Cape Shoveler

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Cape Shoveler
Cape Shoveler RWD.jpg

Cape Shoveler ( Spatula smithii )

Systematics
Order : Goose birds (Anseriformes)
Family : Duck birds (Anatidae)
Subfamily : Anatinae
Tribe : Swimming ducks (anatini)
Genre : Shoveler ( spatula )
Type : Cape Shoveler
Scientific name
Spatula smithii
( Hartert, E , 1891)

The Cape Shoveler ( Spatula smithii , syn .: Anas smithii ), also known as the South African Shoveler , is a South African duck bird that is counted among the swimming ducks. She is the largest of the shovelers.

Appearance

The Cape Shoveler reaches a body length of 53 centimeters. It swims relatively deep in the water, the beak usually points towards the surface of the water. The males can be identified mainly by their light cream-colored head and the lightened sides of the neck, which are clearly differentiated from the dark, chunky beak and the dark body plumage. Shoulder and scapular plumage are particularly dark and have a pale green sheen. The flank feathers are lined with reddish brown. The females are slightly smaller and have a lighter beak. With them, the body plumage does not contrast so noticeably with the head plumage. In flight, the large beak and the light blue-gray wing covers are also essential distinguishing features. The green wing surface is always bordered white in the male. In the female, this feature is less noticeable and can also be completely absent in some individuals. The females are generally a little darker gray than those of other shovelers. The lower wings are pale brown in both sexes. The male has yellow feet and legs. In the breeding season they are a brilliant yellow-orange. The eyes are yellow. In females, the beak is more dark brown than black. The legs and feet are yellow-brown. The eyes are dark brown. Young ducks resemble the females in their plumage. However, they are a little lighter and their plumage is not as rich in contrast. In male young ducks, the shoulders are already blackish and the large arm covers are white. In the young females, on the other hand, the back plumage is lighter and the large blankets are gray.

The Cape Shoveler shows no seasonal dimorphism . This distinguishes them from African Anas species, in which the males all wear a different color, calm and splendid dress. The moulting pattern of this duck species has not yet been adequately investigated. But they probably change their plumage twice a year.

There is a possibility of confusion with the Eurasian shoveler , which overwintered in the area of ​​distribution of the Cape Shoveler, whose resting dress is very similar to the plumage of the Cape Shoveler young ducks.

Distribution area

The distribution area of ​​the Cape Shoveler is limited to the south of Africa. It extends from the Cape to southwestern Angola, northern Namibia, Botswana and southwest Zimbabwe. It is absent in the north of the Transvaal and in Mozambique. She is a partial puller. Birds ringed in South Africa have been found 1,680 kilometers further north in Namibia. Stray visitors can occasionally be seen in Zambia, Tanzania and Zaire.

The Cape Shoveler is believed to be common in southwest Africa. Population figures have not yet been reliably determined because the nomadic way of life of this duck in the interior of Africa makes it difficult to record the population. The global population is estimated at around 30,000 to 50,000 ducks. There is no evidence that this species of duck is threatened in its population.

Habitat and general behavioral characteristics

The Cape Shoveler is mainly seen in shallow fresh water and in wetlands. It also uses floodplains. It also uses estuaries and brackish water lagoons as well as salt lakes for foraging. On the other hand, it avoids deep and fast flowing waters. The food supply and less the nature of the bank vegetation is decisive for the settlement of a body of water.

Outside of the breeding season, they can often be seen in small groups. Large flocks are rare, although gatherings of up to 600 Cape shovelers have been observed. It finds its food by sifting through the water in shallow bodies of water. Often she swims with her head submerged. It seldom founds. As can often be observed with shovelers, this species of duck often searches for food together with other shovelers. Two to seven Cape Shovelers swim in a circle and pick up aquatic invertebrates and tadpoles. There are different views on the importance of plant-based food. According to ornithologist Janet Kear , vegetable foods play only a minor role in the diet of this species of duck. According to ornithologist Hartmut Kolbe, who also specializes in ducks, seeds and green parts of aquatic plants, especially spawning herbs, make up 30 percent of the diet.

Reproduction

The Cape Shoveler 'courtship repertoire does not differ much from that of other Shovelers. The males often stay close to the females during the breeding season and when they are rearing their young, and defend them vigorously.

Clutches of the Cape Shoveler have been found every month. In some regions, the breeding season is likely triggered by the start of the rainy season. In the Transvaal, the main breeding season falls from July to September. In the southwestern Cape Province, the Cape Shovelers breed mainly in the months of August to December. Outside of this time, only a few, individual clutches are found here.

The nests are usually built in the bank vegetation. The eggs are oval with a smooth surface. The skin is cream-colored and can be tinged with green. The full clutch consists of an average of 9.3 eggs (range 5 to 12 eggs). The female breeds alone. The breeding season is 27 to 28 days. The young are fledged after 56 to 63 days. Presumably only one clutch is raised per year.

Keeping in human care

The Cape Shoveler has a rather inconspicuous plumage compared to many other duck species. Accordingly, it is rarely kept by private breeders or shown in zoos. The British Wildfowl Trust imported this species of duck in 1950 and bred it for the first time in 1952.

supporting documents

Individual evidence

  1. ↑ Kolbe, p. 225
  2. ↑ Kear, p. 553
  3. ↑ Kear, p. 553
  4. ↑ Kolbe, p. 226
  5. ↑ Kear, p. 553
  6. ↑ Kear, p. 554
  7. ↑ Kear, p. 554
  8. ↑ Kear, p. 554
  9. ^ Kear, p. 555
  10. ^ Kear, p. 555
  11. ^ Kear, p. 555
  12. ↑ Kolbe, p. 227

literature

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