River Tern

About the River Tern

The river tern or Indian river tern (Sterna aurantia) is a tern in the family Laridae, the largest species currently included in the genus Sterna of typical terns. It is a resident breeder along inland rivers from Pakistan east through the Indian subcontinent, to Myanmar, Thailand, and Cambodia, where it is uncommon. Unlike most Sterna terns, it is almost exclusively found on freshwater, rarely venturing even to tidal creeks.

It is a medium-large tern, 38–46 cm long with an 80–85 cm wingspan, distinctly larger than any other species in Sterna and more comparable in size to a Sandwich tern (Thalasseus sandvicensis) or a lesser crested tern (T. bengalensis). It has dark grey upperparts, white or very pale grey underparts, a forked tail with long flexible streamers, and long pointed wings with pale grey primaries. The bill is stout for a tern, bright yellow in summer and duller yellow with a dusky tip in winter, and the legs bright red. It has a black cap in breeding plumage, which is more extensive than in other Sterna terns, extending well below the eye instead of barely or not below the eye. In winter the cap is greyish white, flecked and streaked with black, with... Wikipedia →