African Corncrake

The cowgirl family, to which the African coronet belongs, unites about 150 species of small and medium-sized birds, leading mainly near-water or aquatic life. Most species and the most primitive forms live in the tropics of the Old World , which speaks in favor of the theory of the origin and diversification of the family in this area. However, neither the available paleontological findings , nor molecular data provide an answer to this question ^[2] .

The closest related bird of the African coronel is the (ordinary) coronel ( Crex crex ), nesting in Eurasia and wintering in Africa. The scientific description of the species was made by the German naturalist Wilhelm Peters in 1854, calling it Ortygometra egregia . The position of the species in the genus Ortygometra Leach , 1816 was not accepted, and for a long time many taxonomists attributed the bird to the monotypic genus Crecopsis , identified by the Englishman Richard Sharp in 1893 ^{[3] [4]} . Other authors classified the species as a part of the genus Porzana , emphasizing its outward resemblance to the ash-necked grouse ( Porzana albicollis ) ^[5] . Modern sources, as a rule, consider 2 species as a part of the genus Crex : common and African coriostles ^{[6] [7] [4]} . Both morphologically and phylogenetically , the closest group of birds to them is carnivores ^[8] .

The generic name Crex , whose authorship belongs to Johann Bechstein ^[9] , comes from other Greek. κρέξ , which in the writings of Herodotus , Aristophanes , Aristotle and other authors called a certain long-legged bird. Modern linguists suggest that the name is an imitation of the voice, which can refer to the coronel, turukhtan or stilt ^[10] . The species name egregia comes from the Latin word egregius in the meaning of "excellent, excellent, brilliant" ^[11] .

Appearance

A small stocky bird with short rounded wings and a short conical beak. Noticeably smaller than an ordinary corostel : total length 20-23 cm, wingspan 40–42 cm, weight 92–141 g ^[5] . The feathers of the upper half of the body, including wings and tail, are colored two-tone: the central dark-brown part of the fan is combined with light brownish-olive peaks. The crown is colored the same as the back; the nape and back of the neck are plain light brown; the rest of the head, throat and chest are bluish-gray. From the base of the beak above the eye, a bright strip is developed. The belly and sides are striped black and white.

The rainbow is red, the beak is reddish, legs are gray or light brown. Sexual dimorphism is insignificant, manifests itself in smaller sizes and a duller color of the female, in which the head pattern also looks more blurry. In birds of the first year of life, the top is darker and faded, the development of stripes on the sides and belly is less pronounced, the beak is dark, the rainbow is gray ^[12] . Unlike other birds of open spaces, such as coot and moorhen, the African corpuscle has no white spot on the undertail, which plays the role of a color marker, ^[13] .

Within the range, more or less similar species are the Cape Shepherd ( Rallus caerulescens ) and herd . At the Cape Cowgirl, the beak is noticeably longer and thinner, the fleece has white spots and stripes on the back, the beak is yellow, the legs are greenish, the striped pattern on the belly is less contrasting. The flying rattle along the front edge of the wing has a noticeable white field, which the corostel does not have ^[14] .

Voice

Like other cowherd girls , the African corostel has a rich voice repertoire. The male’s territorial and invocation cry is a series of crackling “rrrr” sounds repeated two or three times per second for several minutes. Most often, it can be heard during daylight hours during the mating season. Sometimes the bird continues to cry with the onset of darkness or begins even before dawn. The current male, as a rule, stands still, straightens and stretches its neck, or screams on the fly or running when pursuing a competitor. Another characteristic sound, this time a loud and sharp “bale,” is made by individuals of both sexes when a danger arises or in a conflict with neighbors. With the beginning of hatching, the birds subside, but after the breakdown of broods, they resume territorial vocalization. Particularly noisy birds behave in areas with a high density of settlements. A man with the help of a decoy can imitate another hoarse sound of a corcostel, which is usually associated with a threat or mating; hearing the sound of decoy, the corncrake approaches a distance of 10 m ^[12] .

