eWestern BirdsThe Quarterly Journal of Western Field Ornithologists
Vol. 34, No. 3
Western Field Ornithologists
1994–1997 Water Bird Surveys of Lake Powell
John R. Spence and Benny R. Bobowski
ABSTRACT: We conducted monthly boat surveys of aquatic birds on Lake Powell from September to April each year from 1994 to 1997. The surveys were standardized in seven designated areas on the reservoir. Each survey took three days and was done by two experienced birders and a boat pilot. In all, we recorded 72,549 detections of 57 species on 19 monthly surveys. The most commonly detected species was the American Coot, followed by the Western Grebe; these two species accounted for 81% of all detections. Species rarely recorded in southern Utah and northern Arizona but found on the surveys included the Little Blue Heron, Barrow’s Goldeneye, Greater Scaup, Herring Gull, Long-tailed Duck, Red-necked Grebe, Surf Scoter, and Pacific and Yellow-billed Loons. Species rarely recorded in winter for southern Utah and northern Arizona but detected on the surveys included the American White Pelican, Hooded Merganser, and Red-breasted Merganser. Lake Powell appears to be used primarily as a migratory stopover for aquatic species. Reservoir levels fluctuate greatly from year to year, preventing the growth of aquatic vegetation. Fish populations in the lake also fluctuate, and only in some years are sufficient to support winter populations of fish-eating species.