Mayr's Swiftlet vs Great Dusky Swift
Aerodramus orientalis compared with Cypseloides senex
Side-by-Side Comparison
| Attribute | Mayr's Swiftlet | Great Dusky Swift |
|---|---|---|
| Scientific Name | Aerodramus orientalis | Cypseloides senex |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Data Deficient | Least Concern |
| Length | — | — |
| Wingspan | 25.0 cm (9.8 in) | 33.8 cm (13.3 in) |
| Weight | 13.3 g (0.47 oz) | 83.0 g (2.93 oz) |
| Diet | Feeds aerially on tiny flying insects and drifting spiders; often forages in mixed-species flocks over … | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … |
| Clutch Size | -- | 1-2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Mayr's Swiftlet
Thin twittering calls; 'tsit-tsit' notes; echolocation clicks used in caves; data deficient species from Melanesia; poorly documented; calls indistinguishable from related species
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
Mayr's Swiftlet
Found in the mountains of New Guinea (Jayawijaya and Saruwaged ranges) at 1,500–3,400 m. Resident in montane forest. Poorly known.
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
Mayr's Swiftlet
Great Dusky Swift
How to Tell Them Apart
Mayr's Swiftlet
Small; dark brownish-grey upperparts with slight gloss; pale grey rump band; underparts pale whitish-grey; forked tail; Eastern Melanesian swiftlet; closely resembles Uniform Swiftlet but differs in rump contrast and geographic …
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
Mayr's Swiftlet
A small swiftlet (10-11 cm) found in New Guinea and adjacent islands. Dark plumage. Aerial insectivore. Colonial cave nester using echolocation. Named after Ernst Mayr. Taxonomy has been revised repeatedly. Limited ecological data available.
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.