The red-throated loon or red-throated diver is a migratory aquatic bird found in the northern hemisphere. The most widely distributed member of the loon or diver family, it breeds primarily in Arctic regions, and winters in northern coastal waters. Ranging from 55 to 67 centimetres in length, the red-throated loon is the smallest and lightest of the world's loons. In winter, it is a nondescript bird, greyish above fading to white below. During the breeding season, it acquires the distinctive reddish throat patch which is the basis for its common name. Fish form the bulk of its diet, though amphibians, invertebrates, and plant material are sometimes eaten as well. A monogamous species, red-throated loons form long-term pair bonds. Both members of the pair help to build the nest, incubate the eggs, and feed the hatched young.
Region
Arctic and subarctic of North America and Eurasia
Typical Environment
Breeds on tundra lakes, bogs, and moorland pools, often close to the coast. Prefers small, shallow freshwater ponds for nesting with open sightlines and minimal disturbance. In winter it moves to marine environments, favoring sheltered coastal waters, bays, and estuaries. Regularly commutes between inland breeding sites and coastal feeding areas, sometimes over many kilometers.
Altitude Range
Sea level to 1000 m
Climate Zone
Polar
Ease of Keeping
Beginner friendly: 1/5
The red-throated loon (red-throated diver) is the smallest and most widely distributed loon, breeding across Arctic and subarctic regions and wintering along northern coasts. It often nests beside very small inland pools yet commutes to the sea to feed. Pairs are typically monogamous and share nesting and chick-rearing duties. Its slender, slightly upturned bill and reddish throat patch in breeding plumage are key identification features.
The red-throated loon breeds primarily in coastal tundra, often on very small lakes.
Among the loons, the red-throated loon is exceptional in its ability to take off from very small bodies of water.
Once they are 3–4 days old, the young are fed fish—which can be quite large compared to the size of the chick.
Eggs, Collection Museum Wiesbaden
Chicks are competent swimmers, able to accompany their parents soon after hatching.
Juveniles have darker necks and fewer speckles on their backs than adults do.
Temperament
solitary and territorial
Flight Pattern
strong flier with rapid, direct wingbeats low over water
Social Behavior
Forms long-term monogamous pairs that defend small territories around breeding ponds. Both sexes build the nest near the water’s edge, incubate 1–2 eggs, and feed the chicks. Small groups may gather on coastal waters outside the breeding season, but large flocks are uncommon.
Migratory Pattern
Seasonal migrant
Song Description
A haunting series of wails, cackles, and croaks that carry over long distances across tundra lakes. Calls intensify during courtship and territorial displays and are quieter and less frequent in winter.
