Red-throated Loon vs Yellow-billed Loon

Red-throated Loon

Gavia stellata

Large1.5 kgWetland

Like the other members of its genus, the red-throated loon is well adapted to its aquatic environment: its dense bones help it to submerge, its legs—in their set-back position—provide excellent propulsion, and its body is long and streamlined. Even its sharply pointed bill may help its underwater streamlining. Its feet are large, its front three toes are fully webbed, and its tarsus is flattened, which reduces drag and allows the leg to move easily through the water. Voice: The adult red-throated loon has a number of vocalisations, which are used in different circumstances. In flight, when passing conspecifics or circling its own pond, it gives a series of rapid yet rhythmic goose-like cackles—kaa-kaa-kaa or kak-kak-kak, at roughly five calls per second. Its warning call, if disturbed by humans or onshore predators, is a short croaking bark.

ID text from Wikipedia, CC BY-SA 4.0

Recorded by Grégoire Chauvot · Flight call · Kvaløyvågen, Tromsø, Troms og Finnmark, Norway · CC0

Photo: Hobbyfotowiki · CC0

Yellow-billed Loon

Gavia adamsii

Huge4.9 kgWetland

With a length of 76 to 97 cm (30 to 38 in), a wingspan of 135 to 160 cm (53 to 63 in), and a weight ranging from 4 to 6.4 kg (8.8 to 14.1 lb), the yellow-billed loon is the largest member of the loon (diver) family. The adult is primarily black and white in breeding plumage, with a purple gloss on its head and neck. Appleby, R.H.; Madge, S.C.; Mullarney, Killian (1986). "Identification of divers in immature and winter plumages". British Birds. 79 (8): 365–391.

ID text from Wikipedia, CC BY-SA 4.0

Photo: Ryan Askren USGS, Alaska Science Center · Public domain

Photos and recordings are credited to their authors under the licence shown. Full profiles: Red-throated Loon and Yellow-billed Loon.