River tern

For the river in Shropshire, England, see River Tern.

River tern
File:Sterna aurantia (Ranganathittu).jpg
In breeding plumage
Conservation status
Near Threatened (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Charadriiformes
Family:	Sternidae
Genus:	Sterna
Species:	S. aurantia
Binomial name
Sterna aurantia (Gray,JE, 1831)

File:River Tern (Sterna aurantia)- Immatures W IMG 9725.jpg

Immature

File:River Tern (Sterna aurantia)- Adult & Immature W IMG 9721.jpg

Adult and immature

The Indian river tern or just river tern (Sterna aurantia) is a bird in the tern family . It is a resident breeder along inland rivers from Iran east into the Indian Subcontinent and further to Myanmar to Thailand, where it is uncommon. Unlike most Sterna terns, it is almost exclusively found on freshwater, rarely venturing even to tidal creeks.

This species breeds from March to May in colonies in less accessible areas such as sandbanks in rivers. It nests in a ground scrape, often on bare rock or sand, and lays three greenish-grey to buff eggs, which are blotched and streaked with brown.

This is a medium-sized tern, 38–43 cm long with dark grey upperparts, white underparts, a forked tail with long flexible streamers, and long pointed wings. The bill is yellow and the legs red. It has a black cap in breeding plumage. In the winter the cap is greyish white, flecked and streaked with black, there is a dark mask through the eye, and the tip of the bill becomes dusky.

The sexes are similar but juveniles have a brown head, brown-marked grey upperparts, grey breast sides and white underparts. The bill is yellowish with a dark tip

As with other Sterna terns, the river tern feeds by plunge-diving for fish, crustaceans, tadpoles and aquatic insects in rivers, lakes, and tanks. Its numbers are decreasing due to the pollution of their habitat.

References

• Birds of India by Grimmett, Inskipp and Inskipp'Seabirds: An Identification Guide by Harrison, Peter ISBN 0-7470-1410-8

Gallery

• River Tern (Sterna aurantia) resting on the banks W IMG 9696.jpg

  Resting on the banks at Pocharam lake, Andhra Pradesh

• River Tern (Sterna aurantia) with a Snail W IMG 9682.jpg

  With a snail at Pocharam lake, Andhra Pradesh

• River Tern (Sterna aurantia) near Hyderabad W IMG 4948.jpg

  In breeding plumage in Hyderabad

• River Tern (Sterna aurantia)- Non-breeding at Hyderabad, AP W IMG 7473.jpg

  In non-breeding plumage in Hyderabad

• River tern-Nest 09 - Koyna 042011.JPG

  Nest at Koyna lake

• River tern-Chick 01 - Koyna 042011.JPG

  Chick at Koyna lake

• River Tern Chick.JPG

  Chick at Ranganthittu Bird Sanctuary

External links

• A documentary on the life of River Terns by Amoghavarsha JS