This unique gull breeds in the Arctic and migrates mostly into the Southern Hemisphere. It is mostly encountered at sea over the open ocean but occasional stragglers such as this show up on shore or inland. This is a first cycle bird. These birds migrate while still in juvenal plumage, completing their preformative molt on the wintering grounds.
Very little is known of their vocalizations, so I was pleased to be able to hear this individual call while under observation. It was a soft nasal buzzy call, more like a tern than a gull. This is the sole member of the genus Xema. Geographic variation is slight and no subspecies are currently recognized.
Panasonic DMC-LZ5 / Nikon FS 3 / 30XWA / hand-held, no adapter.