Justification of Red List Category
This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (extent of occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is estimated to be increasing therefore it does not approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The global population is estimated to number c.491,000-503,000 individuals (Wetlands International 2015). The European population is estimated at 113,000-185,000 pairs, which equates to 225,000-370,000 mature individuals (BirdLife International 2015). The population is therefore placed in the band 490,000-504,999 individuals.
The overall population trend is increasing, however some populations are decreasing, while others are stable or have unknown trends (Wetlands International 2015). The European population is estimated to be increasing (BirdLife International 2015).
Behaviour This species is fully migratory, although isolated breeding populations east and south of the Black Sea may be resident or only undertake local movements (Snow and Perrins 1998). It usually migrates on a narrow front, utilising two major migration routes (south-west, and south to south-east passages across Europe) and uses regular staging areas (Snow and Perrins 1998). Family groups and non-breeding birds begin to migrate in July, but the majority of the species migrate in early September, arriving in African wintering grounds during October. The species returns to its breeding areas in March (Vegvari 2002), where breeding begins in late April or early May, occasionally up to three weeks earlier in southern areas (Snow and Perrins 1998). It is gregarious for much of the year, migrating in flocks of between 10-50 to 400 birds (Africa) and congregating in groups of few to 1,000 birds in the non-breeding season (Cramp and Simmons 1980, Urban et al. 1986), exceptionally it gathers in flocks of up to 4,000 during the moulting period (Cramp and Simmons 1980). Whilst breeding, pairs are solitary with large nesting territories, although immature and unmated birds may remain in groups of 6-10 individuals (Cramp and Simmons 1980). Every two years adults undergo a complete moulting period, after breeding but before leaving for wintering grounds, throughout which they are flightless for around six weeks (Urban et al. 1986). This species is diurnal, feeding during the day and roosting during the night on the ground or in water in large numbers (the same roost is often used every night, and sometimes every year) (Cramp and Simmons 1980, Urban et al. 1986). Habitat Breeding During the breeding season this species utilises a wide variety of shallow wetlands, including high altitude, treeless moors or bogs (where the main vegetation is Sphagnum moss or Ericaceae) usually with some standing water, and swampy forest clearings, reedy marshes and rice paddies (Cramp and Simmons 1980). The species requires inaccessible ground nesting-sites, so is commonly associated with quaking bogs and other impassible mires, especially in the vicinity of Alnus carr woodland or seasonally flooded riverine forest (Cramp and Simmons 1980). In Central Asia the species may use drier forested areas (such as pine or mixed birch/pine woodland) if water is readily available (Cramp and Simmons 1980), but it generally avoids heavily wooded areas (Urban et al. 1986). The species moults in its breeding habitat after breeding, specifically requiring shallow waters or high reed cover for concealment during this vulnerable flightless period (Cramp and Simmons 1980). Non-breeding The non-breeding wintering and migration habitats of the species include floodland, swampy meadows, shallow sheltered bays, rice paddies (Cramp and Simmons 1980), pastures and savannah-like areas (such as open holm oak woodlands in the Iberian Peninsula) (Meine and Archibald 1996). The species may also be found roosting on mudflats or sandbanks along rivers, lakes and reservoirs during this season (Urban et al. 1986, Meine and Archibald 1996) and undertake flights of up to 20 km (Cramp and Simmons 1980) to forage in agricultural fields (Meine and Archibald 1996, Vegvari 2002) (due to human encroachment and destruction of its preferred habitats) (Cramp and Simmons 1980). Diet The species is omnivorous in both breeding and non-breeding seasons, the plant component of its diet consisting of grass roots and shoots, rhizomes, tubers (e.g. potatoes), the leaves of crops and wild herbs (e.g. brassicas, clover, nettle, chickweed), pondweed, the berries of Empetrum and Vaccinium, cereal grain (e.g. wheat, barley, oats, rye, maize, rice), peas, olives, acorns, cedarnuts, groundnuts Arachis, and the pods of Cajanus (Cramp and Simmons 1980, Urban et al. 1986). Animal matter in this species' diet includes adult (beetles, flies) and larval (Lepidoptera) insects, snails, earthworms, millipedes, spiders, woodlice, frogs, slow-worms, lizards, snakes, small mammals (rodents and shrews), fish and occasionally the eggs and young of small birds (Cramp and Simmons 1980, Urban et al. 1986). Breeding site The nest is a mound of wetland vegetation (which may be re-used from year to year), generally placed in or near water in inaccessible undisturbed bog, heath, marsh, mire (Cramp and Simmons 1980, Urban et al. 1986), or sedge meadow (Malik and Prange 1995). Management information The removal of willow bushes, reeds and bog grass from areas in the Kremmener Luch nature reserve, central Germany, has been successful in providing suitable roosting sites with wide panoramic views which have attracted the species to the area (Malik and Prange 1995). The vegetation was removed during the winter months: willow bushes being cut off and poisoned with arboricid, bog grass being burnt down and reeds being mechanically cut (Malik and Prange 1995). Other management efforts in western Europe include the burial or relocation of utility lines, and programs to encourage the planting of lure crops and the use of waste grain for diversionary feeding (away from agricultural crops) (Meine and Archibald 1996).
