The Carlisle Mosquito Online

Friday, March 7, 2008

Features


Eastern Screech Owl

(Photo by Tom Brownrigg)

I had originally intended the owl for publication last Friday, Leap Day, even though it was a bit of a leap to make it seem topical. The owl did its best to celebrate the occasion by spending the whole day sleeping. Turns out it is more connected to the process of choosing presidential candidates, especially this year when “hope” has a starring role in the rhetoric. Senator Obama has been eloquent on the topic, but we already knew from Emily Dickinson that “hope is the thing with feathers that perches in the soul.” It’s just a small leap from there to a “thing with feathers that perches in the hole” of an old tree.

When and where seen. Steve Spang first noticed the owl one day early in February on his property on Fiske Street. He and his wife Roberta now see it almost every day as it roosts on the edge of its hole about 20 feet above the ground. They have become quite attached to “their” owl. It is there in the mornings until about 9 a.m., and it reappears in the afternoons about 3 p.m. This regular schedule made photo opportunities more manageable – not easy but at least possible.

Tom Brownrigg’s photo shows the owl in its typical roosting posture, with its ear tufts raised, its feathers fluffed up, and its eyes closed to slits. The owl has been there in rain, snow and sun, although it did not appear for a few days when it was uncommonly cold and has taken a few days off since Leap Day.

Screeching.The Eastern Screech Owl doesn’t screech. It makes two different calls, neither of which are the tu-wit tu-woo hoots that we associate with owls. One of the calls is described by David Sibley as “a strongly descending whinny with a husky falsetto quality reminiscent of a whinnying horse.” The other is a single-pitch toad-like trill which lasts about three seconds.

Name. The Eastern Screech Owl may be rising above its unfortunate “screech” name, and while it is not a recording artist, it is the bird formerly known as Otus asio – a source of confusion since the Long-eared Owl is Asio otus. (These back-to-front names are troublesome – just ask our governor, or Patrick Deval, the movie director.) Anyway, DNA tests have led to the screech owls being assigned a genus of their own, Megascops, with the Eastern Screech Owl being Megascops asio. Mega- meaning large, the new genus name means large scops. Scops owls are old-world owls that are still in the genus Otus. (Did you know that Ron Weasley’s owl, Pigwidgeon, is a scops owl?)

Distinguishing characteristics.This is a small owl, about eight inches long. It has the same kind of “horns” or ear tufts that give the Great Horned Owl its name. The ear tufts are usually in the raised position, while perching, as an aid to camouflage.

Eastern Screech Owls come in two color morphs – red and gray. Steve’s owl is of the gray variety and is streaked with brown and black. It has dark vertical lines down its pale front, and with its large yellow eyes closed, it is hard to spot against the gray tree bark. It is the smallest owl with ear tufts in New England.

Behavior. This bird is a cavity nester that usually chooses a natural cavity in a deciduous tree at least six feet above the ground. It is small enough that it is able to reuse nest holes from Northern Flickers, and it sometimes returns to its own nest site from a previous year. It will also nest in man-made bird houses.

Its diet is more varied than that of some other owls. In addition to mice and voles, it eats larger rodents like chipmunks and also night-flying insects and even birds. It hunts at night in open woodlands or at the edge of open fields using a sit-and-wait strategy to locate prey.

Steve’s owl lives right across from some large open fields at the edge of the Cranberry Bog. Eastern Screech Owls tend to avoid the denser forest habitats which are favored by one of its predators, the Great Horned Owl.

References. Sibley Guide to Birds by David Allen Sibley; Sibley Guide to Bird Life and Behavior by David Allen Sibley; Cornell Lab of Ornithology at


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