Yellow-billed Loon

The Yellow-billed Loon, also known as the White-billed Diver, is a majestic bird, the largest of its family. In its breeding attire, it sports a black head, a checkered black-and-white mantle, and striking white underparts. The non-breeding plumage is more subdued, with a white chin and foreneck. Its most notable feature is the elongated straw-yellow bill, which appears slightly uptilted due to its straight culmen.

Identification Tips

Adults in breeding plumage exhibit a purple sheen on their heads and necks, contrasting with their black and white bodies. The juvenile Yellow-billed Loon is less distinct, with drabber coloration. The species' large size, combined with its distinctive bill, aids in its identification.

Habitat

This Arctic bird breeds along the coasts of the Arctic Ocean, favoring freshwater pools or lakes within the tundra. It is also known to nest along rivers, estuaries, or coastal areas, generally avoiding forested regions.

Distribution

The Yellow-billed Loon breeds as far north as 78° N and winters mainly at sea along the northern Pacific Ocean and northwestern Norway. It has been recorded as a breeding bird in Russia, Canada, and the United States. During winter, it can be found as far south as 35° N off the coast of Japan and has been observed as a vagrant in over 20 countries.

Behaviour

Breeding pairs of Yellow-billed Loons are long-lasting and territorial. They begin nesting in early June, timing it with the spring thaw. The nest is constructed close to water, and copulation occurs on land. The pair vigorously defends its territory but may congregate with others at prime fishing spots later in the season.

Song & Calls

The call of the Yellow-billed Loon is an eerie wailing, distinguishable by its lower pitch compared to the Common Loon.

Breeding

The female lays two eggs, which are a light purple-brown with darker blotches, providing camouflage. Incubation lasts approximately 27 to 29 days.

Diet and Feeding

Primarily piscivorous, the Yellow-billed Loon dives underwater to catch fish. It also consumes crustaceans, molluscs, and annelids, particularly when feeding its young. Interestingly, it defecates on land, possibly to avoid parasite transmission in its aquatic environment.

Conservation status

The IUCN has classified the Yellow-billed Loon as Near Threatened due to a moderately rapid population decline, with unsustainable subsistence harvesting cited as a primary threat. It is protected under the Agreement on the Conservation of African-Eurasian Migratory Waterbirds and the Migratory Bird Treaty Act of 1918 in the Americas.