Black-throated Diver, known in North America as Arctic Loon (Gavia arctica) is a medium-sized member of the loon or diver family.
It breeds in Eurasia. It winters at sea or on large lakes over a much wider range.
Breeding adults are like a smaller sleeker version of Great Northern Diver. 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.
This species, like all divers, is a specialist fish-eater, catching its prey underwater. It flies with neck outstretched.
The call is a yodelling high-pitched wailing.