Arctic Tern vs Eastern Bluebird
Sterna paradisaea 对比 Sialia sialis
Side-by-Side Comparison
| 属性 | Arctic Tern | Eastern Bluebird |
|---|---|---|
| 学名 | Sterna paradisaea | Sialia sialis |
| 目 | Charadriiformes | Passeriformes |
| 科 | Laridae | Turdidae |
| 保护状况 | Least Concern | Least Concern |
| 体长 | 34.0 cm (13.4 in) | 17.5 cm (6.9 in) |
| 翼展 | 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 … |
| 产卵数 | 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.
保护状况
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
北极燕鸥进行所有动物中最长的迁徙，每年从北极繁殖地飞往南极越冬地，往返距离超过70,000公里。体型纤细，翼展约80厘米，全身主要为白色，具黑色头冠和红色喙。无危；繁殖于北极和亚北极海岸及岛屿，全球种群约200万只。
Eastern Bluebird
北美幸福的象征。通过安装巢箱使种群得以恢复。冬季形成松散群体。