American Crow vs Arctic Tern
Corvus brachyrhynchos 比較対象 Sterna paradisaea
Side-by-Side Comparison
| 属性 | American Crow | Arctic Tern |
|---|---|---|
| 学名 | Corvus brachyrhynchos | Sterna paradisaea |
| 目 | Passeriformes | Charadriiformes |
| 科 | Corvidae | Laridae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | 45.0 cm (17.7 in) | 34.0 cm (13.4 in) |
| 翼開長 | 99.0 cm (39.0 in) | 80.0 cm (31.5 in) |
| 体重 | 450.0 g (15.87 oz) | 110.0 g (3.88 oz) |
| 食性 | Highly omnivorous — insects, earthworms, seeds, fruit, eggs, nestlings, carrion, and human food waste. Among … | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. |
| 一腹卵数 | 3-7 | 2-3 |
| Population Trend | — | — |
Size Comparison
Habitat Comparison
American Crow
Extremely adaptable — found in farmland, open woodland, suburban neighborhoods, parking lots, and urban parks.
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 Crow
Classic 'caw-caw-caw' repeated in series. Family groups use distinct dialects. Also gives rattling, knocking, and a short 'cah' flight call. Highly social and vocal.
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 Crow
North America from southern Canada through the United States to northern Mexico.
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 Crow
Arctic Tern
How to Tell Them Apart
American Crow
All black with a slight glossy sheen. Squared-off tail and smooth throat distinguish it from the common raven.
Straight, sturdy black bill smaller than a raven's
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 Crow
北米全域に広く分布する大型のカラス（体長40〜53cm）。全身光沢のある黒で、知性が高く強い社会性を持つ。Corvus brachyrhynchos（アメリカガラス）は北米で最もよく見られるカラスで、交通量の多い道路に堅い木の実を置いて車に割らせる「道具使用」が観察されている。Corvidae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。