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Distribution, Habitat and Food

Crane Distribution Crane Distribution (c) Lorcan O'Toole

The Eurasian Crane breeds in wetlands of the Eurasian boreal and temperate forest zones, from lowlands up to 2200 m, often foraging in nearby upland areas. Across this extensive breeding range, the species nests in a variety of shallow (20-40 cm) freshwater wetland types, including open marshes, forested swamps (especially birch and alder swamps), sedge meadows, lake edges, and bogs. In central Asia, drier habitats (even semi desert areas) may be used if water is available. Former breeding habitats in southern Europe were primarily permanent, densely vegetated marshes. Eurasian Cranes are omnivorous, probing and picking for a wide range of plant and animal foods both on dry land and in wetlands. Even during the chick-rearing period, however, they prefer to forage in upland areas (including agricultural fields) with short vegetation. During this period, animal foods-worms, snails, insects, arthropods, frogs, lizards, snakes, rodents-are very important (especially for the chicks) and tend to be more frequently consumed.

Eurasian Crane current Distribution Worldwide.
On their wintering grounds, Eurasian Cranes roost in wetlands and other shallow waters and forage for waste and sown grain, acorns, insects, and other foods in agricultural fields, pastures, and other upland habitats. In general, plant items are much more important in the winter diet. Feeding and roosting habitats are highly varied throughout the species’ widely scattered wintering grounds: open holm oak woodlands (dehesas and montados), cereal fields, and shallow wetlands in the Iberian Peninsula; lakebeds, large river valleys, and upland grasslands in North and East Africa; shallow lakes, reservoir edges, and coastal marshes in the Middle East and North Africa; agricultural fields, grasslands, reservoir margins, and other shallow water bodies in India; and shallow lakes, agricultural fields, and deltaic wetlands in China.

Cranes are generalists and opportunists, feeding on a remarkably wide variety of plant and animal foods. Among cranes that use upland areas, the diet includes seeds, leaves, acorns, nuts, berries, fruits, waste grains, worms, snails, grasshoppers, beetles, other insects, snakes, lizards, rodents and other small mammals, and even small birds. Wetland food items include the roots, bulbs, rhizomes, tubers, sprouts, stems, and seeds of submergent and emergent plants, and molluscs, aquatic insects, crustaceans, small fish, and frogs. Cranes readily shift their feeding strategies on a daily or seasonal basis to take advantage of available food items. For example, Eurasian Cranes wintering on the Iberian Peninsula subsist primarily on cereal grains in the early part of the winter, switch to acorns of the holm oak in mid-winter, and may turn again to germinating cereals and legumes in the late winter. (SEE URL: http://www.npwrc.usgs.gov/resource/birds/cranes/grusgrus.htm)

Cranes can cause trouble for farmers and their crops, by snacking on germinating seeds of crops. They eat corn, wheat, oats and barley seeds and seedlings and their kernels underground. Large flocks of the non-nesting and highly mobile birds are especially destructive, poking their beaks deep into the ground, even ripping out young corn plants to get to the tasty morsels underneath.

Biologists at the International Crane Foundation, based in Baraboo, USA, state, "You can think of the non-nesting birds as teenagers out causing trouble. The birds can virtually pick a 10- to 20-acre field free of corn, and there are typically 30,000 seeds planted per acre." But coating the seed with a commercially available formula, that guards against pests, and that deters birds appears to solve the problem - cranes are now welcome visitors in the cornfields in America using this method. (SEE www.jstor.org/pss/3801232 and www.jsonline.com/news/wisconsin/52481892.html)

Favoured wintering grounds in Europe show the regular build up of passage birds or over-wintering birds from early October through till late February. One site in France can occasionally hold up to 60,000 cranes. Any such passage site or wintering site, possibly in the south of Ireland in large original sheltered wetlands were likely to have witnessed several thousand Cranes on occasion in early Christian times. It is extremely likely that such memorable events would have merited local comment and led to lasting recognition in place names. (See http://www.ecwg.org/NEWS/V_ECW_(Preliminary%20List).htm)

Its food is primarily plant material, including roots, leaves, stems, rhizomes, tubers, fruit, seeds and grain. Animal prey also taken and may predominate at times during the summer. Food is taken from the ground, shallow water or low vegetation while standing or walking slowly. Also probes and breaks up surface of the soil with bill to obtain plant and animal food matter beneath. The plant material includes fresh grass shoots, leaves of wild herbs and crops, pondweed, cereal grain and berries from Empetrum (crowberry) and Vaccinium (bilberry, cowberry and cranberry). Its animal prey includes mainly some of the commoner insects’ families, snails, earthworms, millipedes, spiders and woodlice. But they also take frogs, small rodents and occasionally fish and the eggs and young of small birds. (SEE URL: http://www.npwrc.usgs.gov/resource/birds/cranes/grusgrus.htm). It is worth noting that the Grey Heron diet is predominantly fish and a few waterside birds, animals and invertebrates. Grey Herons do not take vegetative matter.