Mountain Swiftlet vs Great Dusky Swift
Aerodramus hirundinaceus compared with Cypseloides senex
Side-by-Side Comparison
| Attribute | Mountain Swiftlet | Great Dusky Swift |
|---|---|---|
| Scientific Name | Aerodramus hirundinaceus | Cypseloides senex |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 23.0 cm (9.1 in) | 33.8 cm (13.3 in) |
| Weight | 9.700000000000001 g (0.34 oz) | 83.0 g (2.93 oz) |
| Diet | Entirely airborne insectivore; feeds on minute flying insects and web-dispersing spiders over open habitats. | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … |
| Clutch Size | 1 | 1-2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Mountain Swiftlet
High, thin twittering; 'tsit-tsit' over New Guinea highlands; echolocation clicks used in cave roosts; calls weakly in flight; colonial; flock calls produce soft chittering
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
Mountain Swiftlet
Found in montane New Guinea at 1,200–3,900 m. Resident in montane rainforest, moss forest, and subalpine grassland. Common in highlands.
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
Mountain Swiftlet
Great Dusky Swift
How to Tell Them Apart
Mountain Swiftlet
Small; dark blackish-grey upperparts; pale grey rump band; underparts pale greyish-white; forked tail; New Guinea montane endemic; similar to White-rumped Swiftlet but greyer overall and restricted to high-altitude zones.
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
Mountain Swiftlet
A small swiftlet (10-11 cm) found in montane regions of New Guinea at 1,500-3,800 m elevation. Dark grey-brown plumage. Aerial insectivore, foraging above cloud forest canopy. Colonial nester in cave entrances and rock crevices. Uses echolocation for cave navigation.
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.