Sterna aurantia
Silhouette: Sharon Wegner-Larsen · PhyloPic
In 3 days ~30% in a week ~50%
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 →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Ranthambore National Park | 🇮🇳 India | |
| 2 | Satpura National Park | 🇮🇳 India | |
| 3 | Kaziranga National Park | 🇮🇳 India | |
| 4 | Gir National Park | 🇮🇳 India | |
| 5 | Keoladeo National Park | 🇮🇳 India | |
| 6 | Nagarhole National Park | 🇮🇳 India | |
| 7 | Jim Corbett National Park | 🇮🇳 India | |
| 8 | Periyar National Park | 🇮🇳 India | |
| 9 | Bandipur National Park | 🇮🇳 India | |
| 10 | Bandhavgarh National Park | 🇮🇳 India |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Rajkot | 🇮🇳 India | |
| 2 | Kota | 🇮🇳 India | |
| 3 | Bhopal | 🇮🇳 India | |
| 4 | Hyderabad | 🇮🇳 India | |
| 5 | Chhatrapati Sambhajinagar | 🇮🇳 India | |
| 6 | Vasai-Virar | 🇮🇳 India | |
| 7 | Nagpur | 🇮🇳 India | |
| 8 | Agra | 🇮🇳 India | |
| 9 | Surat | 🇮🇳 India | |
| 10 | Vadodara | 🇮🇳 India |
With luck
About 10% of wildlife watchers report a River Tern sighting in Periyar National Park on a given day, based on 252 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 109th most-seen of the 227 birds we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
February to April
In those months about 20% of wildlife watchers report a River Tern in Periyar National Park on a given day, against under 5% in June to November, the lowest months. Those are among Periyar National Park's driest months, with about 60 mm of rain a month against 410 mm in August.
Between 3 and 6 am
Across all the parks we cover, that three-hour window holds the most River Tern sightings with a recorded time, and about half of them come between 6 am and 6 pm: it is most active around dawn and dusk.
8th of 10
Of the 10 parks where we can rate River Tern sightings, Periyar National Park ranks 8th at about 10%. The best odds are in Ranthambore National Park (India, about 40%), Satpura National Park (India, about 30%) and Kaziranga National Park (India, about 30%). All parks ranked.
GBIF citizen-science records
It is estimated from how often the River Tern is recorded against all the birds logged in Periyar National Park (252 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
