Arctic Tern vs Forster's Tern
Sterna paradisaea 比較対象 Sterna forsteri
Side-by-Side Comparison
| 属性 | Arctic Tern | Forster's Tern |
|---|---|---|
| 学名 | Sterna paradisaea | Sterna forsteri |
| 目 | Charadriiformes | Charadriiformes |
| 科 | Laridae | Laridae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | 34.0 cm (13.4 in) | — |
| 翼開長 | 80.0 cm (31.5 in) | 50.5 cm (19.9 in) |
| 体重 | 110.0 g (3.88 oz) | 151.25 g (5.34 oz) |
| 食性 | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. | -- |
| 一腹卵数 | 2-3 | 2-3 |
| 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.
Forster's 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.
Forster's Tern
保全状況
Arctic Tern
Forster's 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
Forster's Tern
About These Birds
Arctic Tern
キョクアジサシはあらゆる動物の中で最長の渡りを行い、毎年北極と南極を往復する約7万kmの旅をする。30年の寿命の中に、月への往復3回分に相当する飛翔距離を積み重ねる可能性がある。地球上でどの生物よりも多くの昼光を経験するこの驚異的な鳥は、太陽を追い続ける。
Forster's Tern
Forster's Tern, 33–36 cm, breeds in interior North American marshes and winters along both US coasts and into Mexico. Distinctive frosted silver upperparts and orange-based bill. In non-breeding plumage, shows a black eye-mask. Piscivore; hovers and plunge-dives in coastal bays and lagoons.