Fairy Tern

The Fairy Tern, known scientifically as Sternula nereis, is a diminutive tern with a charming appearance. It boasts a pristine white body contrasted by light bluish-grey wings. A distinctive small black patch adorns the head, extending just to the eye but not reaching the bill. In breeding attire, the beak and legs take on a yellowish-orange hue, while outside the breeding season, the black crown gives way to white feathers, and the beak shows black at the tip and base. Both sexes are similar in appearance, and immature birds resemble adults in non-breeding plumage. This tern measures approximately 25 cm in length.

Identification Tips

When identifying the Fairy Tern, look for its small size and the contrast between its white body and bluish-grey wings. The black patch on the head, which does not extend to the bill, is a key feature. During breeding season, note the yellowish-orange beak and legs, which change to a black-tipped beak outside of this period.

Habitat

The Fairy Tern favors coastal environments, often seen along sheltered beaches and offshore islands.

Distribution

This species is native to the southwestern Pacific, with three subspecies distributed across Australia, New Caledonia, and northern New Zealand.

Behaviour

The Fairy Tern is a skilled fisher, hovering over the sea before plunging in to capture fish. It typically stays close to shore, especially where predatory fish are hunting small shoals. It also partakes in crustaceans, molluscs, and occasionally some plant material. Breeding occurs in spring, with colonies nesting just above the high-water mark on sandy beaches. Both parents are involved in incubation and chick rearing, with some post-fledging care observed.

Breeding

Nesting takes place in spring, with colonies forming on sheltered beaches. The nest is a simple scrape in the sand, often just above the high-water mark. The Fairy Tern typically lays one or two eggs, with both parents sharing the responsibilities of incubation and chick care.

Conservation status

The IUCN has classified the Fairy Tern as Vulnerable, with numbers declining rapidly across its range. The New Zealand subspecies is particularly at risk, being Critically Endangered. Conservation efforts, including a breeding program by the New Zealand Department of Conservation, are in place to support the species, with the population estimated at around 40 individuals in 2020.

Diet and Feeding

The diet of the Fairy Tern is predominantly fish, which it catches by expertly diving from flight. It also consumes crustaceans, molluscs, and occasionally plant matter, feeding mainly in areas where fish are abundant.

Similar Species

While similar in appearance to other terns, the Fairy Tern can be distinguished by its small size, specific plumage characteristics, and the unique color changes in its beak and legs during the breeding season.