Arctic Tern vs Eastern Bluebird
Sterna paradisaea 比較対象 Sialia sialis
Side-by-Side Comparison
| 属性 | Arctic Tern | Eastern Bluebird |
|---|---|---|
| 学名 | Sterna paradisaea | Sialia sialis |
| 目 | Charadriiformes | Passeriformes |
| 科 | Laridae | Turdidae |
| 保全状況 | Least Concern | Least Concern |
| 体長 | 34.0 cm (13.4 in) | 17.5 cm (6.9 in) |
| 翼開長 | 80.0 cm (31.5 in) | 27.0 cm (10.6 in) |
| 体重 | 110.0 g (3.88 oz) | 31.0 g (1.09 oz) |
| 食性 | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. | Insects in summer, berries in winter. Hunts from low perches, dropping to the ground to … |
| 一腹卵数 | 2-3 | 4-5 |
| 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.
Eastern Bluebird
Open woodland, farmland edges, orchards, and parks with scattered trees and open ground. Readily uses nest boxes.
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.
Eastern Bluebird
A rich, melodious warbled 'chur-wi, tur-a-lee' song. Both sexes sing. Call is a soft, musical 'turee'. Song is gentle and flute-like, suggesting a small thrush. Given from exposed perch.
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.
Eastern Bluebird
Eastern North America from southern Canada to Honduras and Nicaragua. Partially migratory.
保全状況
Arctic Tern
Eastern Bluebird
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
Eastern Bluebird
Males are vivid royal blue above with a rusty-red breast and white belly. Females are grey-blue with a paler rust breast.
Short, thin, dark bill
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。
Eastern Bluebird
北米に生息するヒタキで、青い上面とオレンジ色の胸を持つ。巣箱の設置プログラムにより個体数が回復した。