White-rumped Swiftlet vs Great Dusky Swift
Aerodramus spodiopygius compared with Cypseloides senex
Side-by-Side Comparison
| Attribute | White-rumped Swiftlet | Great Dusky Swift |
|---|---|---|
| Scientific Name | Aerodramus spodiopygius | Cypseloides senex |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 23.4 cm (9.2 in) | 33.8 cm (13.3 in) |
| Weight | 7.4 g (0.26 oz) | 83.0 g (2.93 oz) |
| Diet | Feeds on aerial plankton including tiny flies and spiders; forages in large noisy flocks above … | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … |
| Clutch Size | 1-2 | 1-2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
White-rumped Swiftlet
Rapid thin twittering; high 'tsit-tsit' notes over Pacific islands; echolocation clicks in caves; colonial; produces soft chattering in roost cavities; unremarkable call
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
White-rumped Swiftlet
Found across the southwestern Pacific including Fiji, Samoa, Tonga, and Vanuatu east to the Cook Islands. Resident from coast to mountains.
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
White-rumped Swiftlet
Great Dusky Swift
How to Tell Them Apart
White-rumped Swiftlet
Small; dark brownish-black upperparts with faint gloss; white rump patch contrasting sharply with dark back and tail; underparts pale greyish-white; forked tail; widespread Pacific species with diagnostically bright white rump.
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
White-rumped Swiftlet
A small swiftlet (10-11 cm) widespread across the western Pacific from the Bismarck Archipelago to Fiji and Samoa. Dark plumage with a conspicuous white rump band. Aerial insectivore. Colonial cave nester using echolocation. One of the most widespread Pacific swiftlets.
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.