The vocalization of the African corostel, in particular, the calling cry of the male, differs markedly from the vocalization of other closely related species — the ordinary corostel , the striped fleece, and the crumb droppings ^[15] . An ordinary crustel wintering in Africa is silent at this time of year ^[16] .

Range

The African coronel is common in sub- Saharan Africa . The northern outskirts of the range roughly corresponds to the line connecting Senegal and Kenya , the southern one passes through the southern African province of KwaZulu-Natal . The bird is absent in arid and semi-arid regions of southern and southwestern Africa, where the annual rainfall does not exceed 300 mm ^[5] , as well as in Madagascar . Partly common, but practically not found in continuous tropical rainforests and semi-deserts with bare soil. Almost the entire South African population - about 8 thousand birds - is concentrated in the province of KwaZulu-Natal and the former province of Transvaal , including the territory of the Kruger National Park and the Ishimangaliso wetland park. Random flights are known in southern Mauritania , southern Niger , Lesotho , in the north and east of the Cape and in the North-Western province of South Africa ^{[12] [17]} , as well as in southern Botswana ^[18] . Occasionally nests on the island of Bioko ( Equatorial Guinea ) ^[19] , was twice seen on the island of Sao Tome and the island of Tenerife (the last case is the only one related to the Western Palaearctic ) ^{[20] [21]} . Fossil findings suggest that earlier in the Holocene , when the climate was more humid, the coronet corpuscle lived in the north of the continent - in the area that the Sahara desert currently occupies ^{[22] [23]} .

Nature of stay

The view is partially migratory. Despite the fact that the African crust is less secretive in comparison with other related species, the nature of its movements is complex and insufficiently studied; for this reason, conclusions about areas where the bird migrates after breeding is largely arbitrary and based on indirect evidence. It is known that the corostel nests in the wet season, and many individuals leave the equatorial belt when in other areas the grass cover reaches an acceptable height for the nest. Mass movement southwards occurs mainly from November to April. When the onset of dry weather burns grass, the direction of migration changes to the opposite. In Equatorial and partly West Africa, most birds live settled or wander for short distances, concentrating in the wettest areas. In Nigeria , Senegal , The Gambia , Côte d'Ivoire and Cameroon, corostels, as a rule, only nest but do not winter ^[12] . They migrate at night in small, up to 8 individuals, groups ^[24] . In South Africa, at least some of the birds remain in the dry season, if the height of the grass allows you to lead a hidden lifestyle ^[18] .

Habitats

It inhabits various landscapes with grassy vegetation from moist meadows along the outskirts of marshes and temporary spills to savannahs, light forests and forest edges. Often found in fields where corn , rice or cotton are grown , on abandoned farms and sugar cane plantations near ponds. It settles in places where the height of the grass varies from 30 cm to 2 m, in most cases up to 1 m.In comparison with an ordinary bark, it prefers more humid areas with not so tall grass, often during the nesting period near bushes or termite thickets. As a rule, it occurs from 0 to 2000 m above sea level, in rare cases and above ^{[5] [12]} . According to one observation in East Africa, the average size of forage territory in the nesting period is about 2.6 hectares and 1.97–2.73 hectares in the rest of the year ^[25] . The highest nesting density was recorded in wet meadows - for example, in the Okavango River Delta in Botswana ^[18] .

Active during the day, especially at dusk, during light rain or after heavy rain. Compared with other closely related species, it is less secretive and often appears in open areas, including on roadsides. Accustomed to the road, the bird usually lets the car reach a distance of one meter, flies closer to a distance of no more than 50 m when approaching. In case of danger, it prefers to move to a wet area or hide behind a bush, clinging to the ground. It flees from dogs by fleeing on the ground, using fast legs and maneuverability, while keeping the body almost horizontal. Often hides in the recesses of the soil under the cover of turf ^[12] .

