Corncrake, Landrail
The Corn crake (Crex crex) is a medium-sized ground-dwelling bird that is found breeds in Europe and Asia and migrates to Africa to spend winter. Despite its elusive nature, the loud call has ensured the Corn crake has been noted in the literature and garnered a range of local and dialect names.
The adult male Corn crake has the crown of its head and all of its upperparts brown-black in color, streaked with buff or grey. The wing coverts are a distinctive chestnut color with some white bars. The face, neck, and breast are blue-grey, apart from a pale brown streak from the base of the bill to behind the eye, the belly is white, and the flanks, and undertail are barred with chestnut and white. The strong bill is flesh-colored, the iris is pale brown, and the legs and feet are pale grey. Compared to the male, the female has warmer-toned upperparts and a narrower duller eye streak. Outside the breeding season, the upperparts of both sexes become darker and the underparts less grey. The juvenile is like the adult in appearance but has a yellow tone to its upperparts, and the grey of the underparts is replaced with buff-brown. The chicks have black down, as with all rails. All populations show great individual variation in coloring, and the birds gradually become paler and greyer towards the east of the range. Adults undergo a complete molt after breeding, which is normally finished by late August or early September, before migration to southeastern Africa. There is a pre-breeding partial molt prior to the return from Africa, mainly involving the plumage of the head, body, and tail. Young birds have a head and body molt about five weeks after hatching.
Corn crakes breed from Ireland east through Europe to central Siberia. There is also a sizable population in western China, but these birds nest only rarely in northern Spain and in Turkey. Corn crakes winter mainly in Africa, from the Democratic Republic of the Congo and central Tanzania south to eastern South Africa. They may occasionally winter in North Africa and to the west and north of their core area in southeast Africa. Most of the South African population occurs in KwaZulu-Natal and the former Transvaal Province. Corn crakes usually inhabit lowlands but breed at high altitudes. When breeding they are mainly found in cool moist grassland, particularly moist traditional farmland. They can also be found in other treeless grasslands in mountains or taiga, on coasts, or where created by fire. They may also occur in moister areas like wetland edges, but very wet habitats and open areas and those with vegetation more than 50 cm (20 in) tall, or too dense to walk through are usually avoided. On their wintering grounds in Africa, Corn crakes occupy dry grassland and savanna habitats, in vegetation 30-200 cm (0.98-6.56 ft) tall, including seasonally burnt areas and occasionally sedges or reed beds. They are also found on fallow and abandoned fields, uncut grass on airfields, and the edges of crops.
Corn crakes are solitary on the wintering grounds, where each bird occupies a territory of about 4.2-4.9 ha (10-12 acres) at one time. During migration, they may form flocks of up to 40 birds and sometimes associate with Common quails. They migrate at night and during the day flocks may gather up to hundreds of birds at favored resting sites. Corn crakes are most active early and late in the day, after heavy rain, and during light rain. They walk with a high-stepping action and can run swiftly through the grass with their body held horizontally and laterally flattened. They will swim if needed. Corn crakes forage on the ground in cover; they may search leaf litter with their bill, and run in pursuit of active prey. When flushed by a dog, they will fly less than 50 m (160 ft), frequently landing behind a bush or thicket, and then crouch on landing. If disturbed in the open, Corn crakes will often run in a crouch for a short distance, then stand upright to watch the intruder. When captured they may feign death, recovering at once if they see a way out. Corn crakes communicate using various calls. On the breeding grounds, the males' advertising call is a loud, repetitive, grating 'krek krek' normally delivered from a low perch. It can be heard from 1.5 km (0.93 mi) away and serves to establish the breeding territory, attract females, and challenge intruding males. The females may give a call that is similar to that of the males. Females also have a high-pitched 'cheep' call, and a 'oo-oo-oo' sound to call the chick. The chicks make a quiet 'peeick-peeick' contact call, and a 'chirp' used to beg for food. In Africa, Corn crakes are usually silent.
Corn crakes have an omnivorous diet but mainly feed on invertebrates, including earthworms, slugs and snails, spiders, beetles, dragonflies, grasshoppers, and other insects. They will also eat small frogs and mammals, and plant material including grass seed and cereal grain.
Corn crakes were thought to be monogamous, but some males may be polygynous; they have a shifting home range, and mate with two or more females, moving on when laying is almost complete. The male's territory can vary from 3 to 51 ha (7.4 to 126 acres), while the female has a much smaller range, averaging only 5.5 ha (14 acres). A male will challenge an intruder by calling with his wings drooped and his head pointing forward. Usually, the stranger moves off; if it stays, the two birds square up with heads and necks raised and the wings touching the ground. They then run around giving the growling call and lunging at each other. The male performs a brief courtship display and may offer food to a female. The nest is usually located in grassland, sometimes in safer sites along a hedge, near an isolated tree or bush, or in overgrown vegetation. The nest is built in a scrape or hollow in the ground. It is made of woven coarse dry grass and other plants, and lined with finer grasses. The female lays a clutch of 8-12 eggs and incubates them alone for about 19-20 days. Precocial chicks leave the nest within a day or two. They are fed by the female for 3-4 days but can find their own food thereafter. They fledge after 34-38 days and when fully grown they may fly with the parents up to 6.4 km (4 mi) to visit supplementary feeding areas. The second brood is started about 42 days after the first, and the incubation period is slightly shorter at 16-18 days. The grown young may stay with the female until departure for Africa.
The breeding Corn crake population had begun to decline in the 19th century, but the process gained pace after World War II. The main cause of the steep decline in much of Europe is the loss of nests and chicks from early mowing before breeding is completed. Loss of habitat is the other major threat to Corn crakes mainly due to agricultural expansion, repeated cut of grass, and degradation. More localized threats include floods in spring and disturbance by roads or wind farms. More significant than direct hunting is the loss of many birds, up to 14,000 a year, in Egypt, where migrating birds are captured in nets set for the quail with which they often migrate.
According to the IUCN Red List, the total Corn crake population size is estimated at 3,600,000-6,700,000 mature individuals. The European population consists of 1,290,000-2,120,000 breeding males, which equates to 2,590,000-4,240,000 mature individuals (including 1-1.5 million pairs in European Russia). A further 515,000-1,240,000 pairs are estimated for Asiatic Russia. Currently, this species is classified as Least Concern (LC) on the IUCn Red List and its numbers today are stable.
