Arctic Tern vs Grey-backed Tern
Sterna paradisaea compared with Onychoprion lunatus
Side-by-Side Comparison
| Attribute | Arctic Tern | Grey-backed Tern |
|---|---|---|
| Scientific Name | Sterna paradisaea | Onychoprion lunatus |
| Order | Charadriiformes | Charadriiformes |
| Family | Laridae | Laridae |
| Conservation Status | Least Concern | Least Concern |
| Length | 34.0 cm (13.4 in) | — |
| Wingspan | 80.0 cm (31.5 in) | 52.2 cm (20.6 in) |
| Weight | 110.0 g (3.88 oz) | 126.21666666666665 g (4.45 oz) |
| Diet | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. | -- |
| Clutch Size | 2-3 | 1 |
| 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.
Grey-backed 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.
Grey-backed Tern
Conservation Status
Arctic Tern
Grey-backed 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
Grey-backed 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.
Grey-backed Tern
Grey-backed Tern, 35–37 cm, is a Pacific seabird breeding on islands from Hawaii to Micronesia and Polynesia. Pale grey back distinguishes it from the similar Bridled Tern; white below with black cap. Piscivore; surface-dips and shallow plunge-dives. Largely pelagic when not breeding.