Red-throated Diver

Gavia stellata

SIZE AND DESCRIPTION

60cm. Distinctive breeding plumage includes a brick-red throat, and a grey head and neck. At other times mainly grey-brown above, with white on the face that extends to above the eye. Slender upturned bill; swims with head mostly tilted upwards.

VOICE

Song an eerie wailing, heard in breeding areas. Flight call a goose-like ‘ak ak’.

HABITAT

Breeds on lakes in northern Europe, including Scotland, and winters on coasts and large inland lakes.

FOOD AND HABITS

Primarily a fish-eater; may also feed on molluscs, crustaceans, frogs and plant material. Spears prey underwater, diving to 2–9m in depth. Nest is always close to water.

Black-throated Diver

Gavia arctica

SIZE AND DESCRIPTION

70cm. Intermediate between Red-throated and Great Northern Divers in size, bill size and bulk. In summer has smooth grey head, black throat, striped necksides and chequered back. In winter dull blackish-grey above, white below. Holds head level.

VOICE

Breeding pairs give loud wailing song. Silent in winter.

HABITAT

Breeds in northern Europe (in Britain very rare, north-west Scotland only), moves south in winter. Nests on islands in undisturbed lochs. In winter at sea and on deep coastal lakes and gravel pits. Occurs along all coasts in winter but is scarce.

FOOD AND HABITS

Feeds on fish, makes long deep dives. Usually solitary or small flocks.

Great Northern Diver

Gavia immer

SIZE AND DESCRIPTION

80cm. Largest diver, with bulbous forehead and heavy, dagger-like bill. In breeding plumage has black head with striped white neck patches, body dark with white chequering on back, bill black. In winter dark grey above, whitish below, bill mid-grey.

VOICE

Unlikely to be heard in Britain. Courting pairs have a wailing song.

HABITAT

High Arctic breeder, moving south to north-west European coasts in winter. At sea in sheltered bays, harbours and estuaries, sometimes reservoirs and lakes. Occurs on all coasts, some oversummer in far north-west.

FOOD AND HABITS

Dives for fish, swims buoyantly with level head, often rolls to preen. May form small groups.