A local conservation society is spearheading a project to learn more about the eagles that nest in the Lower Mainland by fitting them with tiny, high-tech backpacks to track their movement.

David Hancock, director of the Hancock Wildlife Foundation, is an eagle biologist involved in the Bald Eagle Tracking Alliance. So far, they've trapped five birds and released them with the lightweight devices.

"The lower Fraser Valley probably has at least 35,000 eagles passing through it every year," Hancock said. "But we don't know where they come from, or where they go."

The little backpacks are solar-powered and equipped with GPS trackers. Each one costs about $4,000. Whenever a bird flies within range of a cell tower, the device downloads data that tells researchers where the eagle has been.

So far, the birds have been covering an impressive amount of ground.

The first eagle they put the device on spent its first day hanging around the Vancouver landfill—the same place researchers found it. The next day, it flew down to White Rock. From there, it made its way to Bellingham. Then, the bird dropped off the radar.

Over a month later, its tracker checked in again. The bird had gone across the Coast Mountains and south to the edge of Washington and Oregon, hanging around a deep valley. From there, it went back up north crossing over Port Moody. The last time Hancock checked, the bird had flown past Sechelt and gone out of range again.

"We really don't know much about the travels of eagles," Hancock said. "A friend of mine trapped nine in Louisiana … by June, every one of those birds had crossed the Canadian border."

Hancock wonders if some of the thousands of birds that spend time in the Lower Mainland are "snowbirds" coming down to nest from northern Alaska. Perhaps others breed in California and then come here.

But wherever they're from, Hancock is just happy there are so many. He said he used to only be able to find three nesting pairs in the whole Lower Mainland, but now there are over 400.

"That's what's kept me going all these years," he said. "It's that I've seen at least something positive about conservation. We've changed our attitude."

Hancock's group is also testing the birds' feathers for pesticides and heavy metals. Since the birds shed their feathers so infrequently, researchers can use the GPS data to figure out where they're coming across those in their environment.

Anyone interested in where the eagles are going can watch them on the BETA website. The project is accepting donations, and some donors could have an eagle named after them.

With a report from CTV Vancouver's Michele Brunoro