Marquesas Swiftlet vs Great Dusky Swift
Aerodramus ocistus verglichen mit Cypseloides senex
Side-by-Side Comparison
| Merkmal | Marquesas Swiftlet | Great Dusky Swift |
|---|---|---|
| Wissenschaftlicher Name | Aerodramus ocistus | Cypseloides senex |
| Ordnung | Caprimulgiformes | Caprimulgiformes |
| Familie | Apodidae | Apodidae |
| Erhaltungsstatus | Not Evaluated | Least Concern |
| Länge | — | — |
| Flügelspannweite | — | 33,8 cm (13.3 in) |
| Gewicht | 9,5 g (0.34 oz) | 83,0 g (2.93 oz) |
| Ernährung | Entirely aerial diet of tiny insects and spiders; forages in large flocks over open country … | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … |
| Gelegegröße | 1 | 1-2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Marquesas Swiftlet
High thin twittering; 'chip-chip' over Marquesas Islands; echolocation clicks in cave roosts; poorly documented; thin high-pitched calls typical of small Pacific swiftlets
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
Marquesas Swiftlet
Endemic to the Marquesas Islands of French Polynesia. Resident on major islands including Nuku Hiva and Hiva Oa. 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.
Erhaltungsstatus
Marquesas Swiftlet
Great Dusky Swift
How to Tell Them Apart
Marquesas Swiftlet
Small; dark brownish-grey upperparts; pale buff-grey rump band; underparts pale grey-white; forked tail; Marquesas Islands endemic in French Polynesia; closely related to Polynesian Swiftlet but isolated on its own archipelago.
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
Marquesas Swiftlet
A small swiftlet (10-11 cm) endemic to the Marquesas Islands of French Polynesia. Dark plumage. Aerial insectivore. Colonial cave nester. Population restricted to a few volcanic islands in the central Pacific. Classified as Endangered due to extremely limited range.
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.