Owl survey looks for volunteers to record these secretive birds

While the call of the robin is one of the first feathery signs of spring for most people, for Amy Kouwenberg spring means it's time for the annual owl survey.

Kouwenberg is the owl survey co-ordinator with Bird Studies Canada, a national bird conservation organization.

It puts on the Atlantic Nocturnal Owl Survey every spring between April 1 and May 15, when volunteers go out at dusk to record owl calls.

There are more than 100 volunteers covering 95 routes in Atlantic Canada.

This is the survey's 19th year, and Kouwenberg said some of the volunteers have been doing it since the beginning.

Volunteers play owl sounds

"It's one of the early examples of a citizen science project, where we're getting lots of volunteers to do work that would be very difficult to do with paid technicians," she said.

Volunteer surveyors go out with CD players and a 13-minute recording of owl sounds to play at specific stops two kilometres apart along a route. Stops have to be far enough apart to avoid double counting of owls.

Volunteers record the responses they get, and sometimes, a particularly curious or territorial bird will make an appearance. The whole outing takes two to three hours.

Kouwenberg said owls are a great indicator species of the health of forests and surrounding ecosystems. Tracking the birds over periods of time allows scientists to see how changes in the forest landscape, such as clear cutting and development, affect them.

Still, owls are a challenging bird to survey because of their nocturnal and secretive natures.

There are 41 routes in New Brunswick already assigned to volunteers, but Kouwenberg said there are several vacant routes in northern parts of the province.

That's why she'll give a presentation at the Plaster Rock Public School Library on Friday at 3:30 p.m. to try to spread awareness about owls and attract more volunteers for the survey.

Kouwenberg said the Bird Studies Canada tries to get volunteers out as early in the season as possible, since once the spring peepers start their nighttime concerts it can be hard to hear the owls over the frogs.

As the 20th year of the survey comes up, the organization is planning an extensive analysis of the data collected, she said.

So far, she said, results indicate the barred and northern saw-whet owls seem relatively stable, but great horned owls, which need large tracts of forest, are facing a decline. 

Most longtime volunteers do the same route every year, so they become quite familiar with the owls in their areas, leading to more consistent data.

Kouwenberg said the data volunteers collect will provide the science behind the advocacy Bird Studies Canada does.

"It helps us to be able to say, 'Look, we are seeing these declines here' and then being able to look at what might be causing those."