Arctic Tern vs River Tern
Sterna paradisaea 对比 Sterna aurantia
Side-by-Side Comparison
| 属性 | Arctic Tern | River Tern |
|---|---|---|
| 学名 | Sterna paradisaea | Sterna aurantia |
| 目 | Charadriiformes | Charadriiformes |
| 科 | Laridae | Laridae |
| 保护状况 | Least Concern | Vulnerable |
| 体长 | 34.0 cm (13.4 in) | — |
| 翼展 | 80.0 cm (31.5 in) | 52.4 cm (20.6 in) |
| 体重 | 110.0 g (3.88 oz) | 187.5 g (6.61 oz) |
| 食性 | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. | -- |
| 产卵数 | 2-3 | 3-4 |
| 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.
River 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.
River Tern
保护状况
Arctic Tern
River 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
River Tern
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。
River Tern
River Tern, 38–43 cm, is a large freshwater tern of South and Southeast Asia, found along major rivers from Pakistan to Thailand. Yellow-orange bill, grey back, black cap in breeding plumage. Piscivore; plunge-dives into clear river water. Near Threatened due to river sand-mining and disturbance.