Corn Crake

Corn Crake
	Corn Corn ( Crex crex ) singing ? / i;
Systematics
Class :	Birds (aves)
Order :	Crane birds (Gruiformes)
Family :	Rallen (Rallidae)
Genre :	Corn Corn ( Crex )
Type :	Corn Crake
Scientific name
	Crex crex
	( Linnaeus , 1758)

Depiction of the corncrake with a young bird

The corncrake ( Crex crex ), also called meadow rail or meadow creaker , is the only species of the Crex genus in Europe within the railing birds (Rallidae). The species is monotypical . The genus Crex includes only a second, also monotypical species, the savanna rail ( Crex egregia ), which occurs in sub-Saharan Africa.

Appearance

The king corn is slightly larger than a quail . It has a yellowish-brown basic color of the upper plumage, with the feather centers being darkly colored. The underside is very light brown to whitish. The corncrake is banded rusty brown on the flanks. During the breeding season, the males are colored gray-blue on the cheeks and sides of the neck. In flight, the claw-like drooping legs and the chestnut-brown top of the wings are noticeable. When running, the extremely hidden and solitary bird looks relatively long-necked and long-legged.

The sexes are very similar, the gray color of the cheeks is more indistinct in females. The plumage of the young birds is also very similar to the adult dress; He also lacks the gray coloring on the head and the rust-brown banding on the flanks.

Locomotion

Corncocks allow intruders to get very close, then suddenly fly up and quickly fall back into cover. The flight seems clumsy to the observer: the wing movements are slow, with far reaching strokes. The long legs droop. As a rule, it does not fly high, but only flies a little above the vegetation and lands after five to seven meters. In the dense grasses that he prefers to colonize, he moves skillfully with frequent changes of direction. He overcomes free, open water surfaces by flying.

voice

The call of the male is an unmistakable, creaky double element : rerrp-rerrp (similar to how you run your thumbnail over the rough teeth of a comb). The call, which under favorable conditions carries up to 1 km, is often repeated for hours. Mostly it is performed from the ground, more rarely from waiting, exceptionally also in flight. It apparently serves to delimit the territory and is therefore mainly heard at the beginning of the mating season, but overall from the beginning of May to the beginning of July.

The main singing period lasts about two to four weeks. It begins about 34 days after arrival at the hatchery and ends with the egg-laying. After hatching, there may be another brief phase of call activity.

The corncrake calls out on the train, both in autumn and in spring. Often even in completely unsuitable habitats . In the winter quarters he apparently remains silent.

Corncracks usually call at night. The main call activity begins at dusk (approx. 10 p.m.) and lasts until the early hours of the morning, i.e. until sunrise (approx. 4:30 a.m.). Often the call can then be heard continuously. The males are particularly persistent and happy to shout on warm, windless nights and when several males are mutually stimulated.

Usually only single calls can be heard during the day, especially often in rainy weather. Often this is the only indication of the presence of a corncrake.

Other vocal expressions such as growling or grunting squeaks, "blaring drums" or high-pitched beeps are only known from captivity and are only incompletely described. The begging call of the boys is vaguely reminiscent of a quiet sparrow pricking. Trills can also be heard from these when excited.

Food and subsistence

The corncrake searches for and captures its food exclusively on the ground. The species is omnivorous with an excess of animal food. Especially insects such as are grasshoppers , beetles , mosquitoes , dragonflies and flies captured. Small frogs , occasionally small rodents and earthworms also belong to the prey spectrum of the species. A little less than 20 percent of the total diet is vegetarian complementary food, it mainly consists of green parts of plants and seeds.

The food is taken from the ground continuously or hopping or read from plants. Indigestible food residues are excreted in about one centimeter long spittle balls .

