The Eastern Screech-Owl (Megascops asio) is one of our more common birds. This fact may come as a surprise, since, like most owls, this species is seldom seen without a special effort made to find it. Its nocturnal habits and reticent nature conceal it from a mostly diurnal, relatively unobservant species such as our own.
This is a small owl, slightly smaller than a Rock Pigeon (Columba livia). It has two ear tufts, piercing yellow eyes, and a small, sharp bill. The plumage of most individuals in this area is basically gray on the upperparts and white on the underparts, heavily overlaid in both areas with vertical black streaking combined with very thin horizontal barring. There is also scattered white spotting on the back and near the bend of the wing. Some birds belong to the less common red color morph of this species, where the gray, and much of the black streaking and barring on the underparts is replaced by a bright rufous color. These red morph birds are less cold-hardy than gray ones, and thus gray birds are more common in northern parts of the bird’s range such as southern New York.
Screech-Owls are more often heard than seen. There are two main calls, neither of which could fairly be described as a screech. One is a soft, low, surging trill, given throughout the year. The other is similar in quality, but starts higher in pitch and ends lower, a sound rather reminiscent of a horse whinnying. This call is mostly given in the breeding season. Young birds begging for food from their parents give a raspy, descending “wshhhhh.” The primary prey is small mammals caught by swooping down from a perch, especially white-footed mice (Peromyscus leucopus) and voles (Microtus), but insects, birds, reptiles, and amphibians are also taken on occasion. In fact, the nestling stage in the development of the young seems timed to coincide with spring songbird migration, when smaller birds become a more important part of the diet.
These owls are permanent residents in our area and tend to prefer open areas near water with larger deciduous trees: the edges of woods, open woods, and even suburban yards. They nest and roost in natural cavities in trees, old woodpecker nest or roost holes, and sometimes appropriately sized birdhouses. If the cavity is oriented the right way, these owls will often perch at the opening of the cavity and bask with closed eyes in the sun, especially at the colder times of the year.
Leave those snags and dead trees, if they don’t pose a safety hazard, in place. Many trees will stand tall for years and years after they die, and provide critical nesting cavities. You can also put up a Screech-owl box, too.