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.