American coot

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American coot
American coot head portrait (Fulica americana)

American coot head portrait ( Fulica americana )

Systematics
Class : Birds (aves)
Order : Crane birds (Gruiformes)
Family : Rallen (Rallidae)
Genre : Coots ( Fulica )
Type : American coot
Scientific name
Fulica americana
Gmelin , 1789
American coot

The American coot ( Fulica americana ) is a medium sized type from the family of Rails that in large parts of North America from the Great Slave Lake south, in Central America and scattered in the northern Andes occurs. It is quite closely related to the Eurasian coot and is one of the most common waterfowl in North America. The largest populations of this species are found in the Prairie Pothole region of southwestern Canada and the north-central United States .

description

The American coot is similar to the Eurasian coot. It is a 32–43 cm large, rounded rail, which is perfectly adapted to swimming, with strong legs, long toes and wide swimming flaps. The weight is 427–848 g. The sexes do not differ except for a slight difference in size.

In adult birds, the head is velvety black, the top is slate gray, the bottom is brownish gray. The lateral under tail coverts are white. On the front back there is sometimes an olive tint, on the chest in the freshly molten plumage, fine white lace hems are visible. The wings have white tips that form a white border on the hind wing. The white beak shows a dark subterminal band and merges into a white forehead shield, which has a red-brown callus at the top. In some birds, this may be absent or may have a yellowish color, and the horn shield may be prominent during the breeding season. The beak and the forehead shield can show a reddish or yellowish green tint. The transition between the beak and the horn shield is only slightly indented - in other species of the genus it is clearly shaped differently. The iris is dark red to red-brown. The color of the legs varies between green-yellow and orange-yellow.

Birds in youthful dress are gray-brown on top. The underside is much lighter. The upper part of the head is quite dark in color and stands out from the whitish throat, the color of which ends in the gray of the chest and stomach. The lateral under tail-coverts are white, the feet and legs are gray-green.

Downy young are predominantly black with fiery red to dark orange downy plumage on the forehead, chin and reins and an intense red beak. The bare top of the head is red and shows blue discolored areas over the eyes.

voice

The vocalizations of the American coot are quite diverse, the species is very happy to shout, which is undoubtedly due to the fact that the birds can best communicate with each other in the confusing habitat dominated by bank plants. The calls of males and females are different.

The male's contact call is a high, clear puck , while the female's call is a deep , nasal pank . As an alarm call, the male gives a puhlk , the female puhnk . A plaintive, crowing, somewhat peacock-like puk-kuwah can be heard as a cry of excitement when defending the territory , and a simpler kuwah can be heard from the female . The warning calls that are given to potential intruders are very variable. A quickly lined up puk-ut is heard from the male, a more nasal punk-unk from the female . The male's threatening cry is a loud puhk-kuh-kuk , that of the female a hollow crowing kau-pow . The male's courtship call is a cough-like sound that can increase to a sharp pörk or körk when the female is pursued . If this is not ready for pairing, it answers with a cackling teck-teck . On the other hand, if it tries to lure the male, it will hear a nasal punt or a sharp put-put .

distribution

The breeding distribution of the American coot covers large parts of North America. In the high arctic areas, in most of the southern states and many southern desert regions, however, it is missing. In the northwest of the continent the distribution is concentrated around the Prairie Pothole region , in the northeast in the southern area of ​​the Great Lakes .

In British Columbia , the species only occurs regularly in the south and northwest. To the north, however, scattered deposits extend into Mackenzie . There are two isolated populations in the eastern central part of Alaska near Tetlin and in the southern central part of the Yukon near the Pelly River . In Alberta the distribution extends relatively far to the north, in Saskatchewan and Manitoba up to the level of Reindeer Lake , whereby it is limited in Manitoba to the southwest. In the area of ​​the Great Lakes, the species breeds in the southern part in partially fragmented occurrences eastward up the Saint Lawrence River in southern Québec and southward into southeastern Indiana . There are also isolated occurrences as far as southern central Ontario , to Nova Scotia , in Maine and Massachusetts . Individual breeding records come from many southern states.

