Several migratory bird species have been found to have higher reproductive success when they spent the previous winter in high quality habitat. We were interested in whether such a seasonal interaction existed for King Eiders wintering in the Bering Sea.

We captured King Eiders upon arrival on breeding grounds and used their head feathers to determine where they had spent the previous winter. We measured body mass as an indicator of body condition, and accounted for variation in body mass among sexes, study sites, and arrival dates.

Body mass did not vary among winter regions. We currently do not know why we were not able to detect a pattern, but speculate that the quality of the winter regions may not be different, or that King Eiders can compensate for poor body condition during spring migration in the important staging area in the Chukchi Sea.