Mariana Swiftlet vs Alpine Swift
Aerodramus bartschi compared with Tachymarptis melba
Side-by-Side Comparison
| Attribute | Mariana Swiftlet | Alpine Swift |
|---|---|---|
| Scientific Name | Aerodramus bartschi | Tachymarptis melba |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Apodidae | Apodidae |
| Conservation Status | Vulnerable | Least Concern |
| Length | — | — |
| Wingspan | 17.7 cm (7.0 in) | 43.9 cm (17.3 in) |
| Weight | 7.25 g (0.26 oz) | 97.5 g (3.44 oz) |
| Diet | Entirely airborne insectivore; feeds on minute flying insects and web-dispersing spiders over open habitats. | Aerial insectivore taking small flying insects and spiders; may forage at great heights following thermal … |
| Clutch Size | 1 | 1-4 |
| 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
Alpine Swift
Rapid series of short, clipped whistles; bright, clean notes delivered in quick succession with occasional doubled phrase.
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.
Alpine Swift
Breeds from southern Europe and North Africa east through Central Asia and the Himalayas to India. Migratory; winters in sub-Saharan Africa.
Conservation Status
Mariana Swiftlet
Alpine 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 …
Alpine Swift
Large; dark brown upperparts; white throat patch separated from white belly by dark brown breast band; brown flanks; bold tricoloured underpart pattern; one of Europe's largest swifts with distinctive white …
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.
Alpine Swift
A large swift (20-22 cm, wingspan 54-60 cm) with a white belly and throat contrasting with dark brown upperparts. Found from southern Europe and Africa to Central Asia. Aerial insectivore, foraging at great heights. Nests on cliff faces in large colonies. Powerful, fast flier.