Sunday, 14 December 2014

Corn crake

Crex crex

(Photo from Hortobágyi Madárpark)

Common name:
corn crake (en); codornizão (pt); râle des genêts (fr); guión de codornices (es); wachtelkönig (de)

Order Gruiformes
Family Rallidae

This species breeds from western Europe, in France, Ireland and Scotland, through central Europe and southern Scandinavia, and into central Asia as far as Kazakhstan, northern China, Mongolia and south-eastern Russia. They migrate south to winter in sob-Saharan Africa, mainly from Tanzania and southern D.R. Congo to Botswana and eastern South Africa.

These birds are 22-30 cm long and have a wingspan of 42-53 cm. They weigh 130-210 g.

The corn crake breeds in open and semi-open habitats, particularly moist, tall grasslands. Originally they would almost certainly have used riverine meadows of Carex-Iris-Typhoides and alpine, coastal and fire-created grasslands with few trees or scrubs, but are now mainly associated with managed agricultural grasslands. Outside the breeding season they mainly use dry grasslands and savannas, also using riverine grasslands, and man-made habitats such as cereal fields, sewage ponds and golf courses.

They feed mainly on invertebrates, including beetles, flies, grasshoppers, dragonflies, earwigs, earthworms, millipedes, spiders, isopods, slugs and snails, but also take small vertebrates such as fishes and amphibians, seeds and shoots.

Corn crakes breed in April-August. They can form seasonal monogamous pairs, but serial polygyny regularly occurs. The nest is made of dead stems and leaves, and placed on the ground among dense vegetation. The female lays 8-12 eggs, which she incubates alone for 14-21 days. The chicks leave the nest within a few hours of hatching and are able to feed themselves after 3-4 days, becoming independent of their mother at about 12 days of age. However, they only start flying 30-35 days after hatching. Each female may raise 1-2 broods per season.

IUCN status - LC (Least Concern)
This species has a very large breeding range and the global population is estimated at 5,45-9,72 million individuals. The population in Russia, which holds the vast majority of the global population, has remained stable even increased over the last decade, with some fluctuations due to extreme weather. However, in Europe the population is predicted to decline by up to 20% over the next decade, due to land use changes. Chick mortality due to mechanized mowing and intensification of grassland management are the main threats affecting corn crakes, although illegal hunting, land abandonment and nest predation by introduced mammals may pose a problem in some areas.

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