In both its breeding and non-breeding ranges this species is principally threatened by habitat loss and degradation through dam construction, urbanisation and agricultural expansion (including changes in land-use, intensification, expanded irrigation systems and conversion of traditional holm oak pastures) (Meine and Archibald 1996). Breeding In parts of its breeding range that are heavily developed the species is threatened by nest disturbance from tourism and recreation which reduces its breeding success by increasing the incidence of successful nest predation by corvids, wild boar and foxes (Meine and Archibald 1996). Egg collecting is also a threat to the breeding population in Turkey (Meine and Archibald 1996). Non-breeding Along its migrational routes and in its wintering grounds the Common Crane is particularly threatened by habitat fragmentation and the loss of many smaller traditional feeding and roosting sites, leading to increasing concentrations of large flocks in smaller areas, and therefore increased competition (Cramp and Simmons 1980, Alonso et al. 1994, Meine and Archibald 1996). Pesticide poisoning may also be affecting cranes along migration routes and in some wintering areas, especially where they depend primarily on grain from agricultural fields (Meine and Archibald 1996). Collisions with utility lines are frequent in highly developed areas along migration routes and in winter ranges (collisions being the leading cause of adult mortality at wintering areas in Spain) (Meine and Archibald 1996). Hunting is a significant threat to this species on migration (e.g. through Afghanistan and Pakistan) (Meine and Archibald 1996, Nawaz et al. 2006) and illegal shooting has been identified as a problem in other areas (including Portugal, southeast Europe, Egypt and Sudan) (Meine and Archibald 1996).
Conservation Actions Underway
Bern Convention Appendix II. EU Birds Directive Annex I. CMS Appendix II. The following information refers to the species's European range only: The species is legally protected across all of its European range, although stronger enforcement is needed in many areas. The European Crane Working Group (ECWG) has coordinated conservation activities including research, monitoring, colour banding, habitat protection, education, and recommended changes in agricultural policy, since the mid-1980s. Some breeding areas are within protected areas in Russia, Ukraine, Poland, Hungary, Spain and Germany. Intensive habitat management in western Europe, including the creation and restoration of wetlands, agreements with private land owners to protect key resting and wintering habitats, clearing of dense vegetation from roosting areas, development of habitat management plans for protected areas, burial or relocation of utility lines, programs to encourage planting of lure crops and use of waste grain for diversionary feeding; and compensation programs for farmers suffering crop damage have resulted in breeding pairs resettling former breeding habitats. Breeding populations have been most closely monitored in Scandinavia, the Baltic nations, Poland, and Germany and in recent years, surveys have been conducted regularly at key staging and wintering areas in Russia, Spain, Germany, France, Portugal, Hungary, Sweden and Estonia. Intensive research in Europe has focused on demographics, life history, feeding and wintering behaviour, and habitat and conservation needs (Meine and Archibald 1996). Reintroduction of the species to the southwest U.K. began in 2010 with released birds establishing territories and nests (The Great Crane Project 2014).
Conservation Actions Proposed
The following information refers to the species's European range only: Legal protection of wetlands and other habitats in the species's breeding grounds, along its migratory routes, and in its wintering grounds should be strengthened. Cooperative international conservation programmes involving countries along the main migratory routes should be established and international research expanded. Protected areas at important breeding, staging, resting, and wintering areas should be established or expanded and enforcement and management of existing protected areas strengthened. Other measures include the continuation of research and censusing, addressing crop degradation problems, education and captive propagation and release (Meine and Archibald 1996).
Text account compilers
Ekstrom, J., Butchart, S., Malpas, L., Jones, V., Symes, A., Ashpole, J
BirdLife International (2019) Species factsheet: Grus grus. Downloaded from http://www.birdlife.org on 13/10/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 13/10/2019.