Corn Crake Crex crex Scientific name definitions

27–30 cm; male 129–210 (165·5)g, female 138–158 (145)g; wingspan 42–53 cm. Sexes similar, but female has slightly warmer buff upperparts, narrower and duller grey streak over eye , and sometimes less grey on cheeks, neck and breast. Non-breeding plumage similar to breeding , but upperparts more rufous-brown, less grey; male has less grey on side of head, and little or none on neck and breast; female has faint grey tinge in streak over eye, and often none on cheeks, neck and breast. Separable from C. egregia, which is sympatric in wintering areas, by larger size, paler upperparts, chestnut upperwing-coverts, less grey on face, neck and breast, and underparts barred with red-brown and white; easily distinguishable on plumage from other sympatric crakes in breeding and wintering ranges. Immature very like adult but probably has limited barring on upperwing-coverts. Juvenile like adult but has narrower, more buff-yellow-tinged, brown feather fringes on upperparts; less barring on upperwing-coverts; grey of sides of head, foreneck and breast replaced with buff-brown, sometimes with white dots on breast; less contrastingly barred flanks; duller iris; dark grey legs and feet.

W & NW Europe (from British Is) E to NW China and C Siberia. Winters mainly from E DRCongo and S Tanzania S to E South Africa.

Breeding habitat essentially dry to moist meadows and other grasslands , including alpine meadows, marsh fringes and cleared forest areas; prefers dense herbage from head height to c. 50 cm tall. Avoids very marshy areas, standing water, and open ground with rocks, gravel or sand. Locally inhabits fields of cereals, potatoes or fodder plants, especially after breeding, when adults may also move into tall vegetation along ditches, roads and dams. Occupies similar habitats on wintering grounds: predominantly in dry grassland and savanna, often in areas burnt during dry season; in Zambia occurs in dry to moist grass 0·3–2 m high; also frequents rank grass (especially near rivers, sewage ponds and pools), pastures, hay and lucerne fields, fallow fields, neglected cultivation, airfields, and even suburban gardens; in South Africa also in moist to shallowly flooded sedges and reedbeds. On migration, also found in wheatfields and at golf courses. From sea-level up to c. 3000 m.

Almost wholly long-distance migrant, although numerous Dec–Feb records from W Europe, especially in 19th century when breeding population much larger. Main flyways into Africa: W route via Morocco and Algeria; and more important E route via Egypt; few cross Mediterranean between these flyways. Some, probably from E Palearctic, enter Egypt and Sudan via Arabia and Red Sea. Autumn movements Aug–Nov (peak Sept) in Europe; passes through Morocco and Egypt Aug–Oct (mainly Sept); arrives Sudan Sept–Oct and most pass through Kenya Oct–Dec; few recorded S of equator before mid Nov. Most reach C & S Africa late Nov–Dec, and leave late Feb–Apr; return passage more rapid, birds crossing Mediterranean late Mar to mid May; W Palearctic breeding grounds occupied from mid Apr. Twenty-nine young birds radio-tracked in Ireland departed on migration between early Aug and mid Sept, once they had fully grown primaries (1 Donaghy, A.M., Green, R.E. and O’Halloran, J. (2011). Timing of autumn migration of young Corncrakes Crex crex. Ibis. 153: 425–428. Close ). Passage recorded Azerbaijan Sept–Nov and Apr–May. Occasionally winters Mediterranean basin and N Africa. Migrates at night, at low altitude; often strikes lighthouses. Vagrant W to Canary Islands, Azores, Madeira, Iceland, Greenland (c. 20 records), North America (c. 17 records) from Baffin I along Atlantic coast and S to Bermuda, and Fernando de Noronha I, Brazil (2 De Burgos, K. and Olmos, F. (2013). First record of Corncrake Crex crex (Rallidae) for South America. Rev. Bras. Orn. 21(3): 205–208. Close ); S & SE to India/Pakistan (n = 2), Sri Lanka (n = 3), Seychelles, Prince Edward Is (n = 1) (3 Oosthuizen, W.C., Dyer, B.M. and de Bruyn, P.J.N. (2009). Vagrant birds ashore at the Prince Edward Islands, southern Indian Ocean, from 1987 to 2009. Afr. Journal Mar. Sci. 31(3): 445–450. Close ), and Australia (New South Wales and off W Australia); E to Japan (4 Kawakami, K., Suzuki, H., Chiba, H., Suzuki, N. and Horikoshi, K. (2014). [A record of the Corncrake Crex crex on Chichijima Island in the Ogasawara Islands, Japan]. Japanese Journal of Ornithology. 63: 343–345. In Japanese with English summary. Close ); New Zealand record not accepted; in Africa very rare or vagrant to Libya (n = 2), W Mauritania (n = 2), Mali, SW Niger, Chad (n = 2), Nigeria (n = 4), W Somalia (n = 4), Ivory Coast, Ghana, Cameroon, Gabon (n = 3), Congo (n = 3), Angola (n = 2), W Namibia (n = 1) and W Cape (n = 1). High degree of vagrancy indicative of dispersive ability and of readiness with which birds are blown off course by opposing winds.

