Waterfowl

Reports

Steller's Eider Spring Migration Surveys Southwest Alaska

The majority of the world's population of Steller's eiders ( Polysticta stelleri) migrates along the Bristol Bay coast of the Alaska Peninsula in the spring, crosses Bristol Bay toward Cape Peirce, then continues northward along the Bering Sea coast. Annual spring aerial surveys to monitor the population of Stellers's eiders migrating northward in southwestern Alaska have been conducted in 1992, 1993, 1994, 1997, 1998, 2000, 2001 and 2002. The survey area included sea duck habitats along the coast of southwestern Alaska from Cape Romanzof on the Yukon-Kuskokwim Delta to Chignik Bay on the south side of the Alaska Peninsula.

Since the timing of migration varies, two to three replicate shoreline surveys were conducted each spring through 1997, to increase the probability of encountering the entire population. Fiscal constraints or weather allowed only one survey each in 1998, 2000, 2001 and 2002. Numbers of Steller's eiders, other identifiable water birds, and marine mammals were recorded during the surveys. The highest Steller's eider count for each year was used as that year's estimate of the prebreeding population. Population estimates, uncorrected for observer bias, were:

1992: 137,904

1993: 88,636

1994: 107,589

1997: 90,269

1998: 84,459

2000: 68,956

2001: 58,231

2002: 54,191

The survey is documented in the following report:

Steller's Eider Spring Migration Surveys Southwest Alaska 2008( pdf)

Last Updated: December 12, 2008