An unusual gull that catches small fish and squid over the sea at night. Breeding adults show a red eye-ring, and head color changes outside the breeding plumage.
Breeding adults have a gray body, black head, red eye-ring, and pink legs. Nonbreeding adults have a white head and a thick black eye-ring.
Swallow-tailed Gulls in the Galápagos Islands forage at sea only at night during breeding. Researchers used GPS loggers at four colonies on three islands. Their trips reached pelagic waters 19–103 km from nests, while birds spent daylight mainly at or near their colonies. Night-time foraging was recorded at all four colonies.
At sea, the gulls spent about one-quarter of their time commuting and about half in area-restricted search. Three years of records from one colony showed repeated use of a broad foraging area. GPS tracks revealed that nesting islands and offshore feeding grounds are linked parts of the gulls’ breeding habitat.
An extinction-risk assessment has not been added yet.
During breeding, Swallow-tailed Gulls foraged as far as 103 km offshore from their colonies. Conservation planning can consider these offshore feeding areas and night-time travel routes together with the nesting islands.