Winter Owls

(This 925th Buffalo Sunday News column was first published on December 14, 2009.)

Snowy Owl photo by Jim Bailey

Local internet traffic suggests that we are in for a major incursion to this region from the far north of pine siskins, white-winged crossbills and snowy owls. Dozens of messages are reporting these species with one by Dave Tetlow of Rochester recording his count of 1785 crossbills, 2500 siskins, three Bohemian waxwings and a pine grosbeak.

Those who feed birds will wish to check their field guides to help them identify siskins and crossbills, but that won't be necessary for anyone to distinguish a big, nearly-all-white snowy owl.

Snowy owls are a circumpolar species, that is, their range includes not only North America but Europe and Asia as well. Not much of those continents, however. Their breeding range is along the farthest northern continental edges in treeless tundra country. A few are seen south of that range in winter, but every few years a major eruption occurs and more stray farther.

Ornithologists disagree about the cause of these movements. Some believe that they relate to the availability of food; others that they represent overcrowding after a good breeding season.

I invite observers to e-mail me describing sightings of any of these three species.

More important, I urge readers to watch for another owl species: the short-eared owl. Chuck Rosenburg of the state Department of Environmental Conservation is once again carrying out a study of this visitor to our region. The objective of the statewide study Rosenburg manages locally is to document short-eared owl wintering locations. The information collected will be used to establish a long-term population monitoring program. Please report observations (locations, numbers of owls, general behavior, etc.) to Rosenburg at 716-289-3122, to his email address, or to my own.

Each year a few groups of short-eared owls winter along the Lake Ontario plains, where it is thrilling to watch their evening flights over open fields. They are medium-sized owls, bigger than screech owls but smaller than great-horned and snowy owls. They are about the size of crows but, when flying, their 38-inch wingspread makes them appear much larger. During a winter evening, if you see a number of owls flying over open country like large bats, they are almost certainly short-ears. They often roost in daytime in nearby orchards or conifers.

Another objective of Rosenburg's study is to monitor short-eared owl movements to identify important foraging habitats and roost sites. The findings will ultimately be applied toward developing a conservation plan for this endangered species. As one part of the study, some owls are being trapped in mist nets and, after they are banded, small radio transmitters are placed on them so their movements can be tracked. Most transmitters are monitored using hand-held antennas, but a few others are followed by satellite tracking. The small, light-weight backpacks do not interfere with the birds' flying and foraging abilities.

Over the past two winters, six short-eared owls were captured in Niagara County and fitted with these radio transmitters. One of them provided a remarkable series of locations. This male owl was captured in Niagara County in February 2008 and tagged with a transmitter designed to send signals that reflect off a designated satellite to be picked up by a local receiver. By this means the owl's location was identified approximately every four days.

After spending about three weeks in the Niagara County study area, the owl traveled southwest past Erie, Pennsylvania and Cleveland, Ohio. Still farther west in Ohio, it spent about a month near New London. Then during the last week of April, the owl started its northward migration to Canada. In the period between April 23 and 26, it traveled roughly 400 miles from New London to a location north of Algonquin Provincial Park in Ontario. From there, it followed a somewhat circuitous route northeast an additional 800 miles until it almost reached the Atlantic coast in Labrador. It likely bred in that area as it spent the months of June through September in that same general area. Unfortunately, the transmitter signal was lost in late September suggesting that either the owl perished or the transmitter malfunctioned.

That entire itinerary was unexpected and it provided new insights into the life of this unusual species. Hopefully more data for comparison will be gathered this winter.-- Gerry Rising