American Robin vs Arctic Tern
Turdus migratorius 比較対象 Sterna paradisaea
Side-by-Side Comparison
| 属性 | American Robin | Arctic Tern |
|---|---|---|
| 学名 | Turdus migratorius | Sterna paradisaea |
| 目 | Passeriformes | Charadriiformes |
| 科 | Turdidae | Laridae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | 25.0 cm (9.8 in) | 34.0 cm (13.4 in) |
| 翼開長 | 36.0 cm (14.2 in) | 80.0 cm (31.5 in) |
| 体重 | 77.0 g (2.72 oz) | 110.0 g (3.88 oz) |
| 食性 | Earthworms, insects, and fruit. Famously hunts earthworms on lawns by running, stopping, and tilting its … | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. |
| 一腹卵数 | 2-4 | 2-3 |
| Population Trend | — | — |
Size Comparison
Habitat Comparison
American Robin
Lawns, parks, gardens, farmland, and forest edges. One of the most familiar birds in suburban North America.
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
American Robin
A clear, caroling song of 2-3 note phrases: 'cheerily, cheer-up, cheerio'. Sings from dawn perches. Sharp 'tut-tut-tut' alarm call and thin 'seeee' flight note.
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.
Geographic Range & Migration
American Robin
North America from Alaska and Canada to Mexico. Northern populations migrate south in winter; southern populations are largely resident.
Arctic Tern
Breeds in the Arctic and sub-Arctic. Migrates to the Antarctic, experiencing two summers per year. Found on every ocean.
保全状況
American Robin
Arctic Tern
How to Tell Them Apart
American Robin
Dark grey-brown upperparts with a warm brick-red breast and belly. White eye-ring and streaked white throat. Female slightly paler.
Bright yellow bill with a dark tip
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
About These Birds
American Robin
北米全域に分布し、春の訪れを告げる鳥として知られるツグミ（体長23〜28cm）。オレンジ色の腹と黒い頭部が特徴的。Turdus migratorius（アメリカコマツグミ）は北米最も親しまれた野鳥の一つで、芝生でミミズを引き抜く姿が日常風景として親しまれている。連邦政府と各州で厳重に保護されており、3州の州鳥に指定されている。Turdidae科。
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。