The Ferruginous Pygmy Owl (Glaucidium brasilianum) is a small owl that breeds in south-central Arizona in the USA, south through to Mexico, Central America and South America to Bolivia and Argentina. Trinidad, as well as other localities, have endemic subspecies of the owl. The Trinidad version is more rufous above than the continental forms. Recent genetics work has found substantial differences in Ferruginous Pygmy Owls from different regions.
In the southern portion of its range, the Ferruginous Pygmy Owl is a somewhat common bird in open woodland. It is a cavity nesting bird (tree and columnar cactus cavities), laying 3-5 white eggs. Incubation is 28 days, with 27-30 days to fledging.
The Ferruginous Pygmy Owl is small, typically 15 cm (6 in), and stocky with disproportionately large talons. The upperparts are brown, heavily spotted and/or streaked with white on the crown and wing coverts. The underparts are white, streaked with brown. There are prominent white supercilia above the facial disc. There are two eyespots on the nape. The tail is barred brown and black. Sexes are similar with females slightly larger and more reddish, especially on the brown in the tail. The flight is low to the ground and rapid with long swoops.
This species is crepuscular (active at dawn and dusk), and often hunts by day. It can be readily located by the small birds that mob it while it is perched in a tree (up to 40 birds of 11 species have been recorded mobbing one owl). It hunts a variety of birds, lizards, mammals, and insects. The call is a whistled hoo-hoo-hoo-hoo, usually in E flat. It is easily imitated, and is used by birdwatchers to attract small birds intent on mobbing and other pygmy owls.
The northernmost Cactus Ferruginous Pygmy-owl subspecies was listed Endangered under the ESA, referring to its range in the south-central portion of Arizona in the USA, where its range extended over the border from Sonora, Mexico. It was delisted in 2006.