Mascarene Swiftlet vs Great Dusky Swift
Aerodramus francicus compared with Cypseloides senex
Side-by-Side Comparison
| Attribute | Mascarene Swiftlet | Great Dusky Swift |
|---|---|---|
| Scientific Name | Aerodramus francicus | Cypseloides senex |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Near Threatened | Least Concern |
| Length | — | — |
| Wingspan | 21.8 cm (8.6 in) | 33.8 cm (13.3 in) |
| Weight | 10.419999999999998 g (0.37 oz) | 83.0 g (2.93 oz) |
| Diet | Aerial insectivore consuming minute dipterans, midges, and ballooning spiders caught in continuous fast flight. | 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
Mascarene Swiftlet
Thin, rapid chittering; soft 'tsit' notes over Reunion and Mauritius; echolocation clicks in cave roosts; endemic island species; calls weakly; colonial roosting produces faint noise
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
Mascarene Swiftlet
Endemic to the Mascarene Islands of Réunion and Mauritius in the southwestern Indian Ocean. Nests in sea caves and rock crevices.
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
Mascarene Swiftlet
Great Dusky Swift
How to Tell Them Apart
Mascarene Swiftlet
Small; dark blackish-brown upperparts with slight greenish gloss; pale buff-grey rump band; pale grey-white underparts; forked tail; Mascarene Island endemic of Réunion and Mauritius with slightly dusky-toned underparts.
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
Mascarene Swiftlet
A small swiftlet (10-11 cm) endemic to Mauritius and Réunion in the western Indian Ocean. Dark brown plumage. Aerial insectivore, foraging over forest and agricultural areas. Colonial cave nester using echolocation for navigation. Population stable but geographically restricted.
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.