Territorial throughout the year. In a conflict situation, the male takes a threatening pose - he straightens up, ruffles feathers on his belly and sides, shows signal stripes. The males competing for the territory walk near each other, one of the birds can attack the other. Fights are frequent on the border of the plots, during which the birds jump and try to peck the enemy. Females accompanying males can also conflict with other females, especially if the male is interested in them. Moreover, feathers on the belly of females are not as tousled as males ^[12] .

Nutrition

Of animal feed, it feeds mainly on various invertebrates : earthworms , snails , mollusks , insects at all stages of development. Of the latter, termites , ants , bugs, and grasshoppers predominate. Sometimes it catches small frogs and fish . Plant food is represented by seeds and shoots of herbs.

The forage is extracted both in dense grass and in open space, picking it up from the surface of the earth and plants. Sometimes, in search of food, it immerses the beak in soft or hard soil or pecks prey from the surface of the water. Fast-moving insects chasing ^[12] . From time to time, the bird feeds in the fields of rice, corn or peas, but does not bring significant damage to the crop ^{[26] [27]} . It is kept alone or in small family groups, often in the company of hollows , quail Coturnix adansonii, and common corncrake ^[12] . Chicks are fed animal food. Like many other birds, it swallows small pebbles that help grind food in the stomach ^[28] .

Reproduction

Breeding dates are tied to the rainy season, the beginning of which varies at different latitudes. In the mating season, the female is chased by the male, during which the first cackles, and the second runs with a straightened body and an elongated neck. The female, ready for pairing, stops and lowers its head; the copying process itself lasts a few seconds, but is repeated several times within an hour.

The nest is cup-shaped, shallow, twisted from blades of grass, sometimes has a slightly pronounced canopy. It can be arranged in a lowering of the relief (pit), hidden under a bunch of grass or a small bush. There are nests on bumps in the middle of the spill and even floating ones. The diameter of the nest is about 20 cm, the diameter of the tray is 11–12 cm, the depth of the tray is 2–5 cm. During the day, only one new egg appears in the nest, the complete clutch contains from 3 to 11 eggs, painted in pinkish color ^[29] . The nest is built and laid at the same time: the first egg appears in the nest even when it is a flat grassy platform. Both parents incubate. The first chick is born 14 days after the start of incubation, the rest within the next two days. Chicks of brood type , upon hatching, are covered with black down. Having barely dried, they leave the nest and follow their parents, who take turns feeding and heating them. The ability to fly appears at the age of four or five weeks, when the birds have not yet reached the size of their parents. There is no information on the second clutch for the season ^[12] .

The main natural enemies of the coronel are feline and bird families: leopard ^[30] , serval , domestic cat , black-necked heron , dark song hawk , African hawk eagle ( Aquila spilogastra ) and silver eagle ^[12] . In South Africa, a boomslang venomous snake is hunting for bird chicks ^[31] . When taken off guard, the crustel bounces high before flying away - it is believed that this tactic helps to escape from snakes and ground predators ^[32] .

He suffers from a parasite of some parasites, among which are called ticks from the family Ixodidae ^{[33] [34]} and the poohora Metanalges elongatus ^[35] .

According to experts from BirdLife International and the International Union for Conservation of Nature , the area of ​​the distribution of the African coronel is about 11.7 million km² ^{[36] [37]} . Estimates of the total abundance were not made, however, the bird in most of the range is numerous and stable. In areas where there was a significant change in landscapes due to intensive cattle grazing, plowing of lands, and drainage of swamps, the corostels either disappeared altogether or their population declined sharply. One of such areas is the coastal strip in the South African province of KwaZulu-Natal , which in recent centuries has been heavily urbanized, and part of the land has been used for sugar cane plantations . On the other hand, deforestation with the formation of grassy spaces favorably affects the existence of the species. Corncart meat is edible, and in some countries birds are hunted ^[38] . Despite these negative factors, the corostel in the Red Book has the status of the least risk taxon (LC category) ^[37] .

The African corostel is included in the list of the International (AEWA), the purpose of which is to preserve migratory species ^[39] . In Kenya, the bird is included in the list of species whose position is close to vulnerable ^[40] .

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