Greater Scaup
Scaup ♂ ( Aythya marila )
The Scaup ( Aythya marila ) is a duck of the genus group of diving ducks in the two subspecies A. m. marila and A. m. mariloides occurs. It is nearly circumpolar represented in the coniferous forest zone and partly in the subarctic shrub tundra and thus the northern counterpart to the Old World and the New World Tufted Duck Lesser Scaup.
In Central Europe, the scaup only a sporadic or local breeding bird and summer visitor. It is much more common than watching through puller and winter visitor in northern central Europe. In the interior it is only locally or sporadically during this time before.
- 7.1 Literature
- 7.2 External links
- 7.3 Notes and references
Features
Characteristics of adult Scaup
Scaup are medium-sized diving ducks. You can reach mature body length 40-51 inches. They weigh almost 1.2 kg on average.
Scaup drake Tufted drakes are similar, but do not have a Crest and a gray back. The head plumage shines light green. In some individuals this shimmer can act even purple. The division of the body Coloration - black neck and breast black, white pages and darker tail - similar to the number of pension. The most striking difference from the Tufted Duck is at the front of bright silver-gray colored back. Towards the tail, he becomes increasingly dark gray. The beak is of a bright lead gray. In plumage the male resembles the female largely.
The female is brown and has a very broad white ring around the beak. It resembles in his entire body dress the female of the Tufted Duck. The most reliable distinguishing feature of the Tufted Duck is a white band surrounding the beak root. It is, however, designed in some individuals only as a narrow white hem and occurs in a similar form to narrow even in some Tufted females. In flight, a broad white wing stripe is visible. Scaup are only very rarely seen on land.
The Mauser course is similar to the Tufted Duck. Change The adult females about their body plumage in March. The moulting of wings feathers takes place in the middle of summer or in late summer. The tail feathers are moulted in the period April to September. A partial change of body plumage takes place in August to November. In the male, the Mauser runs later. The change in the plumage begins in late May and usually ends in early July. The wings feathers are shed almost simultaneously, so that they are unable to fly until September for about three to four weeks during the period June.
The voice of the Scaup is heard almost only for mating season. The male calls at this time a very quiet and nasal weiar wik - wik - or faster wiu. To the sounds during the mating season also includes a soft, cooing kuku.
Characteristics of chicks and young birds
Similar to the Tufted Duck and chicks of scaup are predominantly black brown. Some chick is yellow-brown stains found on the wings and the body sides. The breast and belly are creamy white to yellowish. The upper breast is maroon. The throat is also yellow. In the face, they have a diffuse, dark eyes reins.
In newly hatched chicks, the iris is blue-gray. The upper mandible is black-brown with a brown nail. The lower mandible is flesh colored. The legs, feet and webbed feet are dark gray. In juvenile Scaup the iris changes its color to a yellow. This color change is completed just before the ducklings fledge. The beak is gray-blue at this time. Young birds have a plumage that is largely similar to the females. For them, the white ring at the base bill, however, is always formed only small, also the cheeks, the neck, and front sides of the neck are paler with them. The full plumage of adult Scaup show the young birds until the second year of life.
Possible confusion with other ducks birds
The Scaup has a high similarity with the Tufted Duck and the North American Lesser Scaup. The Tufted Duck is smaller in physique less bulky and has a more rounded back. In a floating mountain duck back against it is mostly flat. Tufted ducks are also in the water higher. A key distinguishing feature is the black back of the tufted duck, but this is not always reliably detect in field observations.
Especially great is the confusion between Scaup and Lesser Scaup, as these species have an almost identical body plumage. The breeding range of these two species overlap in Alaska and northern Canada. They also use similar wintering areas on the coast of North America. Among the distinguishing features heard that the fine dark penciling is a little more intense in the Lesser Scaup, so that her back plumage acts overall slightly darker. Their flanks are also gray. The big problem, sure to distinguish these two species, especially complicates the specification of inventory figures for this Article
Dissemination
Scaup are widespread circumpolar north. The breeding areas of the subspecies A. m. marila extending from Scandinavia to the Lena in Siberia. The rest of Siberia and North America are of the slightly smaller subspecies A. m. mariloides populated. The closed breeding area extends from Iceland about the islands and the far north of Scotland to Scandinavia, Norway, Finland and Lapland. From Murmansk and the White Sea coast, the breeding range extends into northern Siberia. Scaup also nest on the Sakhalin Peninsula.