In the western half of the USA, the distribution extends south from Canada to the Mexican border and from the Pacific coast to the east of North and South Dakota , Nebraska , Kansas , Oklahoma and Texas . However, the species is absent in the desert areas, and is rare at higher altitudes.

The American coot also breeds in the USA on the Florida peninsula, omitting the southwest, scattered along the coast of the Gulf from Mexico to Louisiana and on the Atlantic coast to North Carolina .

In Mexico , too , the species occurs in most of the country, but it is absent in the middle of Lower California , in the area of ​​the Sierra Madre Occidental , the Sierra Madre del Sur and the Yucatán Peninsula . In Central America, the American coot breeds in southern Guatemala and scattered in southwest Honduras , in El Salvador and in northwest Costa Rica . In the West Indies it occurs as a rare breeding bird in the Bahamas , Cuba , Jamaica and Hispaniola , occasionally also on the Cayman and Virgin Islands .

In South America there is a small island in the Colombian provinces of Cundinamarca and Boyacá .

Geographic variation

Two subspecies are recognized. The birds of North America hardly vary, but an average larger forehead shield was found in the eastern populations. The South American subspecies is larger, has longer toes and tibiotarsi, and a longer forehead shield. While the North American subspecies shows very broad white tips on the inner arm wings, those of the South American birds are smaller or even limited to the inner vane. According to some authors, F. a. columbiana is a transitional form to the Andean coot ( Fulica ardesiaca ). Vocal and ethological features as well as the development of the downy coat and forehead shield, however, indicate a closer relationship with F. a. americana close.

Another subspecies native to the South American Andes, F. a. peruviana Morrison , 1939. According to investigations by Jon Fjeldsås from 1982, however, this population is a subspecies of the Andean coot ( Fulica ardesiaca ), for which he was named F. a. atrura suggests.

The carib coot, once considered a separate species Fulica caribaea , is currently considered to be the color morph of the American coot.

habitat

The American coot breeds in a wide range of inland waterways and wetlands such as lakes, ponds, canals, septic tanks, swamp holes, floodplains, or slow-flowing rivers. A prerequisite are areas that are densely overgrown with marsh or bank plants and have at least littered, free water areas. These requirements must be met at least throughout the breeding season. Periodically flooded wet grassland can therefore also be used as a breeding ground in years with high water levels. Brackish water habitats are also assumed, but waters with a high salt content are not. The optimal habitats are in wetlands and offer a small-scale mosaic of open water areas and dense swamp vegetation. The altitude distribution extends up to 2500 m in some cases, but the species is usually rare in mountainous areas and its occurrence is limited to waters with cattails and pond sill .

nutrition

The American coot feeds primarily on aquatic plants and algae , occasionally also on grasses and other land plants or their seeds. In addition, there is animal food. These include living aquatic invertebrates such as molluscs and crustaceans , insects and their larvae, rarely, vertebrates such as small fish, tadpoles and occasionally carrion.

For the most part, food is sought in shallower water in places where there is a wealth of food such as dense underwater vegetation. It is recorded swimming, submerging or in short dives. Usually it is first brought to the surface and then consumed. Sometimes the American coot can also be found grazing on land. Occasionally it can be observed in kleptoparasitic behavior, for example when it chases off conspecifics or ducks for food.

literature

Web links

Commons : American Coot ( Fulica americana )  - Collection of images, videos, and audio files

Individual evidence

  1. ↑ a b c d Brisbin et al., 2002, sections Distinguishing Characteristics and Appearance , see literature.
  2. ↑ a b Brisbin et al., 2002, section Sounds , see literature.
  3. ↑ a b c d e Brisbin et al., 2002, section Distribution , see literature.
  4. ^ A b Jon Fjeldså : Geographic variation in the Andean Coot Fulica ardesiaca. In: Bulletin of the British Ornithologist's Club. Volume 103, No. 1, 1983, pp. 18-21 ( digitized version ).
  5. ↑ Brisbin et al., 2002, section Systematics , see literature.
  6. ↑ Brisbin et al., 2002, Habitat section , see literature.
  7. ↑ a b Brisbin et al., 2002, section Food Habits , see literature.