Scientific Name: Sterna aurantia
Name: River Tern
The river tern (Sterna aurantia) is a medium-sized tern, measuring 35 to 45 cm in length. The wingspan is 80 to 85 cm.
Size in cm:
The overall plumage of the river tern is gray and white. The upperparts are darkish gray. The underparts and underwings are whitish. The breeders 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. In wintering birds, the cap is pale gray with black streaks. The juveniles are grayish brown.
The bill is stout and yellow. Non-breeding birds have black tip to the yellow bill. The irises are blackish. The legs and feet are red.
Size in Inch
black (Bird may have more colors)
fish, aquatic insects; also crabs, other crustaceans and molluscs.
Habit and habited:
inland water bodies, rivers, tanks; almost completely absent on the sea coast.
Fairly short, shrill, staccato kiuk-kiuk in flight.
The Indian river tern or just river tern (Sterna aurantia) is a tern in the family Laridae. 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.
The diet of this river tern consists mainly of fish. Crustaceans, frogs, tadpoles and aquatic insects are their primary food. These species feed by plunge-diving.
The breeding season of these river tern species is from February to May in most their breeding grounds. They breed in colonies and are 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.
The clutch contains two to three pale buff colored eggs with dark blotches. Both the parents incubate the eggs and raise the young.