About Gavia pacifica (Lawrence, 1858)
Breeding adult Pacific loons are smaller and sleeker than common loons. They measure 58–74 cm (23–29 in) in total length, have a 110–128 cm (43–50 in) wingspan, and weigh 1–2.5 kg (2.2–5.5 lb). Breeding adults have a grey head, black throat with purple reflections, white underparts, and a chequered black-and-white mantle. Non-breeding plumage is duller, with white coloring on the chin and foreneck. The Pacific loon has a dagger-shaped grey or whitish bill. In all plumages, this species can be told apart from the very similar black-throated loon by its lack of a white flank patch. When seen in winter, the Pacific loon can be distinguished from the red-throated loon: red-throated loons have a paler overall appearance, less contrast between the crown, hindneck and throat, and an upturned-looking bill. Like other members of Gaviiformes, the Pacific loon has legs placed toward the back of its body. This leg position makes walking on land difficult, but helps the loon forage for food efficiently underwater. This body structure makes taking off from land practically impossible; Pacific loons need 27 to 46 meters (30 to 50 yards) of open water to take flight successfully. This takeoff distance requirement limits the number of lakes that Pacific loons can use for breeding and foraging. The Pacific loon breeds on tundra lakes and winters on the open ocean or other large bodies of water. It breeds mainly in northern Canada and eastern Siberia, and winters along the Pacific coast of North America.
