Fernando Po Swift vs Great Dusky Swift
Apus sladeniae comparado con Cypseloides senex
Side-by-Side Comparison
| Atributo | Fernando Po Swift | Great Dusky Swift |
|---|---|---|
| Nombre científico | Apus sladeniae | Cypseloides senex |
| Orden | Caprimulgiformes | Caprimulgiformes |
| Familia | Apodidae | Apodidae |
| Estado de conservación | Data Deficient | Least Concern |
| Longitud | — | — |
| Envergadura | 35,4 cm (13.9 in) | 33,8 cm (13.3 in) |
| Peso | 42,0 g (1.48 oz) | 83,0 g (2.93 oz) |
| Dieta | Aerial insectivore relying entirely on flying insects (midges, gnats, small beetles) and airborne spiders. | Feeds on aerial plankton of tiny insects and spiders; entire diet captured during non-stop aerial … |
| Tamaño de la puesta | 1-2 | 1-2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Fernando Po Swift
Deep, resonant wingbeat audible alongside soft chips; quiet churring call barely distinguishable from surrounding ambient sounds.
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
Fernando Po Swift
Found on Bioko Island in the Gulf of Guinea and adjacent Cameroon highlands. Restricted to mountain forests and highland areas.
Great Dusky Swift
Found in eastern South America from Venezuela and the Guianas south to Bolivia and Paraguay. Resident near rocky cliffs and waterfalls.
Estado de conservación
Fernando Po Swift
Great Dusky Swift
How to Tell Them Apart
Fernando Po Swift
Dark sooty-brown overall; pale greyish throat and chin patch; underparts slightly paler; broadly similar to African Swift; data-deficient Bioko Island endemic; plumage details poorly documented from limited specimens.
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
Fernando Po Swift
A medium-sized swift (14-15 cm) found on the island of Bioko (formerly Fernando Po) in the Gulf of Guinea, Equatorial Guinea. Dark plumage. Aerial insectivore. A poorly known, range-restricted species limited to the volcanic island. Very 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.