Sabine's Gull (Xema sabini) Nesting Aggregations in Western Alaska

Abstract

Nest surveys on Alaska's Yukon-Kuskokwim Delta provide annual information on phenology, egg production, nesting effort, habitat use, and predation for waterfowl, cranes, loons, gulls, and terns. In 2012, atypically cold May temperatures delayed snowmelt and breakup of lakes, ponds, sloughs and rivers. In response, waterfowl nest initiation and hatch occurred six to ten days later than long-term means . Despite late nesting initiation in 2012, average timing of waterfowl nesting has advanced seven days since standardized plot data collection began in the 1980s. In 2012, the number of spectacled eider nests was the highest estimate since 1987. The proportion of active nests (an index to nest success) indicated that nest success was good and clutch size was moderate relative to long-term means. Numbers of spectacled eider nests have increased significantly during the most recent decade, and the population is stable over the 28-year span of this survey . Geese (cackling Canada, emperor, and white-fronted) exhibited moderate or high production of nests and eggs, and good to excellent nest success; yet clutch size was very low relative to long-term means. For cackling Canada geese, emperor geese, and white-fronted geese, numbers of nests have increased significantly over the long-term (1985-2012) and short-term (2003-2012) periods.The Spectacled Eider Recovery Team identified annual nest surveys as the primary method to assess of population status relative to recovery criteria for the Yukon-Kuskokwim Delta (YKD) subpopulation. Based on these nest surveys, the Yukon-Kuskokwim Delta subpopulation of spectacled eider is close to the benchmark criteria for consideration of Dean Demarest