Ferruginous Pygmy-Owl (Glaucidium brasilianum): Mochuelo común; Chevêchette brune; Brasilsperlingskauz
The coffee fields at Aquiares continue to bring unexpected bird sightings. A couple of days ago Milena and Sean Beer located a Ferruginous Pygmy-Owl in a poró tree. It had been chased there by a pair of Masked Tityras (Tityra semifasciata).
Our other pygmy-owl species are the Costa Rican Pygmy-Owl (Glaucidium costaricanum) and the Central American Pygmy-Owl (Glaucidium griseiceps). The latter is a lowland forest species rarely seen and not reported close to Turrialba. It is found only on the Caribbean side of the country, with the nearest, very sparse sightings on the Rio Pacuare and at the Las Brisas reserve near La Alegría.
From November 2015 to February 2016 the highland species costaricanum appeared in my garden on several occasions. More than once this happened during the day when it was mobbed by almost the full range of my garden songbirds.
Like griseiceps, this species has spots on the head, as shown in John’s excellent photo from Los Bajos del Volcán high on the Turrialba Volcano slope, while the Ferruginous Pygmy-Owl’s head is streaked, as seen further below. Call notes of all three species are a series of toots that are perhaps not always safely distinguishable, so range and habitat are the best guides if no close-up view or photograph can be obtained. Fortunately, after locating this individual Milena and Sean then brought John to the scene, where the owl had remained, and he was able to obtain several good photographs.
There are many sightings of the Ferruginous Pygmy-Owl in Costa Rica’s Central Valley, even at higher elevations, but there are virtually no reports from the Irazú and Turrialba volcanoes, and Turrialba area sightings are exclusively from lower areas. Tour guides often locate the species near the lake at CATIE, for example.
On the Caribbean slope there are very few sightings of the species at all. A pygmy-owl seen at great distance was identified by its repeated call as a Ferruginous by several observers at Parque Nacional Barbilla. This was during my first visit to this beautiful area back in October 2010. Given the elevation of the sighting (650 m) and the presence of other, more experienced observers, I am now (revision, July 2020) inclined to accept this identification.
Sadly, I myself have to date been unable safely and independently to identify either the Central American or the Ferruginous Pygmy-Owl. The environs of the coffee town of Aquiares continue to turn up unlikely species. I can hardly wait for my next opportunity for a return visit.