Black-throated Diver, known in North America as the Arctic Loon (Gavia arctica), is a medium-sized member of the loon or diver family.
It breeds in Eurasia and occasionally in western Alaska and winters at sea or on large lakes over a much wider range.
Breeding adults are 63 cm to 75 cm in length with a 100 cm to 122 cm wingspan. They are like a smaller, sleeker version of the Great Northern Diver. They have a grey head, black throat, white underparts and checkered black-and-white mantle. Non-breeding plumage is drabber with a white chin and neck. 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 yodeling high-pitched wail.