Barrow’s goldeneye
Bucephala islandica
L 13″ W 31″
Habitat: Barrow’s goldeneyes attain their highest breeding population levels in western North America on moderately alkaline lakes of small to medium size in parkland areas. Open water is a necessity throughout the range, but frequently goldeneyes favor a dense growth of submerged aquatics such as sago pondweed and widgeon grass. The abundance of aquatic invertebrates may be more important than nesting cavities in determining distribution (Johnsgard 1975).
Nest: This species is not an obligate tree nester, and has been reported to use holes in banks or lava beds, rock crevices, ground under shrubs and on islands, haylofts, crows’ nests, and the outer walls of peat shelters for sheep in Iceland (Harris et al. 1954). However, the usual site is in dead stubs or trees such as aspen, Douglas-fir, and ponderosa pine within 100 feet of water (Palmer 1976). Deserted pileated woodpecker or common flicker cavities enlarged by natural decay are readily used (Palmer 1976). Cavity entrances from 3.0 to 3.9 inches in diameter, cavity depths between 9.8 and 52.9 inches, and cavity diameters between 6.5 and 9.0 inches have been reported (Johnsgard 1975). Nest boxes have been used around high lakes in the Cascade Mountains (Bellrose 1976).
Food: Food of 71 adult Barrow’s goldeneyes consisted of 36 percent insects, 19 percent molluscs, 18 percent crustaceans, 4 percent other animals, and 22 percent plants (Cottom 1939). Naiads of dragonflies and damselflies, caddisfly and midge larvae, blue mussels, amphipods, isopods, and crayfish were important animal foods, and pondweeds and wild celery were primary plant foods.