ズアカコシアカツバメ 対 コズアカコシアカツバメ

The most reliable field mark between Greater and Lesser Striped Swallow is the rump color: Greater has a pale orange rump, while Lesser shows a deeper red rump. Underpart streaking is also key—Lesser has heavier, darker streaks below, while Greater’s are finer and less pronounced. Head color differs subtly: Greater’s crown and nape are chestnut, Lesser’s are a brighter rufous-chestnut. Juveniles of both are duller and browner, but the same contrasts apply. Both species have long outer tail feathers, but Greater is distinctly larger and prefers more open, hilly habitats.

1. Rump color: Look for the rump in flight or when perched—Greater’s is pale orange, Lesser’s is a deeper, richer red. This is often the quickest field mark.
2. Underpart streaking: Lesser has much heavier and darker streaks on the breast and belly, while Greater’s are finer and less pronounced. This is visible in both perched and flying birds, but especially useful when viewing from below.
3. Head color: Greater’s crown, nape, and sides of the head are chestnut; Lesser’s are a brighter, more rufous-chestnut. This can be subtle and affected by lighting, but is useful at close range.
4. Underwing coverts: Greater’s are creamy white, Lesser’s are tawny. This is a subtle mark, best seen in good light or photos.
5. Tail length and shape: Both species have long, deeply forked tails with very long outer feathers, slightly longer in males. Greater’s tail is proportionally longer due to its larger size, but this is not always obvious unless comparing side by side.
6. Juvenile plumage: Juveniles of both are duller and browner, but the rump and streaking differences persist. Juvenile Lesser still shows heavier streaking and a deeper red rump.
7. Size: Greater is larger (18–20 cm) than Lesser (15–19 cm), but this can be hard to judge unless both are together.
8. Flight style: Greater’s flight is slow and buoyant; Lesser’s is more erratic. This is a supporting mark, not diagnostic on its own.
9. Habitat: Greater prefers open, hilly or mountainous areas and avoids woodland; Lesser can be found in a wider range of open habitats, sometimes less open than Greater prefers.
10. Vocalizations: Listen for Greater’s twittering 'chissick' versus Lesser’s nasal 'zeh zeh zeh.' This is a subtle aid, best used with other marks.
11. Ear coverts: Lesser’s are rufous, Greater’s are buffy. This is a fine detail, rarely diagnostic in the field but may help in close views or photos.
12. Context: In southern Africa, both species may be present, but Greater is more likely in open, hilly country, while Lesser is more widespread and can be found in a broader range of open habitats.
13. Nest sites: Both use man-made structures, so nest location alone does not separate them.
14. Pitfalls: Lighting can affect perception of rump and head color; always check multiple marks. Juveniles are especially tricky—focus on rump color and underpart streaking.
15. Subspecies variation: Lesser has several subspecies with variable streaking, but all have heavier streaks than Greater.

Greater Striped Swallow is the larger species, measuring 18–20 cm in length, compared to Lesser’s 15–19 cm. This size difference is subtle in the field but can be apparent with direct comparison or in mixed flocks. Both have long, deeply forked tails, with males of both species showing slightly longer outer tail feathers. Bill and wing proportions are similar and not reliably diagnostic at a distance.

• Juveniles/immatures: Both species’ juveniles are duller and browner overall, with less contrast and shorter outer tail feathers than adults. The same rump and underpart streaking differences apply: Greater’s rump remains pale orange, Lesser’s is deeper red; Lesser’s streaking below is always heavier and darker.
• Adults: Greater has dark blue upperparts, a pale orange rump, and a chestnut crown/nape/sides of head. Underparts and underwing coverts are creamy white with fine dark streaking. Lesser has dark blue upperparts, a red rump, and a brighter rufous-chestnut crown/nape/sides of head. Underparts are white with heavy, dark streaking, and underwing coverts are tawny. Both have blackish-brown upper and underwing flight feathers and a long, blackish forked tail.

Both species feed mainly on flying insects, sometimes taking small fruits. Greater Striped Swallow’s flight is described as slow and buoyant, while Lesser’s is more erratic. Both are comfortable around human habitation and readily use man-made structures for nesting. Both species are unafraid of humans and may be seen perching on wires or flying low over open ground.

Greater Striped Swallow favors dry, open country—especially grassland, hills, and mountains—and avoids wooded areas. It is often found near human habitation and has benefited from artificial nest sites. Lesser Striped Swallow is more widespread across Sub-Saharan Africa and is relatively sedentary, but also uses open country and man-made structures. Lesser is more likely to be found in less open habitats compared to Greater, but both overlap broadly in southern Africa.

Greater Striped Swallow gives a twittering 'chissick' call. Lesser Striped Swallow’s call is a nasal 'zeh zeh zeh zeh zeh.' These vocal differences are subtle and may be hard to separate in the field without experience, but can support identification if heard clearly.