Wikipedia:Today's featured article/May 8, 2017

The white-rumped swallow (Tachycineta leucorrhoa) is a species of bird, the only one in its genus, in the family Hirundinidae. First described and given its scientific name by French ornithologist Louis Vieillot in 1817, it has no known population variations. It is black from the eyes to the nostrils, with a white streak just above. The ear coverts, tail, and wings are black, with white tips on the wings. The rest of the upperparts are a glossy blue. Its underparts and underwing-coverts are white, in addition to the rump, as the name suggests. It usually builds its nest in holes in trees or dead snags, and sometimes under eaves or in holes in fence posts. This swallow is found in Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay. Its natural habitats are dry savanna, pastureland, the edge of forests, and subtropical or tropical seasonally wet or flooded lowland grassland. It is classified as a species of least concern by the International Union for Conservation of Nature. Its population is increasing, partly because of the increase in availability of man-made structures suitable for nest sites.