Pacific Loon (Gavia pacifica)
Because this bird is near the top of its food chain, it is being studied to examine the magnification of chemicals in its body from pollutants in the Arctic ecosystem.
The Pacific loon’s breeding plumage consists of a grey head, a grey neck with black and white stripes down the side, and a black back with square white spots. Its dark blue throat distinguishes it from the Arctic loon of Eurasia, whose throat is greenish. These two loons were once considered to belong to the same species. In winter it is difficult to distinguish between them, although the sharp line that both species have between their black neck and white throat sets them apart from other loons. Since Arctic loons do not breed in the Canadian Arctic, however, the two are unlikely to be confused except during migration or on their wintering grounds. The Pacific loon ranges from a small 50 cm to 75 cm in length, and its body is well-adapted for diving. It has a thin, straight bill, which is sometimes curved at the sides, and a thin, streamlined body. Its legs are located far back on its body, relative to other loons, which is great for swimming and diving but makes walking difficult.
Pacific loons are common in the Beaufort sea; they prefer to nest on inland lakes on the tundra, but often feed on the shores of the Pacific Ocean. In winter these loons migrate to the Pacific coast between southern Alaska and Baja California.
Pacific loons feed mostly on small fish, and to catch them they dive deep, often searching for several minutes before resurfacing. These loons are usually found alone or in pairs, but sometimes flocks of hundreds are seen during their spring and fall migrations.