Білозорка мангрова Tachycineta albilinea

Small swallow of tropical lowlands. Usually near water, from mangroves and coastal lagoons to rivers well inland; mainly in small groups, often mixed with other species of swallows. In its range, the big white rump patch is distinctive. Adult is metallic blue above with small white chevron across base of bill; gleaming white below. Juvenile has dusky gray-brown upperparts with white rump, looks like adult by early winter.