Wikipedia:Today's featured article/October 6, 2018

The tree swallow is a migratory bird of the family Hirundinidae. Found in the Americas, it was first described in 1807 by French ornithologist Louis Vieillot as Hirundo bicolor. It has since been moved to the genus Tachycineta, where its phylogenetic placement is in debate. It has glossy blue-green upperparts, with the exception of the blackish wings and tail, and white underparts. The bill is black, the eyes are dark brown, and the legs and feet are pale brown. The tree swallow breeds in the US and Canada. It winters in the West Indies and from the southern US coasts to Panama and the northwestern coast of South America. It nests in isolated pairs or loose groups, in both natural and artificial cavities. Breeding can start as soon as early May (although this date is advancing because of climate change), and can end as late as July. The species is generally socially monogamous, with high levels of extra-pair paternity. An aerial insectivore, the tree swallow forages alone and in groups.