Order: Charadriiformes

Family: Laridae

Scientific name: Sterna aurantia, J.E. Gray, 1831.

IUCN Red list status-Near Threatened

Did you know?

  1. The River Tern is also known as Indian River Tern.

Description

The River Tern is 35 to 45 cm long and weighs 100-120 Gms. The overall plumage of the river tern is grey and white. The upperparts are darkish grey. The under parts and under wings are whitish. The breeding birds have black cap, merging with the black mask over the eyes. The cap extends to the nape. The wings are long and pointed. The forked tail has long flexible streamers. The bill is stout and yellow. Non-breeding birds have black tip to the yellow bill. The irises are black and legs and feet are red. Both sexes look similar. The juveniles are greyish brown.

Diet

The diet of River Tern consists mainly of fish, crustaceans, frogs, tadpoles and aquatic insects. They feed by plunge-diving into the water bodies. From time to time, it plunges with is closed wings, often becoming completely submerged but soon reappears with the prey held across the bill. As it resumes its flight, the victim is jerked up in the air and swallowed head foremost. The forage time is mainly day and it is done solitarily or in groups.

Habitat

The habitats of River Tern include freshwater lakes, streams, rivers, inland waters and creeks. Sometimes they are also found in intertidal mudflats, marshes, lagoons and estuaries. In India it is distributed throughout the union. It is also seen in Pakistan, Bangladesh and Myanmar.

Reproductive Behaviour

The breeding season of River Tern is from February to May. They are colonial breeders, monogamous and territorial. The nesting sites of the river terns are located in less accessible areas such as sandbanks and sand islands in streams and water bodies. The nest is a shallow scrape on dry open ground or in the cover of grass. The nesting sites are prone to flooding. Normally 2-3 three pale buff coloured eggs with dark blotches are laid. Both the parents incubate the eggs for 21-28 days and raise the young.

Call

The call is a loud rich “kyeeer…kyeeer” or “kree…kree” or high “kiuck” sound.

Related Species and Sub Species

  • Black-naped Tern (Sterna sumatrana).
  • Common Tern (Sterna hirundo).
  • White-cheeked Tern (Sterna repressa).
  • Arctic tern (Sterna paradisaea).
  • Black Bellied tern (Sterna acuticauda).

Migratory Behaviour

Widespread Resident, but uncommon.