Wednesday, 19 January 2011

Common crane

Grus grus

Photo by Tarique Sani (Flickr)

Common name:

Order Gruiformes
Family Gruidae

They breed in northern Eurasia, from Scandinavia, Germany and Poland in the west, all the way to eastern Siberia, Mongolia and northern China. There are also some isolated breeding populations further south, in Turkey. They winter in the Iberian Peninsula and along the Mediterranean coast of North Africa, along the Nile basin, in the Middle East, northern India and in southern China.

These large birds are 110-130 cm long and have a wingspan of 220-245 cm. They weigh 5-7 kg.

During the breeding season this species utilizes a wide variety of shallow wetlands, including high altitude, treeless moors or bogs, usually with some standing water, and swampy forest clearings, reedy marshes and rice paddies. In Central Asia the species may use drier forested areas including pine or mixed birch/pine woodland. They winter in floodlands, swampy meadows, shallow sheltered bays, rice paddies, pastures and savanna-like areas such as the open Holm and cork oak woodlands in the Iberian Peninsula.

The common crane is omnivorous. They forage on a wide range of roots, rhizomes, tubers, herbs, pondweeds, berries, cereal grains, peas, olives, acorns and nuts. they hunt various animals including beetles, flies, larval Lepidoptera, snails, earthworms, millipedes, spiders, frogs, lizards, snakes, small mammals, fish and occasionally the eggs and young of small birds.

They start nesting in March-April. The nest is a mound of wetland vegetation, generally placed in or near water in an inaccessible, undisturbed bog, heath, marsh, mire or sedge meadow. The female lays 2 greenish-brown eggs with brown spots. The eggs are incubated by both parents for 29-31 days. The nidifugous chicks leave the nest within 30 h of hatching, but the parents will stay with them, brooding and offering food whenever necessary. the chicks fledge 65-70 days after hatching, but often remain with the parents even on migration and in the wintering areas.

IUCN status - LC (Least Concern)
Both the breeding and non-breeding habitats are threatened by habitat loss and degradation through dam construction, urbanization and agricultural intensification. Increased nest disturbance and nest predation are also a problem in some parts of their range. Pesticide poisoning, collisions with power lines and hunting are threats during migration and winter. Despite these, overall the population trend is uncertain, as some populations are decreasing, while others are increasing, stable or have unknown trends. With a population of 360.000-370.000 individuals and a very large breeding range, the species is not considered threatened at present.

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