Birds in Bulgaria

L 44-54 cm, WS 70-84 cm. Breeds near lakes and rivers in boreal forests (upper coniferous, birch/willow) and close to tundra waters. Migratory, spring migration largely on broad front over land at night, autumn migration diurnal along coasts and over sea. Gregarious, can form very large flocks. Most ♂♂ return S as early as late summer.
IDENTIFICATION: Medium-sized, plump-bodied. Bill fairly small, male with knob at base. Longish tail often exposed when swimming. All-dark plumage without white in wing. Dives usually with small leap, wings kept folded tight to body (cf. p. 64). Wing-flapping punctuated with quick downward thrust of head. Resting flocks usually very dense, more so than with Velvet Scoter, and frequently larger. - Adult male: Whole plumage black. In flight primaries are contrastingly paler, thus wings two-toned, especially in strong light. Centre of bill (culmen) yellow, sometimes visible at longer range in good light, especially viewed head-on. - Adult female: Sootybrown with paler cheeks and dark brown forehead and crown; superficially recalling a swimming female or juvenile Red-crested Pochard, though smaller and darker-bodied, invariably with all-dark bill, and habitat usually different. (A few birds have centre of cheek mottled brown, creating a hint of the ‘two-pale-spots pattern’ typical of Surf Scoter, see below.) - Juvenile: Like adult female but belly paler, brownish-white instead of medium browngrey; plumage somewhat browner, less grey. (Moulting 1st-winter males can also show hint of two pale spots on cheeks just as some females.) Young males attain adult plumage largely in 1st winter but retain pale belly (can look strikingly white in flight!), and by spring wings noticeably faded, brownish. - Variation: NE Siberian and American (ssp. americana, ‘Black Scoter’) males are distinctive, having a large, swollen orange-yellow area on the bill and lacking the black knob at the base; females appear inseparable in the field. A few winter records in W Europe.
VOICE: male has soft piping ‘pjü’, regularly repeated about once per second; heard during display, but most often during spring nights (late Apr/early May) over land in N Europe from NE-bound flocks. Also drawnout ‘pü-ih’ and other short, repeated calls during courtship. Female has a repeated ‘karrr’, similar to many other female diving ducks. Wingbeats produce fine whistling noise.