Reproductive ecology and habitat use of Pacific Black Scoters (Melanitta nigra americana) nesting on the Yukon-Kuskokwim Delta, Alaska

Schamber, J. L.
Broerman, F. J.
Flint, Paul L.
Publication Date: 

Abstract.—Abundance indices of Black Scoters (Melanitta nigra americana) breeding in Alaska indicate a long- term population decline without obvious cause(s). However, few life history data are available for the species in North America. In 2001-2004, information was collected on nesting habitat and reproductive parameters (i.e. com- ponents of productivity) from a population of Black Scoters nesting on the Yukon-Kuskokwim Delta, Alaska. A total of 157 nests were found over four years. Primarily, nests were among dense vegetation in shrub edge habitat, pre- dominantly dwarf birch (Betula glandulosa) and Alaska spiraea (Spiraea beauverdiana), an average of 58 m from water. Females initiated nests from 11 June and 17 July across years. Clutch size averaged 7.5 eggs and did not vary annu- ally. Nest success was highly variable among years and ranged from 0.01 to 0.37. Duckling survival to 30 days old varied among years, and ranged from 0.09 - 0.35. Nest success was poor in three of four years, likely due to predation by Red Fox (Vulpes vulpes). Black Scoters appear to have low but variable productivity, consistent with life-history patterns of other sea duck species. Information gained will direct future demographic research on Black Scoters, and highlights knowledge gaps impeding management strategies needed for population recovery. Received 10 June
2009, accepted 17 December 2009.
Key words.—Alaska, Black Scoter, duckling survival, habitat selection, initiation date, Melanitta nigra, nest suc- cess, sea duck, Yukon-Kuskokwim Delta.

Citation Information: 
Waterbirds 33(2): 129-139, 2010