Aegolius

Aegolius is a genus of small true owls. The genus name is from Latin; aegolius is a type of screech owl thought to be a bird of ill omen.

Three of the extant species are restricted to the New World, but the boreal owl has a circumpolar range through North America, Eurasia, the Alps, and the Rockies.

The species are:

Boreal owl or Tengmalm’s owl, Aegolius funereus

Northern saw-whet owl, Aegolius acadicus

Unspotted saw-whet owl, Aegolius ridgwayi

Buff-fronted owl, Aegolius harrisii

Bermuda saw-whet owl, Aegolius gradyi (extinct)

Aegolius martae (extinct)

These are essentially nocturnal woodland owls of temperate or colder climates; the two northern species breed in North America’s coniferous forests, and the unspotted saw-whet owl and buff-fronted owl (Central and South America, respectively) are species of mountain, cloud, or oak forests.

These are mainly resident birds, but the northern species at least sometimes move south or to lower altitudes in autumn. The movements are difficult to monitor due to the problems of detecting these nocturnal owls outside the breeding season, when they are not calling.

Aegolius owls are small, dumpy, short-tailed, and broad-winged, with large, round facial discs. The species varies from 18–27 cm in length.

These owls take mainly rodents and other small mammals as their prey, but also feed on birds, bats, insects, and other invertebrates according to what is available.

The Aegolius owls are dark brown or black above, and whitish or buff below, marked with streaks or spots in the two northern forms. The head is large, with yellow eyes and a well-defined facial disc. The flight is strong, agile, and direct.

Aegolius owls breed in tree holes, laying several eggs. They have repetitive whistling calls in the breeding season.

Pygmy owl

Pygmy owls are members of the genus Glaucidium. They belong to the typical owl family, Strigidae. The genus consists of about 26 to 35 species distributed worldwide. The exact number of species is somewhat disputed.
These are mostly small owls, and some of the species are called “owlets”. Most pygmy owl species are nocturnal and hunt mainly large insects and other small prey.
Glaucidium forms a paraphyletic group with Surnia.

Scops owl

Scops owls are typical owls (family Strigidae) mostly belonging to the genus Otus. Approximately 45 living species are known, but new ones are frequently recognized and unknown ones are still being discovered every few years or so, especially in Indonesia. For most of the 20th century, this genus included the American screech owls, which are now again separated in Megascops based on a range of behavioral, biogeographical, morphological and DNA sequence data. Otus is the largest genus of owls in terms of number of species.
Scops owls in the modern sense are restricted to the Old World. A single North American species, the flammulated owl, was provisionally placed in Otus and has now been moved to its own monotypic genus. See below for details.
As usual for owls, female scops owls are usually larger than the males of their species, with owls of both sexes being compact in size and shape. All of the birds in this genus are small and agile. Scops owls are colored in various brownish hues, sometimes with a lighter underside and/or face, which helps to camouflage them against the bark of trees. Some are polymorphic, occurring in a greyish- and a reddish-brown morph.
Scops owls are typical owls (family Strigidae) mostly belonging to the genus Otus. Approximately 45 living species are known, but new ones are frequently recognized and unknown ones are still being discovered every few years or so, especially in Indonesia. For most of the 20th century, this genus included the American screech owls, which are now again separated in Megascops based on a range of behavioral, biogeographical, morphological and DNA sequence data. Otus is the largest genus of owls in terms of number of species.
Scops owls in the modern sense are restricted to the Old World. A single North American species, the flammulated owl, was provisionally placed in Otus and has now been moved to its own monotypic genus. See below for details.
As usual for owls, female scops owls are usually larger than the males of their species, with owls of both sexes being compact in size and shape. All of the birds in this genus are small and agile. Scops owls are colored in various brownish hues, sometimes with a lighter underside and/or face, which helps to camouflage them against the bark of trees. Some are polymorphic, occurring in a greyish- and a reddish-brown morph.

Northern saw-whet owl

The northern saw-whet owl(Aegolius acadicus) is a small owl native to North America. Saw-whet owls are one of the smallest owl species in North America. They can be found in dense thickets or conifers, often at eye level, although they can be found around 20 feet up. Saw-whets are often in danger of being preyed upon by larger owls and raptors. Saw-whet owls are also migratory birds without any strict pattern.

Great grey owl

The great grey owl or great gray owl (Strix nebulosa) is a very large owl, documented as the world’s largest species of owl by length. It is distributed across the Northern Hemisphere, and it is the only species in the genus Strix found in both Eastern and Western Hemispheres. In some areas it is also called Phantom of the North, cinereous owl, spectral owl, Lapland owl, spruce owl, bearded owl, and sooty owl.

Eastern screech owl

The eastern screech owl or eastern screech-owl (Megascops asio) is a small owl that is relatively common in Eastern North America, from Mexico to Canada. This species is native to most wooded environments of its distribution, and more so than any other owl in its range, has adapted well to manmade development, although it frequently avoids detection due to its strictly nocturnal habits.

The eastern screech owl or eastern screech-owl (Megascops asio) is a small owl that is relatively common in Eastern North America, from Mexico to Canada. This species is native to most wooded environments of its distribution, and more so than any other owl in its range, has adapted well to manmade development, although it frequently avoids detection due to its strictly nocturnal habits.