Unspotted Saw-whet Owl

The Unspotted Saw-whet Owl, Aegolius ridgwayi, is a diminutive and elusive bird of prey, part of the family Strigidae. It measures a modest 18 to 21.5 cm in length and tips the scales at approximately 80 to 90 grams. The plumage is a uniform sepia brown across the upperparts, throat, and upper breast, transitioning to a cinnamon buff on the lower breast and belly. The tail is a darker shade of brown, while the wings adopt a grayer hue. A narrow white border frames its brown facial disk, and the lores, chin, and "eyebrows" are of a lighter, whitish color. The eyes of this owl are a striking yellow.

Identification Tips

When attempting to identify the Unspotted Saw-whet Owl, look for its small size, brown plumage with no spots, and yellow eyes. The white accents on the face and the cinnamon buff underparts are also key characteristics. The two additional subspecies, A. r. tacanensis and A. r. rostratus, exhibit only minor variations from the nominate form.

Habitat

This species favors humid temperate montane forests, including oak forests, cloud forests, and pine-oak forests. It is typically found in the forest canopy but may venture into more open areas near forest edges.

Distribution

The Unspotted Saw-whet Owl's range extends from central Costa Rica through western Panama, with subspecies A. r. tacanensis located in Chiapas, Mexico, and A. r. rostratus in Guatemala and northwestern El Salvador.

Behaviour

Nocturnal and often solitary except during breeding season, the Unspotted Saw-whet Owl is thought to be territorial. Its flight is characterized as agile and fluttery, with rapid wingbeats.

Song & Calls

The male's territorial call is a rhythmic "hoo hoo hoo…" repeated over a few seconds, while females emit a high, hissing "ssirr." Both sexes can produce a loud shriek or a shrill, short chipper. Their calls can be easily mistaken for the song of Anotheca tree frogs.

Breeding

Details on the breeding habits of the Unspotted Saw-whet Owl are scarce. The breeding season seems to span from March to July, with nesting in cavities and a clutch likely consisting of five or six eggs.

Diet and Feeding

While the specifics of its diet are not well documented, it is believed that small mammals such as shrews and rodents form the bulk of its diet, supplemented by birds and bats.

Conservation status

The IUCN has classified the Unspotted Saw-whet Owl as Least Concern, with a population that is presumed stable. However, habitat disturbance due to deforestation is a concern, particularly at lower elevations. In Mexico, the species is considered at risk of extinction.