Yellow-billed Loon

The yellow-billed loon, also known as the white-billed diver, is the largest member of the loon or diver family. Breeding adults have a black head, white underparts and a chequered black-and-white mantle. Non-breeding plumage is drabber with the chin and foreneck white. Its main distinguishing feature is the long straw-yellow bill, which, because the culmen is straight, appears slightly uptilted.