Very small owl of tropical forest in the foothills of northeast Mexico where it is endemic. Favors forest canopy and is rarely seen, but sometimes hunts low at edges; active in the daytime. Most often detected by its distinctive tooting call, given at any time of day but mainly early and late: 13 slow-paced hollow hoots, repeated after a pause. Ferruginous Pygmy-Owl favors more open habitats, is seen much more frequently, and has pale streaks (not spots) on the crown and a very different tooting song.