All the ducks described so far had a more or less colorful coat, especially males with mating plumage. Whereas the black mark is completely black. She is a diving duck, belonging to the same family as Aythya ferina. It nests in northern Europe and Asia. Builds nests on islands or on the shores of lakes, in the taiga or in the tundra. In June, the female lays 6 or 9 beige-pinkish eggs. The young hatch after 28-30 days of incubation and the female leads them directly to the water. Ducklings immediately dive in search of molluscs, aquatic insects at various stages of development and small crustaceans. Partly, just like adults, they feed on plants. The black mark winters on the coasts of Europe, from Scandinavia to the Iberian Peninsula.
Brown markers (Melanitta tusca), a close relative of the black markers, nests in the same areas. In contrast to the black mark, the brown mark also appears on the eastern coast of Scandinavia, from where it goes further south. Its wintering grounds are located on the shores of the North Sea and the Baltic Sea, in Great Britain and extends south to the Gulf of Gascon. The same places as the black markers are chosen for nesting. Both species rarely venture inland, where they are protected. They are hunted in northern Europe.
Black marker it is easy to recognize. It can only be confused with coot. Coot, however, has a different beak shape. Its white beak is extended with a white frontal plate, while the upper half of the black marker's beak is orange with a thickening at the base (1). The female is dark brown with a lighter belly and whitish cheeks (2).
Brown markers. The male is dark black, it has a white mirror and a spot of the same color near the eye (3). The female is brown, with a white mirror and an off-white one, barely noticeable, stain on the cheeks (4). In flight, because both males are black, the brown markers can be distinguished by the white mirror on the rear part of the wings. The young are covered with almost black down. Game bird.