Pacific Loon

The Pacific loon, also known as the Pacific diver (Gavia pacifica), is a medium-sized bird belonging to the loon, or diver, family. It is a sleeker, smaller counterpart to the common loon, with a distinctive grey head, black throat with purple reflections, white underparts, and a chequered black-and-white mantle. The bill of the Pacific loon is grey or whitish and shaped like a dagger.

Identification Tips

In breeding plumage, the Pacific loon can be distinguished from the similar black-throated loon by the absence of a white flank patch. During winter, the red-throated loon may appear similar, but the Pacific loon has a more contrasting pattern between the crown, hindneck, and throat, and lacks the upturned bill of the red-throated loon. The legs of the Pacific loon are positioned towards the rear, aiding in underwater foraging but making land movement challenging.

Habitat

The Pacific loon breeds on tundra lakes and winters in the open ocean or other large bodies of water.

Distribution

This species breeds primarily in northern Canada and eastern Siberia and winters along the Pacific coast of North America. It has also been recorded as a vagrant in various countries, including Greenland, Hong Kong, Great Britain, Spain, Finland, and Switzerland.

Behaviour

The Pacific loon is known for its aggressive territoriality, defending its nesting area with vigor. It constructs its nest on the ground near deep lakes using piled-up vegetation. The species is socially monogamous, with high territory retention rates, and may migrate in flocks.

Song & Calls

The Pacific loon has a repertoire of calls, including a sharp "ark," a haunting "oo-loo-lee" wail, and a series of "kok-kok-kok-kok" calls. These vocalizations are most active during the spring and summer months.

Breeding

The loon lays one to two light buff or green eggs with brown spots, which hatch after an incubation period of 23 to 25 days. The nests are built close to water, and both parents are involved in defending the territory and raising the young.

Diet and Feeding

Specializing in fish, the Pacific loon catches its prey underwater and is known to forage in groups, driving schools of fish towards the surface. It tends to feed closer to shore compared to other loon species.

Conservation status

The Pacific loon is currently classified as Least Concern, with a population that is increasing and spread over a large range. Conservation efforts are focused on monitoring populations and breeding behaviors, with concerns about environmental pollutants like mercury and the impact of human activities on nesting success.