Corn Crake
Crex crex
Description 5
The corn crake is a medium-sized rail, 27–30 cm (11–12 in) long with a wingspan of 42–53 cm (17–21 in). Males weigh 165 g (5.8 oz) on average and females 145 g (5.1 oz). The adult male has the crown of its head and all of its upperparts brown-black in colour, streaked with buff or grey. The wing coverts are a distinctive chestnut colour 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-coloured, 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. While there are no subspecies, all populations show great individual variation in colouring, and the birds gradually become paler and greyer towards the east of the range. Adults undergo a complete moult after breeding, which is normally finished by late August or early September, before migration to south eastern Africa. There is a pre-breeding partial moult prior to the return from Africa, mainly involving the plumage of the head, body and tail. Young birds have a head and body moult about five weeks after hatching.
The corn crake is sympatric with the African crake on the wintering grounds, but can be distinguished by its larger size, paler upperparts, tawny upperwing and different underparts pattern. In flight, it has longer, less rounded wings, and shallower wingbeats than its African relative, and shows a white leading edge to the inner wing. In both the breeding and wintering ranges it is unlikely to be confused with any other rails, since sympatric species are smaller, with white markings on the upperparts, different underparts patterns and shorter bills. A flying corn crake can resemble a gamebird, but its chestnut wing pattern and dangling legs are diagnostic.
On the breeding grounds, the male corn crake's advertising call is a loud, repetitive, grating krek krek normally delivered from a low perch with the bird's head and neck almost vertical and its bill wide open. The call can be heard from 1.5 km (0.93 mi) away, and serves to establish the breeding territory, attract females, and challenge intruding males. Slight differences in vocalisations mean that individual males can be distinguished by their calls. Early in the season, the call is given almost continuously at night, and often during the day, too. It may be repeated more than 20,000 times a night, with a peak between midnight and 3 am. The call has evolved to make a singing male's location clear, as this species hides in vegetation. The frequency of calling reduces after a few weeks but may intensify again near the end of the laying period before falling away towards the end of the breeding season. To attract males, mechanical imitations of their call can be produced by rubbing two pieces of wood or ribs, one of them with notches, or by flicking a credit card against a comb or zip-fastener. The male also has a growling call, given with the bill shut and used during aggressive interactions.
The female corn crake may give a call that is similar to that of the male; it also has a distinctive barking sound, similar in rhythm to the main call but without the grating quality. The female also has 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. Because of the difficulty in seeing this species, it is usually censused by counting males calling between 11 pm and 3 am; the birds do not move much at night, whereas they may wander up to 600 m (660 yd) during the day, which could lead to double-counting if monitored then. Identifying individual males suggests that just counting calling birds underestimates the true count by nearly 30%, and the discrepancy is likely to be greater, since only 80% of males may call at all on a given night. The corn crake is silent in Africa.
Distribution of Crex crex (Photo 11) 6
Yellow : Breeding range
Blue : Wintering range
Sources and Credits
- (c) Aleksandar, some rights reserved (CC BY-SA), uploaded by Aleksandar
- (c) Dale Bohlke, some rights reserved (CC BY-NC), https://www.flickr.com/photos/dale_bohlke/27838353074/
- (c) Klaus Rassinger, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Crex_crex_MWNH_0070.JPG
- (c) Jimfbleak, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Crexcrex.png
- (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Corn_crake
- (c) Aleksandar, some rights reserved (CC BY-SA)
More Info
iNat Map
| Region | Banat, Bačka, Južno Pomoravlje, Kosovo i Metohija, Podrinje i Posavina, Raška, Srem, Timok i Braničevo, Šopluk, Šumadija |
|---|---|
| Color | black, brown, gray, pink, white, yellow |
