The Whooping Motmot is the most widespread, familiar motmot of the lowlands of eastern Panama and northwestern South America, where its hooting call is a familiar sound in lowlands forests. Like many motmots, the Whooping Motmot has weak subterminal barbs on the central two rectrices. The Whooping Motmot is similar in many respects to several other allopatric species of motmots in the "Blue-crowned Motmot" complex, all of which formerly were classified as a single, highly variable species.
References:
Orzechowski, Sophia Catherine, and Thomas S. Schulenberg. 2011. Whooping Motmot (Momotus subrufescens), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=760856