Arctic Tern vs Snowy Owl
Sterna paradisaea 比較対象 Bubo scandiacus
Side-by-Side Comparison
| 属性 | Arctic Tern | Snowy Owl |
|---|---|---|
| 学名 | Sterna paradisaea | Bubo scandiacus |
| 目 | Charadriiformes | Strigiformes |
| 科 | Laridae | Strigidae |
| 保全状況 | Least Concern | Vulnerable |
| 体長 | 34.0 cm (13.4 in) | 63.0 cm (24.8 in) |
| 翼開長 | 80.0 cm (31.5 in) | 145.0 cm (57.1 in) |
| 体重 | 110.0 g (3.88 oz) | 2100.0 g (74.08 oz) |
| 食性 | Small fish and crustaceans caught by plunge-diving from the air. Hovers briefly before diving. | Primarily lemmings on the breeding grounds, where a pair may consume over 1,500 per year. … |
| 一腹卵数 | 2-3 | 3-14 |
| 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.
Snowy Owl
Arctic tundra for breeding. Winters in open habitats resembling tundra, including prairies, airports, shorelines, and agricultural fields.
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.
Snowy Owl
Male gives a deep booming hoot 'hooooo' and a rising 'hoo-hoo' series. Also barks sharply when alarmed. Quieter than many owls; silent during long Arctic winter hunts.
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.
Snowy Owl
Circumpolar Arctic for breeding. Irruptive winter movements bring birds south to the northern United States, Europe, and Asia.
保全状況
Arctic Tern
Snowy Owl
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
Snowy Owl
Adult males are almost entirely white. Females and immatures have dark brown barring and spotting. Yellow eyes and fully feathered feet.
Dark hooked bill mostly hidden by dense facial feathering
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。
Snowy Owl
The snowy owl is the heaviest North American owl and one of the most charismatic Arctic birds. Unlike most owls, it is largely diurnal, necessitated by the continuous daylight of Arctic summers. Snowy owl irruptions — periodic mass southward movements — are tied to lemming population cycles.