Pacific Loon

Gavia pacifica

Order GAVIIFORMES - Family GAVIIDAE

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1. Cool Facts
2. Description
3. Similar Species
4. Sound
5. Range
6. Habitat
7. Food
8. Behavior
9. Reproduction
10. Conservation Status
11. Other Names

The Pacific Loon is perhaps the most abundant loon in North America. It spends most of the year on the Pacific Ocean, returning to inland Arctic tundra lakes only for three months in summer to breed.

Cool Facts

• The Pacific and Arctic loons are extremely similar and were formerly considered the same species. Where the two species meet in western Alaska and eastern Siberia, the Arctic Loon has a greenish patch on its throat. Arctic Loons from the rest of Eurasia have purplish throats similar to that of the Pacific Loon.
• Pacific and Arctic loons in the waters off Japan in late winter forage cooperatively, swimming under and around schools of sand lance (a small fish) and concentrating them into an area about one meter in diameter. Japanese fishermen exploited this habit by fishing for sea bream that gathered to feed on the sand lance. With such assistance from the loons, the fishermen could earn a year's livelihood in February and March alone; as a result, the loons were worshipped as messengers from heaven. Now, this practice has ceased because of unexplained declines in loon populations, collapse of sea bream populations, and adoption of other fishing methods.

• Like other loons, the Pacific Loon walks extremely awkwardly on land, and cannot take flight from land at all. It requires about 30-50 meters of open water to take flight, flapping and pattering across the surface.

Description

• Size: 58-74 cm (23-29 in)
• Wingspan: 110-128 cm (43-50 in)
• Weight: 1000-2500 g (35.3-88.25 ounces)

• Large waterbird, medium-sized loon.
• Long body.
• Rounded head and nape.
• Relatively thin, pointed bill.
• Dark flanks.

• Breeding (Alternate) Plumage: Pale gray on the crown and nape. Fine white stripes on the sides of the neck and chest. Chin and throat dark blackish with purplish sheen. Back black with bold white spots. Bill black. Eyes red. Belly white.
  Nonbreeding (Basic) Plumage: Plain brownish-gray above and white below, with a straight border between dark coloration on the hindneck and white on the foreneck. Often shows a dark line running across the upper throat under the chin, and another dark band across the vent.

Sex Differences

Sexes alike in plumage, male larger.

Immature

Similar to nonbreeding adults; dark gray upperparts and white throat, chest, and belly.

Similar Species

• Arctic Loon is nearly identical, but has a flatter crown and white along the flanks, especially near the rump. Nonbreeding Arctic Loon lacks a "chinstrap," and does not have a band that extends all the way across the vent.
• Nonbreeding Common Loon similar, but is larger, has a jagged border between the dark hindneck and white throat, an indistinct white collar, and white crescents around the eyes.
• Winter Red-throated Loon usually has a white face with white behind the eye and an indistinct border between white and black on the neck, but it can look very similar to Pacific Loon. Red-throated Loon usually keeps its bill pointed slightly upward and has a spotted, not barred, back.

Sound

Call is a hoarse croak, often repeated. Also issues a plaintive wail.

»listen to songs of this species

Range

Summer Range

Breeds in Alaska and across northern Canada. Also in eastern Siberia.

Winter Range

Winters along the Pacific Coast from Alaska to Mexico and from Korea to China.

Habitat

Breeds on freshwater tundra lakes. Rests on open ocean during migration. Winters on ocean waters near coast, and sometimes on bays or estuaries.

Food

Fish and aquatic invertebrates.

Behavior

Foraging

Dives after prey, tracking it visually, and seizing it with bill.

Reproduction

Nest Type

Nest may be a simple depression in the ground with scant lining or a large, solid, well-formed bowl of grasses and aquatic plants, located immediately adjacent to water.

Egg Description

Variable shades of buff, brown, and olive-green.

Clutch Size

1-2 eggs.

Condition at Hatching

Downy and active; leaves nest within one or two days.

Conservation Status

Though it is abundant, the population status of Pacific Loon is not well understood. Spring migration counts in California showed a sharp decline between 1979 and 1996, but these numbers have not been substantiated by surveys of breeding birds.

Other Names

Plongeon du Pacifique (French)
Arctic Loon (before recognized as two species) (English)

Sources used to construct this page:

Russell, R. W. 2002. Pacific Loon (Gavia pacifica) and Arctic Loon (Gavia arctica). In The Birds of North America, No. 657 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.