|Ferruginous pygmy owl|
|Cactus ferruginous pygmy owl|
The ferruginous pygmy owl (Glaucidium brasilianum) is a small owl that breeds in south-central Arizona and southern Texas in the United States, south through Mexico and Central America, to South America into Bolivia, Paraguay and Argentina.
In Central America and South America, it is the most widely distributed pygmy owl and is probably one of the most numerous owl species in those areas. It is found in a wide range of semi-open wooded habitats in these areas.
Trinidad, as well as other localities, have endemic subspecies of the Glaucidium brasilianum owl. Recent genetics work has found substantial differences in ferruginous pygmy owls from different regions and members of the northern ridgwayi group are sometimes considered a separate species, the Ridgway’s pygmy-owl (Glaucidium ridgwayi).
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).
The ferruginous pygmy owl is small, typically 15 cm (5.9 in), and stocky with disproportionately large feet and talons. The crown has elongated white/buff streaks, the wing coverts have white spots, and the underparts are heavily streaked white. There are prominent white supercilia above the facial disc. There are dark two spots on the nape, often termed “false eyes” by birders.
Otherwise, its overall color is highly variable, ranging from grey-brown with a black-and-white barred tail to rich rufous with a uniform rufous tail. Sexes are similar with females slightly larger and often more reddish.
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 the pygmy owls.
Breeding and incubation
The Glaucidium brasilianum mating season is from late winter to early spring. It is a cavity nesting bird (tree and columnar cactus cavities), laying 1-7 white eggs. Incubation is 28 days, with 27–30 days to fledging.
The northernmost subspecies, G. b. cactorum, commonly called the cactus ferruginous pygmy owl, was a listed Endangered species under the U.S. Endangered Species Act. This protected it in south-central Arizona from loss of habitat and buffel grass fires. Buffel grass catches fire very easy, which spreads to cacti, burning the owl’s primary habitat.
Its range extends over the border into Sonora, Mexico. Glaucidium brasilianum was delisted in 2006.