Shrill beeps pulse through the seaside woods at nightfall in Metchosin. For wildlife biologist Paul Levesque, BSc ’01, it’s the same drill each weekend from mid-September until the first weekend in November. He and his dedicated group of volunteers stake-out a section of the Rocky Point Bird Observatory and with the help of their electronic lure, get a little closer to understanding the secret world of Northern Saw-whet owls.
“Most British Columbians have never seen a Northern Saw-whet owl,” says Levesque, who travels down from Black Creek and his daytime job as a forest industry consultant. “They’re one of the least-studied species.”
Loss of habitat through urban development and industrial forestry make owl populations on Vancouver Island a growing conservation concern. The Nocturnal Owl Monitoring Project started in 2002 with a small Public Conservation Assistance Fund equipment grant. The project has thrived on the efforts of “hard-working and enthusiastic” volunteers.
“We banded over 400 Saw-whet owls last year,” Levesque says. “There’s no way this area could sustain that population, which means the owls appear to be migrating. We didn’t know the owls were migrating in BC before this project. The big problem is we don’t know where they’re from and how far south they go.”
At dusk, the team sets up fine “mist nets” near the forest, then backs away to the portable lab, a roofed picnic table a hundred metres away from dense woods in one direction and a few hundred metres away from the ocean in another.
Then it’s out go the lights. Time to engage the audio-lure and enjoy the relentless male solicitation call of the Northern Saw-whet, which can be heard for a radius of 400 metres. “If there’s a male owl in the area,” says Levesque, “he’ll want to see who’s calling.”
Owls chirp, squeal then fall silent as they hit the net. After 15 minutes, there can be up to seven dangling owls to detangle, which is where volunteers are vital—more hands mean the trapped owls spend less time in the nets. “We try to reduce the amount of time handling the birds,” says Levesque. “We’ve never had an injury. I wouldn’t do this if it injured the birds in any way.”
The miniature owls measure about six inches high and weigh between 60 and 110 grams—about the same weight as a Frisbee. Each one is tagged with a tiny aluminum band with a unique nine-digit identification number. Records are filed with Canada Wildlife Service so that recovered owls can be traced and Levesque’s team notified. Although their migratory route is still undetermined, owls have been recaptured as far south as Washington State.
Wings, tails, bills are measured and age is determined by examining feathers. The bird is then placed in a Pringles potato chip can and weighed.
Examined and banded, the bird is freed on a nearby branch. “About half fly off, the other half sit and watch us work,” he says. “It’s pretty weird—there can be as many as five or six sitting around, staring at us. They’re quite curious.”
The team banded eight Barred owls in 2004, an increase from the two banded in the first year. Barred owls are a significantly larger species that Levesque says were introduced from back east about 40 years ago. They are major predators of small owls and could pose a risk to Saw-whets. For now, says Levesque, population numbers appear to be stable. He estimates three to five thousand Northern Saw-whets move through southern Vancouver Island each autumn.
“If that number represents the island population, that’s pretty good. If it’s from the Alaskan panhandle to Victoria, it’s not very many. There needs to be long-term population monitoring. Without it, by the time you detect a decline, it’s already occurring, which is not good for conservation.”
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