Swallow-Tailed Gull in Galápagos: Facts and Where to See It

The swallow-tailed gull forages mainly at night for squid, which rise towards the surface in the dark, and also takes small fish. Its eyes are much larger than other gulls' and have a tissue layer that reflects light back through the retina, making them especially sensitive in low light.

• A butcher's hook. It is the only species in its genus, Creagrus, from words for butcher or meat, probably after the hooked bill.
• Breeding look. Grey body, black head, red eye-ring, pink legs and a dark bill with a pale tip and a white spot at the base.
• Off-season look. White head with a thick black ring around the eye.

Swallow-tailed gulls have no fixed breeding season, so nests can be found in any month. They form loose colonies with wide gaps between nests, which the males build from stones and lava fragments on steep slopes and cliffs, on stony beaches just above the waves or under plants. Each female lays one egg; both parents incubate it for about 35 days and feed the chick for up to three months. After breeding, adults may spend four to five months hunting at sea, along the Pacific coast of South America from Ecuador to Chile.

Guide sighting records list swallow-tailed gulls at 6 sites. 2 are rated Likely: the trail on South Plaza and Darwin Bay on Genovesa. North Seymour and Punta Suárez on Española are rated Possible, and Cerro Brujo and Punta Pitt on San Cristóbal Rare. The Galapagos Conservation Trust notes a preference for the warmer waters around the eastern islands.

Swallow-tailed gulls can be seen all year round, and because breeding is not tied to a season, chicks can turn up in any month. In the next twelve months, 803 departures stop at a site where they are seen.

No, it is listed as Least Concern and protected by the national park and marine reserve. Galápagos hawks take eggs, and rats eat eggs too, without a visible effect on numbers. El Niño reduces their prey and has interrupted breeding before, after which the population recovered. Plastic and long-line fishing are possible threats.

1. Taking it for an ordinary gull. Look for the red eye-ring and black head.
2. Expecting them to fish by day. They forage mainly at night; by day you see them at their colonies.
3. Crowding a nest. Nests sit on bare stony ground; keep the 2-metre distance.