Polynesian Swiftlet vs Great Dusky Swift
Aerodramus leucophaeus compared with Cypseloides senex
Side-by-Side Comparison
| Attribute | Polynesian Swiftlet | Great Dusky Swift |
|---|---|---|
| Scientific Name | Aerodramus leucophaeus | Cypseloides senex |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 23.7 cm (9.3 in) | 33.8 cm (13.3 in) |
| Weight | 13.4 g (0.47 oz) | 83.0 g (2.93 oz) |
| Diet | Aerial insectivore catching tiny flying insects, midges, and airborne spiders in fast low-altitude flight near … | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … |
| Clutch Size | 2 | 1-2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Polynesian Swiftlet
High twittering; thin 'chip-chip' over French Polynesian islands; echolocation clicks in cave roosts; light-colored underparts distinguish it visually; calls unremarkable
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
Polynesian Swiftlet
Found across French Polynesia including the Society Islands, Marquesas, and Tuamotu. Resident in forest and open areas; nests in sea caves.
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
Polynesian Swiftlet
Great Dusky Swift
How to Tell Them Apart
Polynesian Swiftlet
Small; dark brown-grey upperparts with minimal gloss; pale grey rump band; underparts whitish-grey; forked tail; East Polynesian endemic from Society Islands; slightly more uniformly dark than some Pacific congeners.
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
Polynesian Swiftlet
A small swiftlet (10-11 cm) found across French Polynesia, including the Society, Marquesas, and Austral Islands. Dark grey plumage with whitish underparts. Aerial insectivore. Colonial cave nester. Population fragmented across widely scattered Pacific islands.
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.