Great Dusky Swift vs Mottled Swift
Cypseloides senex compared with Tachymarptis aequatorialis
Side-by-Side Comparison
| Attribute | Great Dusky Swift | Mottled Swift |
|---|---|---|
| Scientific Name | Cypseloides senex | Tachymarptis aequatorialis |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 33.8 cm (13.3 in) | 41.5 cm (16.3 in) |
| Weight | 83.0 g (2.93 oz) | 94.0 g (3.32 oz) |
| Diet | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … | Entirely airborne feeder on tiny flies, gnats, and airborne arachnids; one of the most aerial … |
| Clutch Size | 1-2 | 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
Mottled Swift
Rough, coarse chatter with scratchy texture; bursts of harsh notes blending into continuous buzzy trill near nesting cliffs.
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.
Mottled Swift
Found across equatorial Africa from Guinea east to Ethiopia and south to Zambia. Resident in highland forests and rocky cliffs at 900–3,400 m.
Conservation Status
Great Dusky Swift
Mottled Swift
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 …
Mottled Swift
Large; dark brown upperparts; mottled white and brown underparts with white scales on each feather creating scaled appearance; pale throat; African montane species closely related to Alpine Swift but with …
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.
Mottled Swift
A large swift (20-22 cm) found in montane regions of eastern and southern Africa, typically at 1,500-3,000 m elevation. Dark plumage with mottled white underparts and throat. Aerial insectivore. Often seen in large flocks soaring over mountain escarpments and gorges.