Arctic Tern vs River Tern
Sterna paradisaea compared with Sterna aurantia
Side-by-Side Comparison
| Attribute | Arctic Tern | River Tern |
|---|---|---|
| Scientific Name | Sterna paradisaea | Sterna aurantia |
| Order | Charadriiformes | Charadriiformes |
| Family | Laridae | Laridae |
| Conservation Status | Least Concern | Vulnerable |
| Length | 34.0 cm (13.4 in) | — |
| Wingspan | 80.0 cm (31.5 in) | 52.4 cm (20.6 in) |
| Weight | 110.0 g (3.88 oz) | 187.5 g (6.61 oz) |
| Diet | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. | -- |
| Clutch Size | 2-3 | 3-4 |
| Population Trend | — | — |
Size Comparison
Habitat Comparison
Arctic Tern
Breeds on coastal and tundra habitats. Spends most of its life at sea over the open ocean. Nests in colonies on beaches and rocky shores.
Song & Call Comparison
Arctic Tern
A sharp, grating 'kree-yah' alarm call. Also gives 'kik-kik-kik' near the nest. Highly aggressive vocally during the Arctic breeding season. Calls are harsh and insistent.
River Tern
Geographic Range & Migration
Arctic Tern
Breeds in the Arctic and sub-Arctic. Migrates to the Antarctic, experiencing two summers per year. Found on every ocean.
River Tern
Conservation Status
Arctic Tern
River Tern
How to Tell Them Apart
Arctic Tern
Pale grey upperparts, white underparts with a black cap. Blood-red bill and short red legs. Deeply forked tail streamers. Winter adults lose the full black cap.
Slender, pointed, bright red bill
River Tern
About These Birds
Arctic Tern
The Arctic tern holds the record for the longest known migration of any animal, traveling roughly 70,000 km annually from Arctic to Antarctic and back. Over its 30-year lifespan, it may fly the equivalent of three round trips to the Moon. This remarkable bird experiences more daylight than any other creature on Earth.
River Tern
River Tern, 38–43 cm, is a large freshwater tern of South and Southeast Asia, found along major rivers from Pakistan to Thailand. Yellow-orange bill, grey back, black cap in breeding plumage. Piscivore; plunge-dives into clear river water. Near Threatened due to river sand-mining and disturbance.