The most strictly nocturnal of all North American owls, screech owls spend their days roosting in old woodpecker holes or tree cavities. At night, the short, stocky owl -- no bigger than an eggplant -- is more often heard, than seen. The American Ornithological Union recognizes three species of screech owl, all members of the genus Megascops. At least one of these species resides in each of the lower 48 states.
Whistled Whinny and Trill
A nonmigratory bird, Eastern screech owls take up residence every state from the Great Plains eastward. The western edge of their range includes eastern Montana, Wyoming and Colorado, as well as most of Nebraska, Kansas, Oklahoma and Texas. The owl's darkly banded, white-specked plumage resembles tree bark, providing excellent camouflage. Eastern screech owls can be mostly red or mostly gray. The red or rufous color morph is more common in the mideastern states, whereas the gray color morph is more common in the Great Plans. Both colors can occur within the same family. Distinguishing the owl from its western cousin, the eastern screech owl's primary call is a strongly descending, whistling whinny or an even-pitched trill. The shorter whinny is used to defend territories, while the longer trill is used by pairs to communicate.
Follow the Bouncing Ball
Save for its darker bill, the western screech owl is virtually identical to its eastern cousin. The western screech-owl is widespread, but not common, across the western states, with a range that extends to the western edges of Montana, Wyoming, Colorado and Texas. Only at the Pecos River in the Texas panhandle, do the ranges of the western and eastern species overlap. While there are subtle physical differences between the two, the key to distinguishing the western and eastern screech-owls is through their markedly different songs. The western screech-owl's call is comprised of a series of short whistles that accelerate like a bouncing ball.
At higher elevations in southeast Arizona and southwest New Mexico, the elusive whiskered screech-owl can be heard issuing a song of four to eight small toots, higher in the middle and slowing at the end. An alternate, morse-code like call may also be heard; one that resembles "pidu po po pidu po po." The smallest of the three species, the whiskered screech-owl has smaller feet, large yellow eyes, a greenish-yellow beak and more prominent whiskers, suggesting it preys primarily on insects rather than rodents or other small mammals. The small, United States' population of whiskered screech-owl comprises only 5 percent of the total population, the remainder of which occurs in Mexico and Central America.
Management and Conservation
Eastern and western screech-owls are considered widespread and common throughout their range. Neither species has been greatly affected by human development, as they appear tolerant of human activity. In fact, both species will utilize urban parks, bird baths and human-fabricated nesting boxes. The primary threat to screech owls appears to be degradation or loss of wooded habitats along the edges of rivers or streams. In New Mexico, the whiskered screech-owl is listed as threatened by the state wildlife agency, though the state's population appears to be steady if not slightly increasing.
- NatureServe Explorer: Screech Owl
- The Cooper Ornithological Society: Nest-Site Selection by Eastern Screech-Owls in Central Kentucky
- The Cornell Lab of Ornithology - All About Birds: Eastern Screech-Owl
- United States Forest Service: Western Screech-Owl
- The Cornell School of Ornithology - Neotropical Birds: Megascops Trichopsis
- New Mexico Avian Conservation Partners: Whiskered Screech Owl
- Jupiterimages/Photos.com/Getty Images