TEHKUMMAH—Bird Studies Canada was looking for Island volunteers with a keen sense of hearing to participate in an annual nocturnal owl study last month. Christa Paquette of Sudbury responded and late in April spent a cool evening listening for owls and other nocturnal sounds along a 20 km stretch of Government Road near Providence Bay.
Armed with a clipboard, a CD and a Bluetooth speaker, Ms. Paquette arrived at Gordon’s Park earlier in the day where she met up with fellow volunteer Paul Beduhn. Mr. Beduhn, who leads “owl prowls” and night hikes at Gordon’s Park, was a perfect fit to accompany Ms. Paquette during the survey.
The primary target species for Manitoulin Island routes (there are four) were barred and Northern saw-whet owls, neither of which is at risk at this time. Surveyors also listened for long-eared owls and boreal owls. The goal of the Ontario Noctural Owl Survey is to monitor owl populations. It began in 1995 and is conducted in partnership with the Ontario Ministry of Natural Resources. Volunteers perform the actual count with a partner, using their own transportation.
According to Bird Studies Canada, owls are notoriously difficult to count. They are secretive, primarily nocturnal, and roost in concealed locations during the day. As a result, Ontario’s owl populations are not adequately monitored through existing programs.
This type of survey, called a broadcast survey, involves the playback of prerecorded owl songs and has been used to successfully census a variety of bird species. Owls are territorial and a resident owl may respond to the broadcast song in an attempt to defend its territory.
Ms. Paquette and Mr. Beduhn arrived at their starting point in Providence Bay shortly after sunset. On the way there they listened once again to the training CD that was provided to help them become familiar with the various calls. In addition to owls, surveyors are asked to record any ruffed grouse, common snipe, and American woodcock they may see or hear along their route. These birds aren’t truly nocturnal but they are most active at dusk and at dawn and are likely to be heard at the first few stops. On this route, several ruffed grouse were heard.
At the first stop, Ms. Paquette played the 12-minute MP3 through a Bluetooth speaker set on the roof of her car. It consisted of two minutes of silent listening, followed by one set of boreal owl calls and four sets of barred owl calls alternating with timed listening periods. There were no sounds to report so the team drove two kilometres down Government Road to stop number two. There were 10 stops in total.
It’s not as easy as it sounds. You have to stand relatively still on a cold April night while listening intently for specific and possibly distant sounds. Still, “it was interesting,” Ms. Paquette said when it was all over. “I think we did better than expected as far as the total number of species heard. We heard a boreal owl at stop four, a barred owl at stop six, and both a northern saw-whet owl and a long-eared owl at stop eight. We also heard ruffed grouse “drumming” at three of the 10 locations.”
There were no vehicles encountered and the noise level was “very low to moderate.” It was most noisy in areas with water such as running streams or waves breaking at Providence Bay, or in marshy areas where the spring peepers and other frogs were calling. At one stop a coyote howled nearby. Most of the owl calls were heard where there was a combination of open fields bordering on forest.
Mr. Beduhn agreed that it was “cool to learn that they (owls) are spread out around the Island so well (even though we only surveyed a small area).” He also enjoyed listening for other night sounds. For future owl prowls, he will “definitely be letting others know about the experience, and to get them to just listen to all the other sounds that are happening while we listen for the owls.”
The 2014 survey won’t be completed until the end of April. “This year may actually run late due to the lack of accessible roads in the North,” said Kathy Jones, Ontario Programs Volunteer Coordinator with Bird Studies Canada. She may be able to “ball park some information regarding the Manitoulin routes in late May or early June” but specific details won’t be available until the analysis is complete in the fall/winter.
Numbers of most owl species showed a decline in 2013 for both the central and Northern Ontario regions surveyed. The barred owl was again the most frequently detected owl while boreal owl numbers dropped dramatically in 2013. In any case, said Ms. Jones, “long-term studies do not look at single year snapshots of these species as they do not provide a good idea of populations. If you check the barred owl graph you will see the numbers go up and down each year—it is the long term trend that is important.”
by Lori Thompson
