Great Dusky Swift vs Scarce Swift
Cypseloides senex compared with Schoutedenapus myoptilus
Side-by-Side Comparison
| Attribute | Great Dusky Swift | Scarce Swift |
|---|---|---|
| Scientific Name | Cypseloides senex | Schoutedenapus myoptilus |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 33.8 cm (13.3 in) | 25.9 cm (10.2 in) |
| Weight | 83.0 g (2.93 oz) | 26.916666666666668 g (0.95 oz) |
| Diet | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … | Obligate aerial insectivore; gathers small flying insects, winged ants, and airborne spiders during flight. |
| 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
Scarce Swift
High, sharp twittering; thin 'tsee-tsee' calls over African montane forest; rarely documented; calls from small flocks over mountain ridges; higher-pitched than larger African swifts
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.
Scarce Swift
Found in montane East Africa from Uganda and Kenya south to Malawi and Mozambique. Resident in mountain forests above 1,500 m. Scarce.
Conservation Status
Great Dusky Swift
Scarce 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 …
Scarce Swift
Dark sooty-brown overall; underparts paler grey-brown; pale grey-buff chin; moderately forked tail; African montane swift of the Albertine Rift; name reflects rarity in field; plumage uniformly dark with minimal pale …
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.
Scarce Swift
A medium-sized swift (17-18 cm) found in montane forests of eastern Africa, from Ethiopia to Malawi and Mozambique. Dark sooty-brown plumage. Aerial insectivore, foraging over forest canopy at 1,000-3,000 m elevation. Uncommon and poorly known.