The most reliable jaeger species in the Pribilofs, this species may be seen at almost any time from early May to early October. Sightings of this species are most likely after May 20th with a peak in late May, and a smaller summer peak in early July; however, its likelihood of being observed does not decline until late August and sightings are not unusual until at least September 20th in the fall. The latest records of this species come from mid- October, though this may not be the true end of sightings.
Light-morph adults predominate in the Pribilofs, though dark-morph adults are seen on occasion with intermediate-morph and dark-morph juveniles both quite common.