Earthworms, molluscs, Isopoda, Diplopoda, Arachnida and insects (including Coleoptera, Diptera, Dermaptera, Orthoptera, Odonata, Dictyoptera and Hymenoptera); also small frogs, small mammals and birds (in captivity), green parts of plants, and seeds (especially grasses and grain). Diet similar in wintering areas; in South Africa takes many ants, termites and dung beetles (Scarabaeinae). In wintering areas normally forages within cover, occasionally on open grassy tracks or dirt roads; takes food from ground, low-growing plants and interior of grass tussocks; shifts and probes litter with bill; runs to catch active prey. Most active at dawn and dusk, after rain and during drizzle.

Advertising call of male a monotonous, rasping double call “krek-krek” ; calls from ground or low perch; early in breeding season may call for hours, both day and night. Male also has “growling-mew” call, like grunting squeal of small pigs, used when aggressive and in sexual display. Also various grunts, whistles, cheeps, clicks and quacking notes.

Season Apr–Aug. Monogamous pair-bond of seasonal duration formerly assumed, but serial polygyny regularly occurs, males occupying shifting and overlapping home ranges, and mating with two or more females, remaining with a female only until second half of laying period. By means of acoustic identification of individual males it has been found that in C Europe 50% of males change territories during the breeding season (5 Budka, M., Wojas, L. and Osiejuk, T.S. (2015). Is it possible to acoustically identify individuals within a population? Journal of Ornithology. 156(2): 481–488. Close ). Nest-site in grassland; sometimes in safer sites along hedgerows, near isolated trees, or in bushy or weedgrown areas. Nest on ground, in dense continuous vegetation or in tussock; sometimes only a scrape but usually shallow cup of grass, weeds and brambles, lined with dead leaves; often with surrounding stems pulled over top in loose canopy; average external diameter 12–15 cm; depth 3–4 cm; probably built by female alone. Usually 8–12 eggs (6–14), laid at daily intervals; clutches of up to 19 by two females; incubation 16–19 days, by female alone; hatching synchronous; chick has sooty brown-black down, tinged rufous-brown on upperparts, grey-brown iris, pale pink bill (soon becoming black-brown), and black legs and feet; chicks precocial, leave nest soon after hatching; cared for by female alone, sometimes by two adults (unclear if second is male or female); self-feeding after 3–4 days; independent at fledging or earlier; fledging 34–38 days, when capable of flight; post-juvenile moult then begins and is completed after c. 1 month. Age of first breeding one year. 1–2 broods, in W Europe two broods normal, first hatching mid Jun, second in late Jul; replacements laid after egg loss.

Not globally threatened (Least Concern). Previously considered Vulnerable. Although apparently still common and widespread in parts of range, there is clear evidence of very steep long-term population decline, c. 50% over 20 years, detected in Europe , Russia and Africa; this decline continues and status critical in some W European countries. In breeding areas, drainage of sites, agricultural intensification and changes in grassland management are main causes of habitat loss and of heavy losses of breeding birds, eggs and young. Does not appear to be threatened on African wintering grounds, where grassland habitats may be increasing as woods are felled and some agricultural areas no longer farmed, although grassland habitats suffering locally as result of overgrazing and cultivation. Conservation action includes: establishing reserves in key breeding areas; management to protect nests, adults and young from destruction when cutting meadows for hay or silage; supporting traditional land management practices which benefit species; encouraging continued production of hay; investigating mortality on migration, and seeking ways to reduce such mortality. Integrated national and international conservation approach required. In Britain, numbers have recently shown substantial increases in areas where conservation management measures have been implemented successfully; from a low point in 1993, with only 480 singing birds recorded, the population increased to 1316 singing birds in 2014 (6 Wotton, S.R., Eaton, M., Ewing, S.R. and Green, R.E. (2015). The increase in the Corncrake Crex crex population of the United Kingdom has slowed. Bird Study. 62(4): 486–497. Close ); in the core areas of Scotland there was an average annual rate of increase of 20% between 2001 and 2004, when numbers rose from 596 to 1036 singing males.