Grey-rumped Swift vs Great Dusky Swift
Chaetura cinereiventris compared with Cypseloides senex
Side-by-Side Comparison
| Attribute | Grey-rumped Swift | Great Dusky Swift |
|---|---|---|
| Scientific Name | Chaetura cinereiventris | Cypseloides senex |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 20.9 cm (8.2 in) | 33.8 cm (13.3 in) |
| Weight | 16.15 g (0.57 oz) | 83.0 g (2.93 oz) |
| Diet | Obligate aerial forager catching small flies, aphids, winged termites, and airborne spiders on the wing. | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … |
| Clutch Size | 2-4 | 1-2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Grey-rumped Swift
Soft, rippling trill with gentle buzzy overtones; light aerial call carrying a faint liquid quality on calm mornings.
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
Grey-rumped Swift
Found from Nicaragua south through Central America and northwestern South America to Bolivia and Brazil. Resident in lowland forest and edge.
Great Dusky Swift
Found in eastern South America from Venezuela and the Guianas south to Bolivia and Paraguay. Resident near rocky cliffs and waterfalls.
Conservation Status
Grey-rumped Swift
Great Dusky Swift
How to Tell Them Apart
Grey-rumped Swift
Small; dark blackish-brown upperparts; pale grey rump contrasting with dark back; underparts dark grey-brown; short spiny tail; Neotropical species with the grey rump as key field mark; widespread from Caribbean …
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
Grey-rumped Swift
A medium-sized swift (11-12 cm) found in humid forests from Central America to southern Brazil. Dark grey plumage with a contrasting pale grey rump band. Short, spine-tipped tail. Aerial insectivore, foraging over forest canopy. Nests behind waterfalls and in caves.
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.