Bare-legged Swiftlet vs Great Dusky Swift
Aerodramus nuditarsus 비교 대상 Cypseloides senex
Side-by-Side Comparison
| 속성 | Bare-legged Swiftlet | Great Dusky Swift |
|---|---|---|
| 학명 | Aerodramus nuditarsus | Cypseloides senex |
| 목 | Caprimulgiformes | Caprimulgiformes |
| 과 | Apodidae | Apodidae |
| 보전 상태 | Least Concern | Least Concern |
| 체장 | — | — |
| 날개 폭 | 25.0 cm (9.8 in) | 33.8 cm (13.3 in) |
| 체중 | 13.3 g (0.47 oz) | 83.0 g (2.93 oz) |
| 식성 | Obligate aerial insectivore; catches minute flies, beetles, and aerial spiders while foraging near cave roosts. | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … |
| 산란 수 | -- | 1-2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Bare-legged Swiftlet
High thin twittering; 'tsit-tsit' over New Guinea lowlands; echolocation clicks in cave roosts; calls weakly in flight; colonial nester producing soft flock chattering
Great Dusky Swift
Loud, churring trill; harsher and louder than other Cypseloides; calls over Iguacu Falls and major Neotropical waterfalls; buzzy 'bzzzt-bzzzt' in aerial groups
Geographic Range & Migration
Bare-legged Swiftlet
Found in lowland New Guinea and adjacent islands. Resident in lowland rainforest and forest edge. Little-known Papuan endemic.
Great Dusky Swift
Found in eastern South America from Venezuela and the Guianas south to Bolivia and Paraguay. Resident near rocky cliffs and waterfalls.
보전 상태
Bare-legged Swiftlet
Great Dusky Swift
How to Tell Them Apart
Bare-legged Swiftlet
Small; dark grey-brown upperparts; pale rump band; underparts whitish-grey; forked tail; bare unfeathered tarsi distinctive among swiftlets; New Guinea lowland cave-nesting species; bare legs visible at nest but rarely field-observable.
Great Dusky Swift
Very large; entirely dark sooty-brown with pale grey forehead and chin scaling; slightly paler underparts; broad wings; largest Cypseloides swift; South American waterfall specialist with dusky uniform plumage and imposing …
About These Birds
Bare-legged Swiftlet
특히 저지대와 구릉지 삼림의 뉴기니에 서식하는 작은 칼새류(10~11cm). 비늘 없는 발가락이 특징이다. 공중 식충성이다.
Great Dusky Swift
18–20 cm의 대형 칼새로 브라질 동남부·파라과이 동부·아르헨티나 북동부에 서식. 어두운 그을린 갈색 깃털. 삼림 협곡과 폭포 위를 날며 먹이를 구하는 공중 곤충식성. 폭포 뒤에 대규모 집단으로 둥지를 튼다. Cypseloides 속의 가장 큰 종.