Common crane  (Grus grus)

Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix II of CITES (3).

The most widely distributed of all cranes (4), the common crane is a large and impressive waterbird with a long neck, beak and legs (5). The plumage is mainly slate grey, with black flight feathers (2) (5) (6), the innermost of which are greatly elongated, forming a drooping, bushy ‘cloak’ over the tail (5) (6). In contrast, the neck, chin and throat are dark grey to black, with a black forehead and a distinctive white stripe that runs from behind the eye, down the neck and to the upper back. The top of the head bears a red patch of bare skin, and the eye is also bright red or reddish-brown. The juvenile common crane has yellowish-brown tips to its body feathers, lacks the drooping wing feathers and the bright neck pattern of the adult, and has a fully-feathered crown (2) (5) (6) (7). The calls of this species are loud, trumpeting and quite penetrating (2) (5) (6).

The common crane breeds from northern and western Europe, across Europe and Asia, to northern China, northern Mongolia and eastern Siberia. A migratory species, it winters in southern Europe, north and east Africa, the Middle East, India, Pakistan, and southern and eastern China (2) (4) (6) (7). However, in the UK the East Anglian population is non-migratory (8).

This crane uses a wide variety of shallow wetland habitats, including bogs, forested swamps, reedy marshes, meadows, agricultural fields, pastures, shallow sheltered bays, rivers and shallow lakes, grassland, and holm oak woodland (2) (4) (6) (7). It will also use drier areas in Central Asia, as long as water is readily available (4) (6) (9).

The common crane forages by day, probing with its beak or picking up food from both land and water. The diet includes a wide range of plant and animal matter, including roots, shoots, tubers, leaves, grain and nuts, as well as various invertebrate and small vertebrate prey, and occasionally birds’ eggs (2) (4) (6) (9). Outside the breeding season, this crane gathers and migrates in large flocks, but during the breeding season, from April to June, each breeding pair occupies a large nesting territory (4) (6) (9). Breeding pairs are monogamous (4) (6), reinforcing the pair bond with ‘unison calling’, a complex series of coordinated calls given with the head thrown back and the beak pointed skywards (7). All ages and sexes also engage in ‘dancing’, a variety of bows, bobs, leaps, running, and tossing of vegetation, most commonly used in courtship, but also associated with aggression (6) (7).

The nest, which may be used from year to year, is a mound of wetland vegetation, generally placed on the ground in or near water (2) (6) (7) (9). Both the male and female help build the nest and incubate the two eggs, which hatch after 28 to 31 days (2) (4) (6) (7). During this time, the adults may use mud or decaying vegetation to ‘paint’ the upper body and wings reddish brown, an intriguing behaviour that may provide camouflage (6). The chicks have brown plumage, and fledge at around 65 to 70 days, but take between 4 and 6 years to reach maturity (2) (6). Every two years, before migration, the adult common crane undergoes a complete moult, remaining flightless for six weeks, until the new feathers grow (6) (9).

Although still one of the most abundant and widespread cranes, the common crane was wiped out as a breeding species in much of southern and western Europe during recent centuries (2) (4). The main threat to the species comes from habitat loss and degradation, as a result of dam construction, urbanisation, agricultural expansion, and drainage of wetlands (2) (4) (7) (9). Although it has adapted to human settlement in many areas, nest disturbance, continuing changes in land use, and collision with utility lines are still problems, and further threats include persecution due to crop damage, pesticide poisoning, egg collection, and hunting (2) (4) (9). However, despite these threats, and declines in some areas, the species is now recovering in the western parts of its range, where conservation efforts have been most intensive (2) (4).

The common crane is legally protected in most of its range, although stronger enforcement is needed in many areas (4). It is also protected under a range of international legislation (3) (10) (11) (12) (13). Conservation efforts across Europe are coordinated by the European Crane Working Group, and include population monitoring, protection of key migration and wintering habitats, ringing and telemetry studies of migration routes, appropriate habitat management and wetland restoration, and investigations into solving the problem of crop damage (2) (4) (7) (9). The species also plays a valuable role in wetland education projects (2) (4). Although conservation efforts have been less focused outside Europe, the common crane has often benefitted from conservation actions undertaken for other crane species (4).

With the protection and restoration of suitable wetland habitats, the common crane has started to return to many of its former breeding grounds, and reintroductions have also been proposed (4). For example, in the UK the Great Crane Project is hand-rearing common crane chicks, with the aim of re-establishing a wild breeding population in the Somerset Levels and Moors (14) (15). After a 400-year absence, the species has already started to re-colonise other parts of the UK (14) (15), and it is hoped that the sight and sound of this magnificent bird may soon make a welcome return to many more parts of its former range.

To find out more about the conservation of the common crane see:

• International Crane Foundation:
  http://www.savingcranes.org/
• European Crane Working Group:
  http://www.ecwg.org/home_page.html
• Meine, C.D. and Archibald, G.W. (1996) The Cranes: Status Survey and Conservation Action Plan. IUCN, Gland, Switzerland, and Cambridge, UK. Available at:
  http://www.npwrc.usgs.gov/resource/birds/cranes/index.htm
• The Great Crane Project:
  http://www.thegreatcraneproject.org.uk/

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org