Reproduction

Gelege, Museum Wiesbaden collection

Corncocks can breed from the first year of life. Both sexes live in successive polygamy and can mate several times in one breeding season. Broods occur from late April (rare exceptions) to early August. The nest is often a hollow, only slightly dug out and lined with grasses and stalks, sometimes also with moss, with a diameter of 12 to 15 cm. The clutches comprise 6–19 eggs, with the very large clutches apparently coming from two females. The clutch is incubated by the female alone. The pair bond ends with the oviposition. When the clutch is complete, it is incubated. After 16 to 19 days, the young hatch synchronously. The hatched young flee the nest and are fed by the female for 3 to 4 days. After that they are only led by the female. At 34 to 38 days, the youngsters are fully capable of flying, but are already independent beforehand. There are two annual broods, with additional clutches occurring. After the first mating there is a sometimes extensive change of area, especially with males. The mortality in the first year of life is very high, according to studies in Great Britain it is likely to be 70–80%.

distribution

Spread of the Corn Crake:

Breeding areas

migration

Wintering areas

Resettlement areas

The species is distributed across a wide strip from Western Europe to Western China and the Baikal area . In Western, Northwestern and Central Europe the occurrences are extremely patchy, while in Eastern and Southeastern Europe as well as in the Asian distribution areas there are quite dense populations rich in individuals. With the exception of a few isolated island occurrences in the southern Caspian region and in the eastern Mediterranean region, the southern limit of distribution is approximately at the 40th parallel. To the north, Scotland , central Scandinavia and the tundra zone of Siberia are reached close to the Arctic Circle.

In general, the corn corn is a breeding bird of the planar and colline levels . In the Caucasus and Altai , however, breeding occurrences are known at altitudes above 2500 meters.

habitat

Corn corn in typical habitat

The corncrake is particularly widespread in habitats with spring or winter floods, for example in sedges , pipegrass or iris meadows . It needs vegetation rich in cover with a height of at least 35 cm. The species can also colonize extensively used agricultural areas, in particular pasture meadows and silting areas. Shores of salt or brackish water areas are generally avoided, but the species evidently breeded in dune areas on the East Frisian Islands until the beginning of the 20th century .

Nest locations are often vegetation islands with very dense vegetation - for example with pipe grass or nettles . Locations near bushes are preferred - but the species also breeds in grain fields or meadows if there is enough cover.

hikes

Despite its seemingly awkward flight, it is a downright long-haul migrant with wintering areas in eastern Africa southwards to the Cape region. Western birds can already overwinter in Spain or northwestern Africa. Central European birds seem to pull loops , but the migratory behavior of the species is not known in detail. The arrival in the Central European breeding areas is seldom before the beginning of May, the departure already begins in mid-August.

Danger

The corn corn is classified as endangered in the Red List of Germany's breeding birds.

The stock situation of this species must be viewed in a very differentiated manner. In Central Europe, stocks declined rapidly in some cases, but have been recovering slightly for about 10 years or at least have remained stable. Habitat destruction through extensive drainage of former wetlands, bringing forward the mowing dates and extensive, quickly performed mechanical mowing were decisive for this development. In addition, in the last decade there has been an increasing number of severe impairments in the wintering areas, caused primarily by environmental changes and the introduction of pesticides . The losses during the train, partly due to readjustments, partly due to accidents (high-voltage lines), are considerable. This trend appears to be less negative in north-western Europe and Scandinavia.

In southeast Europe and in the Asian distribution areas, the species is likely to be much more common than previously assumed. In any case, global population estimates have been revised upwards considerably since 1996.

The IUCN lists the corn crake as not endangered . However, a decline due to the destruction of the natural habitat is to be expected. The corn corn is also one of the species affected by climate change. A research team that, on behalf of the British Environmental Protection Agency and the RSPB, examined the future development of the distribution of birds on the basis of climate models assumes that the distribution area in Central and Eastern Europe will be significantly fragmented by the end of the 21st century. According to these prognoses, the main distribution shifts significantly to the northeast.

In some areas of Europe, compensation payments are made to farmers for subsequent mowing of corncrake fields. The funds mostly come from EU funds , states and federal states for environmentally friendly agriculture or from nature conservation associations.

Corn Crake and Human

Etymology and naming

The zoological name Crex crex refers to ancient Greek κρέξ krex than the onomatopoeic term for this Rail; in the binomial of the only species of the genus Crex in Europe , it appears twice and thus resembles the repetitive call.

