Mariana Swiftlet vs White-chested Swift
Aerodramus bartschi compared with Cypseloides lemosi
Side-by-Side Comparison
| Attribute | Mariana Swiftlet | White-chested Swift |
|---|---|---|
| Scientific Name | Aerodramus bartschi | Cypseloides lemosi |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Vulnerable | Least Concern |
| Length | — | — |
| Wingspan | 17.7 cm (7.0 in) | 30.0 cm (11.8 in) |
| Weight | 7.25 g (0.26 oz) | 28.400000000000002 g (1.00 oz) |
| Diet | Entirely airborne insectivore; feeds on minute flying insects and web-dispersing spiders over open habitats. | Obligate aerial forager catching small flies, aphids, winged termites, and airborne spiders on the wing. |
| Clutch Size | 1 | -- |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Mariana Swiftlet
Very high, thin twittering; tiny and high-pitched; 'tsit-tsit' over Guam and Saipan; audible echolocation clicks in cave roosts; endangered; vocal mainly near nesting caves
White-chested Swift
High, thin twittering; soft 'tsit' calls in flight; calls over Colombian waterfalls; very poorly known; thin, reedy contact notes; one of most rarely documented swifts
Geographic Range & Migration
Mariana Swiftlet
Endemic to the Mariana Islands (Guam, Saipan, and adjacent islands). Resident in forested areas; nests in limestone caves. Endangered on Guam.
White-chested Swift
Known from Colombia and adjacent Ecuador. One of the world's rarest swifts; recorded at waterfalls in humid forest foothills at 500–1,200 m.
Conservation Status
Mariana Swiftlet
White-chested Swift
How to Tell Them Apart
Mariana Swiftlet
Tiny; dark brownish-black upperparts; pale grey-buff rump band; underparts pale whitish-grey; forked tail; Mariana Islands endemic and vulnerable; very small for the genus with concolorous brownish tone and subdued rump …
White-chested Swift
Black upperparts and wings; distinctive large white chest patch contrasting sharply with black throat and belly; white confined to central breast; Colombian endemic with unique bold bicoloured plumage unlike any …
About These Birds
Mariana Swiftlet
A small swiftlet (10-11 cm) endemic to the Mariana Islands of the western Pacific (Guam, Saipan, Rota, Tinian). Dark brown plumage. Aerial insectivore. Colonial cave nester using echolocation. Population severely declined on Guam due to the brown tree snake.
White-chested Swift
A medium-sized swift (14-15 cm) endemic to the upper Cauca Valley of Colombia. Sooty-black plumage with a white breast patch. Aerial insectivore of subtropical forests. Classified as Endangered due to extremely restricted range and ongoing habitat loss.