Great Northern Loon

The common loon or great northern diver is a large member of the loon, or diver, family of birds. Breeding adults have a plumage that includes a broad black head and neck with a greenish, purplish, or bluish sheen, blackish or blackish-grey upperparts, and pure white underparts except some black on the undertail coverts and vent. Non-breeding adults are brownish with a dark neck and head marked with dark grey-brown.

Their upperparts are dark brownish-grey with an unclear pattern of squares on the shoulders, and the underparts, lower face, chin, and throat are whitish. The sexes look alike, though males are significantly heavier than females. During the breeding season, loons live on lakes and other waterways in Canada, the northern United States, and southern parts of Greenland and...

Common loons are mainly Nearctic, and breed from 48° N to the Arctic Circle, locally south to 40° N and north to 78° N. Deep lakes with warm surface waters, relatively low biological productivity and low turbidity where their fish prey are easy to see are habitats where breeding loons are more successful in raising young. For protection from predators, common loons favour lakes with islands and...