The Mangrove Swallow bears a strong resemblance to the Violet-green Swallow and the Tree Swallow. One notable difference is its white rump which can be seen in flight. It can be found near water in lower elevations of Mexico and Central America.
This swallow was photographed from a bridge overlooking the Papaloapan River near Tuxtepec, in the state of Oaxaca, Mexico. (click or tap to enlarge)