This time of year is for the… owls.

Once again volunteers are getting ready to head out into the night to detect these mysterious nocturnal raptors. Thanks to a grant from the Department of Inland Fisheries and Wildlife, Maine Audubon is able to continue these Cooperative Owl Surveys, begun in the winter of 2002. This marks the third year of this venture.

The previous two years of the survey were a great success. Hardy (or foolhardy?) souls went out at all hours of the night during January, February, March, and April – when owls are breeding – to play recordings of owl calls, waiting in the freezing darkness for any reply. Any vocalizations (or lack of), along with ambient conditions (temperature, cloud cover, precipitation, snow cover, wind speed, noise pollution) were then carefully recorded. The results of the surveys produced some surprises, as we were to find during a recap and slideshow at Fields Pond Audubon Center in Holden.

More than 200 volunteers conducted a total of 600 surveys over the two years, finding a total of 1,476 owls. Of these, approximately 45 percent were barred owls, 35 percent were saw-whet owls, and 20 percent were great horned owls. This was not unexpected, since these are Maine’s three most common owls. The surprise came with the discovery of several eastern screech owls, leading biologists to conclude that these small owls are more prominent in Maine than was previously thought.

The eastern screech owl’s range has historically been thought to reach only as far as New Hampshire, with the occasional rare report in southern Maine. Survey volunteers proved otherwise; up to 10 of these owls were reported among York and Cumberland counties, up to Monroe, Winterport, and Dover-Foxcroft.

When listening for these owls, Nature Center director Judy Markowsky stressed it’s important to keep in mind that their name is something of a misnomer. Barred and great horned owls can produce screeching sounds as well as their usual “signature” vocalizations.

The screech owl doesn’t exactly screech; one variation of its call is a mournful, descending “whinny,” which is eerie and certainly startling – sounding like a “little whinny of a tiny tin horse,” according to Markowsky. The other variation is a long, whistled tremolo on one pitch, which sounds much more mellow and pleasing than its maniacal “whinny.” Still, neither one of these calls sounds very owl-like.

There were a few reports of Maine’s two other uncommon owls. Short-eared owls were found in Carmel, Levant, and Bangor, but so far, “I believe they’ve never been confirmed nesting in Maine,” Markowsky said. “They ought to be nesting here,” she continued, as there is an abundance of their preferred habitat: marshes and open, wet meadows.

Long-eared owls, which are very shy forest denizens, were only reported twice during the surveys.

The remainder of the evening passed pleasantly as those in attendance shared their stories about participating in the survey and about owls in general. The conclusion of two years’ worth of surveys suggested that volunteers need only go out once, in March; previously, participants conducted three surveys each winter, going out at various times of the night. This helped biologists determine that the best time to hear owls is after midnight, when there is less noise pollution to interfere with detection.

If you’d like to sign up as a volunteer, contact Susan Gallo at 207-781-2330, ext. 216.

Chris Corio, a volunteer at Fields Pond Audubon Center in Holden, can be reached at fieldspond@juno.com