UKBirds

Black-Throated Diver

Gavia arctica

The Black-throated Loon (Gavia arctica) is a migratory aquatic bird found in the northern hemisphere. The species is known as an Arctic Loon in North America and the Black-throated Diver in Eurasia, its current name is a compromise proposed by the International Ornithological Committee.

Breeding adults are 58 to 77 cm (23 to 30 in) in length with a 100 to 130 cm (39 to 51 in) wingspan, shaped like a smaller, sleeker version of the Great Northern Diver. Body mass is reportedly from 2-3.4 kg (4.4-7.5 lb). They have a grey head, black throat, white underparts and chequered black-and-white mantle. Non-breeding plumage is drabber with the chin and foreneck white. Its bill is grey or whitish and dagger-shaped. In all plumages a white flank patch distinguishes this species from all other divers including the otherwise almost identical Pacific Diver.