An abundant local breeder on St. Paul Island (and less commonly on the other Pribilof Islands), this species can be easily found from mid-May through early September. It is rarely recorded before the 15th of May but becomes quite common by May 20th in most years, with peak numbers occurring in early June. It nests regularly across most of the wetlands in the Pribilofs and shows little distinction between spring migrants and local breeders. Egg laying may begin as early as mid-June with nestlings appearing at the end of the month or in early July. The nesting population on St. Paul is estimated between 50 and 100 pairs annually, with much smaller numbers breeding on St. George and Otter Islands owing to their reduced freshwater habitats. Concentrations of post-breeding birds may be seen as early as late June, with the largest numbers typically seen during July and August. Numbers remain consistent into early fall with most individuals migrating from the islands by early September and only a few records of birds lingering into late September and October.