In rare cases one finds breeds in Central Europe, for example in Schleswig -Holstein, in the U.S. at least until after places Ville, Minnesota. There are four animals have been observed on April 12, 1948, as they had destroyed seven leopard frogs.
For the wintering Scaup leave their breeding territories. A few Scaup wintering in south-west Iceland and in southern Alaska. However, the rest of the population spends the winter in the milder the east and west coasts. Thus, among the major European wintering sites of the southwestern Baltic Sea, the North Sea coast, the coastal waters of southern Norway, the UK and Ireland, and the north-western France. Breeding birds from Siberia overcomers in part to the northern and western coast of the Caspian Schwarmeergebietes and in the sink. The Scaup hold then preferably in shallow straits or bays. The main criterion for the selection of the winter quarter is a sufficient supply of food. So overwinter in the Firth of Forth many Scaup, as there are numerous mussels here. The North American populations wintering on the coast of the Pacific and the Atlantic, and on the Mississippi and Missouri. In Asia, wintering areas found on the coasts of Korea and China, and Taiwan. Approximately 170,000 Scaup can be found in winter on the coasts of Japan.
Overhauling Scaup can be observed in Central Europe from September. The withdrawal from winter quarters starts in mild winters as early as February, otherwise mid-March. In the Baltic Sea area is the highlight of the retreat in April. At their northern breeding grounds meet tufted only one from the middle of May.
Habitat and behavior
During the summer Scaup live in lakes and ponds in the tundra and forest tundra. To their area of distribution includes subalpine waters and fells. The winter months spend the animals along the sea coasts of the temperate latitudes. She pulls against protected secluded sections of the coast and often stayed in estuaries. There, where they wintered inland, it attracts standing water prior to flowing waters.
Scaup breeding on the water on the floor. The breeding begins in May, ending in July, and is depending on the subspecies 24-25 or 28 days. The young fledge after about 50 days.
Food
Scaup feed mainly from animal food, especially mussels, snails and frogs, to a lesser extent also by seeds, sprouts and leaves of aquatic plants. Plant food is consumed especially in spring and summer. Seeds play a greater role in their diet as leaves and sprouts. Dunenjunge eat mostly animal diet you catch insects with its beak or take them from the water surface.
Reproduction
Scaup begin their courtship already in winter quarters. The culmination of the courtship is only achieved when the animals are returned to the breeding area. There takes place the pair formation for most of the population. The return to the breeding grounds from mid -April. The majority of the population, however, applies only in early May there.
Tufted preferred breed on open waters in marsh or tundra landscapes. The nests are built near the shore and are usually in the sedges and rushes stocks. Scaup prefer to breed on islands and then also nest colony -like dense. In some regions of their breeding range to find their nests in gulls and Seeschwalbenkolonien. Scaup annually attract only a scrim large.
A single nest consists generally of six to nine eggs. They are light brown in color and olivgrauer to long oval with a size of 63.2 x 43.5 mm. The females begin to lay eggs in the southern breeding areas from late May. Higher in the north is the breeding begins in early June. It broods alone the female. The drakes remain until the second half of breeding in the vicinity of the nest and the female and spend the time in which it leaves the nest to receive food, with the females. Dunenjungen the hatch in a time period of 26 to 28 days. They fledge after five to six weeks.
Stock
In north-west Europe winter a total of about 310,000 Scaup. The wintering population on the Black Sea, the Caspian Sea and the Mediterranean is estimated to be about 200,000 Scaup. The North American population, which is the Lesser Scaup is very difficult to determine precisely because of the possibility of confusion, is assumed to be about 750,000 Scaup. There are also around 200,000 and 400,000 Scaup, which have their breeding grounds in the north of East Asia.
Long-term changes in inventory are barely visible in the European breeding populations. To greater losses occur due to drowning in fishing nets, a problem that mainly occurs in the IJsselmeer. Oil spills pose for this type another hazard and the concentration of this kind on a few large resting and wintering places is also critical to see, because it is at these locations to often not legally protected sites and these are breeds of ducks is hunted.