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 Iceland. Small numbers breed on Svalbard and sporadically elsewhere in Arctic Eurasia. Common loons winter on both coasts of the US as far south as Mexico, and on the Atlantic coast of Europe.
Region
Northern North America and North Atlantic
Typical Environment
Breeds on large, clear freshwater lakes across Canada, Alaska, the northern United States, and parts of Greenland and Iceland. Winters mainly along the Atlantic and Pacific coasts of North America and locally on the Atlantic coast of Europe. Prefers lakes with abundant fish, quiet shorelines, and small islands or sheltered coves for nesting. Uses large reservoirs and big rivers during migration. Avoids heavily disturbed shorelines and needs open water to take off.
Altitude Range
Sea level to 2000 m
Climate Zone
Temperate
Ease of Keeping
Beginner friendly: 1/5
The common loon is famed for its haunting yodels, wails, and tremolos that carry far across northern lakes. Its feet are set far back on the body, making it an exceptional diver but awkward on land. It requires a long watery runway to take off, skimming the surface before lifting. Red eyes in breeding season may enhance underwater vision while pursuing fish.
Common loon stretching
Juvenile off Mcgee Island, Maine
In Bodega Bay, California
Foraging
On a waterside nest in Maine
Egg
Taxidermied common loon at the Milwaukee Public Museum
Cassell's book of birds, ca 1875
Temperament
solitary and territorial
Flight Pattern
strong flier with deep wingbeats; requires a long water run to take off
Social Behavior
Pairs defend breeding territories vigorously and nest on shorelines or small islets close to deep water. Nests are shallow mounds of vegetation; both parents incubate and rear the chicks. Chicks may ride on parents’ backs in the first weeks after hatching.
Migratory Pattern
Seasonal migrant
Song Description
Vocal repertoire includes eerie wails, yodels, and laughing tremolos that travel long distances over water. Calls are used for mate contact, territorial defense, and signaling alarm.
