However, much is still to be learned about their food habits. Unlike the more familiar dabbling ducks, such as mallards and pintails, sea ducks do not breed until they are at least two years old, and in some years adults may forego nesting. However, sea ducks generally live longer than dabbling ducks, and although they may not produce as many young each year, their longer life span gives them more nesting opportunities. One female that was banded in Saskatchewan was 18 years old when recaptured back on the breeding grounds. They are among the last ducks to migrate to the breeding grounds and may not begin nesting until mid-June.
Females are solely responsible for incubation and brood rearing.
Following the fledging of young, females migrate to coastal molting areas where they join the males. Survey efforts have not been adequate to assess population trends for white-winged scoters throughout Alaska. Based on other surveys, the number of white-winged scoters that winter in Prince William Sound has increased since 1990. Elevated levels of cadmium were detected in the birds, but no definitive cause of death could be identified. A lack of specific information on where these birds breed and winter, and the timing of their arrival at molting areas made it impossible to locate any potential sources of contamination and help determine the cause of death.