Gull-billed Tern

Overview

The gull-billed tern (Gelochelidon nilotica) is a fairly large and powerful tern that resembles a Sandwich tern but possesses distinctive gull-like features. It is widely distributed across warmer regions of the world and is currently classified as Least Concern on the IUCN Red List.

Identification

• A robust body with broad wings and long legs, similar in size to a Sandwich tern.
• Distinctive short, thick, gull-like bill that is strong and black in summer adults.
• Summer plumage features grey upperparts, white underparts, a black cap, and black legs.
• Winter plumage lacks the cap, showing a dark patch through the eye similar to a Forster's tern.
• Characteristic call described as 'ker-wik'.

Habitat

This species breeds in scattered localities across southern Europe, temperate and eastern Asia, northwest Africa, and the Americas, often utilising lakes, marshes, and coastal areas including bays and earthen levees. In North America, it is associated almost solely with saltwater, coastal environments, whereas in Eurasia it is widely distributed in freshwater areas. Northern populations are migratory, wintering in regions such as Africa, the Caribbean, northern South America, southern Asia, and New Zealand.

Diet

The gull-billed tern is an atypical tern that feeds largely on insects taken in flight and also hunts over wet fields and brushy areas for amphibians and small mammals. Unlike other white terns, it does not normally plunge dive for fish, exhibiting feeding habits more similar to marsh terns. It is an opportunistic feeder, occasionally consuming dead insects such as dragonflies found on roads.

Did you know?

Its genus name, Gelochelidon, combines the Ancient Greek words for 'to laugh' and 'swallow', while the specific epithet nilotica refers to the River Nile.