blackpoll

Norris said scientists had long believed that blackpolls followed the great circle route.

For the first time, University of Guelph biologists have tracked an annual migration of up to 20,000 kilometres made by the 12-gram blackpoll warbler, one of the fastest declining songbirds in North America.

"As a conservation scientist, what strikes me most is that in a single year a blackpoll warbler has to navigate 20,000 kilometres across land and ocean, facing risks of cat predation, storms and collisions with buildings and vehicles, all while trying to find islands of habitat to rest and refuel in our human-dominated landscapes,"said Cooke.