The Black-tailed Trogon (Trogon melanurus) is a species of bird in the Trogonidae family. It includes the taxon mesurus, which sometimes is considered a separate species, the Ecuadorian Trogon (Trogon mesurus). It is found in humid forest in the Amazon Basin, north-western South America and adjacent Panama. The taxon mesurus is found in dry to deciduous and semi-humid forest and woodland in western Ecuador and far north-western Peru