Great Dusky Swift vs Madagascar Spinetail
Cypseloides senex compared with Zoonavena grandidieri
Side-by-Side Comparison
| Attribute | Great Dusky Swift | Madagascar Spinetail |
|---|---|---|
| Scientific Name | Cypseloides senex | Zoonavena grandidieri |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 33.8 cm (13.3 in) | 24.9 cm (9.8 in) |
| Weight | 83.0 g (2.93 oz) | 9.25 g (0.33 oz) |
| Diet | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … | Obligate aerial forager on small insects and airborne spiders; among the fastest-flying of all swift … |
| Clutch Size | 1-2 | -- |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
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
Madagascar Spinetail
Rapid, high-pitched chittering calls in flight; thin, insect-like trilling notes delivered in quick bursts above forest canopy.
Geographic Range & Migration
Great Dusky Swift
Found in eastern South America from Venezuela and the Guianas south to Bolivia and Paraguay. Resident near rocky cliffs and waterfalls.
Madagascar Spinetail
Endemic to Madagascar. Resident in forest edge and open areas across the island. Nests in hollow palms and rock crevices.
Conservation Status
Great Dusky Swift
Madagascar Spinetail
How to Tell Them Apart
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 …
Madagascar Spinetail
Tiny; dark brown-black upperparts; contrasting white rump patch; underparts pale whitish; short spiny tail; Malagasy endemic; white rump is the most diagnostic feature, recalling swiftlets but with characteristic spinetail tail …
About These Birds
Great Dusky Swift
A large swift (18-20 cm) of southeastern Brazil, eastern Paraguay, and northeastern Argentina. Dark sooty-brown plumage. Aerial insectivore, foraging over forested gorges and waterfalls. Nests in large colonies behind waterfalls. The largest member of the genus Cypseloides.
Madagascar Spinetail
A medium-sized spinetail swift (12-13 cm) endemic to Madagascar. Dark plumage with a pale rump and short, spine-tipped tail. Aerial insectivore, foraging over forest and woodland. Nests in tree hollows. Found throughout Madagascar's remaining forested areas.