The Collaborative International Dictionary
Tern \Tern\ (t[~e]rn), n. [Dan. terne, t[ae]rne; akin to Sw. t["a]rna, Icel. [thorn]erna; cf. NL. sterna.] (Zo["o]l.) Any one of numerous species of long-winged aquatic birds, allied to the gulls, and belonging to Sterna and various allied genera.
Note: Terns differ from gulls chiefly in their graceful form, in their weaker and more slender bills and feet, and their longer and more pointed wings. The tail is usually forked. Most of the species are white with the back and wings pale gray, and often with a dark head. The common European tern ( Sterna hirundo) is found also in Asia and America. Among other American species are the arctic tern ( Sterna paradis[ae]a), the roseate tern ( Sterna Dougalli), the least tern ( Sterna Antillarum), the royal tern ( Sterna maxima), and the sooty tern ( Sterna fuliginosa).
Hooded tern. See Fairy bird, under Fairy.
Marsh tern, any tern of the genus Hydrochelidon. They frequent marshes and rivers and feed largely upon insects.
River tern, any tern belonging to Se["e]na or allied genera which frequent rivers.
Sea tern, any tern of the genus Thalasseus. Terns of this genus have very long, pointed wings, and chiefly frequent seas and the mouths of large rivers.
Wikipedia
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.
Usage examples of "river tern".
The sheriff, as it happened, was at supper in the abbots lodging, together with Prior Robert and the lord of the manor of Upton, who had just made a gift to the abbey of a fishery on the River Tern, which bordered his land.
Two brooks threaded their gentle way between the houses of the village, to merge on the southern edge and flow on to empty into the River Tern.