and life expectancy (12 years, N=7 cranes) were published with captive cranes. Common cranes living in the wild must show shorter lives. Successful breeders, the best subjects in the population, are guessed to live on average 12 years. Unsuccessful breeding cranes, therefore, may have shorter lives. Elementary survival analysis with the Euring database reports a life expectancy at birth (LEB) of c. 5 years. This LEB of 5 years was similar to that estimated for other crane species, as for example the Florida sandhill cranes (G. canadensis) (LEB = 7 years). Reports of tagged common cranes have increased rapidly in the last decades.

15-2-2017 PEGO MARJAL, ALICANTE - COMMON CRANE (Grus grus)