The German name "Wachtelkönig" can be traced back to earlier ideas that the Wachtelkönig is the leader of the quail. In earlier times it was often caught with quail, and because it is slightly larger, it was called the king of the quail by farmers and hunters. In the vernacular , the corncrake is also known as "Wiesenknarre", "Schnärz", "Schnerper", "Schnarrwachtel", "Wiesensumpfhuhn", "Creaking pipe chicken", "Wiesenrale", "Tau- und Kornschnarre", "Grasräsche", "Arpschnarp" "Ginsterralle", "Mähderhex", "Alter Knecht", "Lazy Maid", "Kreßler", "Ackerhennick", "Grauer Kaspar", "Feldwächter", "Wiesenläufer" and "-schnarcher", "Grasrutscher", "Knarrer" "," Eggenschär "," Schonk "," Stroh- und G'hackschneider "," Nachtschreier "," Stosch "," Grasschnepf "," Sensenwetzer "," Knecht mäh! "," Bütsche "," Kornhühnel "," Gnarrendart ”,“ Gerstenratzer ”, in Swabian also“ Heckschnärr ”. Many of these names are obviously related to the characteristic calls, others reflect the habitat.

regional customs

For residents of Nürtingen , the term "Heckschnärren" has been handed down as an earlier local name . Therefore the sculpture of a corncrake adorns the town hall facade. Since 1984 the Nürtingen SPD has been awarding the “Egg of the Heckschnärre” on Ash Wednesday as an award “to particularly committed citizens” who “defend their territory upright”.

literature

Urs N. Glutz from Blotzheim u. a .: Galliformes and Gruiformes. 2nd Edition. Aula, Wiesbaden 1994, ISBN 3-89104-561-1 ( Handbook of the birds of Central Europe . Volume 5) pp. 444-468.
Hans-Günther Bauer, Peter Berthold: The breeding birds of Central Europe. Aula, Wiesbaden 1997, ISBN 3-89104-587-5 , pp. 148-150 (more recent information on holdings and distribution).
Hans-Günther Bauer, Einhard Bezzel & Wolfgang Fiedler : The compendium of birds in Central Europe - Nonpasseriformes - non-singing birds. Aula, Wiebelsheim 2005, ISBN 3-89104-647-2 .
Norbert Schäffer : Habitat choice and partnership system of spotted rail Porzana porzana and Corn Crake Crex crex. In: Ecology of Birds. No. 21, 1999, ISSN 0173-0711 (dissertation, University of Würzburg 1997).
Kees Koffijberg, Norbert Schäffer, et al .: International Single Species Action Plan for the Conservation of the Corncrake. (CMS Technical Series No. 14 / AEWA Technical Series No. 9). June 2006 ( pdf , cms.int).
Helmut Nauendorf, Wolfgang Wetzel (eds.): Upright defense of the area: 25 and 1 year of the Heckschnärre, Nürtingen-Frickenhausen 2010, ISBN 978-3-928812-54-2 .

Individual evidence

↑ RL Potapov, VE Flint (ed.): Handbook of the birds of the Soviet Union. Volume 4: Galliformes, Gruiformes. Aula Verlag, Wiesbaden 1989, ISBN 3-89104-417-8 , p. 265

↑ ^a ^b Glutz v. Blotzheim, p. 447f, s. literature

↑ Glutz v. Blotzheim, p. 463, s. literature

Jump up ↑ Norris (1947), Bosch (1952 and 1955), Braaksma (1962) in Glutz v. Blotzheim, p. 463f, s. literature

^ Archer & Godman (1937) in Glutz v. Blotzheim, p. 464, p. literature

↑ Christoph Grüneberg, Hans-Günther Bauer, Heiko Haupt, Ommo Hüppop, Torsten Ryslavy, Peter Südbeck: Red List of Germany's Breeding Birds , 5 version . In: German Council for Bird Protection (Hrsg.): Reports on bird protection . tape 52 , November 30, 2015.

^ Brian Huntley, Rhys E. Green, Yvonne C. Collingham, Stephen G. Willis: A Climatic Atlas of European Breeding Birds. Durham University, The RSPB and Lynx Editions, Barcelona 2007, ISBN 978-84-96553-14-9 , p. 155.