Pacific Swallow
Hirundo javanica
This species is a small swallow at 13 cm (5.1 in) in length. It has a blue-black back and crown with browner wings and tail, a red face and throat, and dusky underparts. It differs from the barn swallow and the closely related welcome swallow in its shorter and less forked tail.
ID text from Wikipedia, CC BY-SA 4.0
Wire-tailed Swallow
Hirundo smithii
The wire-tailed swallow is a small swallow, measuring 18 cm (7.1 in) in length. It has bright blue upperparts, bright white underparts and a chestnut cap. Immature birds lack tail wires, and have dull brown (rather than chestnut) caps. The species is named for the very long filamentous outermost tail feathers, which trail behind like two wires. The sexes are similar in appearance, but the female has shorter "wires". Juveniles have a brown crown, back and tail. The Asian form, H. s. filifera, is larger and longer-tailed than the abundant African H. s. smithii.
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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