Weather Features

Migrating Birds Offer Clues To Climate Change

BOSTON (WBZ) ― There is plenty of music in the air these days, thanks to hundreds of thousands of migrating birds heading north to breed during the warmer months of the year.
 
Researchers at the Manomet Center for Conservation Sciences are closely studying our feathered friends to see what impact climate change is having on their journey.
 
Birds like the Magnolia Warbler, flying thousands of miles from Central America to breed in New England. Along the way, there's a pit stop for science. They're part of a massive study on bird migration.
 
Many birds opt for migration routes along the coast because of coastal storms. The storms produce wind, the wind knocks down trees and limbs, allowing enough sunlight through so that bushes can flourish.

The bushes are filled with insects in the spring and berries in the fall - both key food sources for birds on the move.

The researchers capture birds on nets, then it's back to the lab for tagging and measurement.

"Each of these bands is like a social security number," said Trevor Lloyd-Evans, a senior biologist at the Manomet Center.

That number is linked to all the bird's vital stats - including wing length, weight and age.

Once all measurements have been made, the bird is released. 

For more than three decades, some 350,000 birds have been recorded, enough to tease out the impact of our changing climate.

"We are finding that the average bird in many cases is indeed coming back a little earlier," said Lloyd-Evans.

The birds returning earlier are adapting well. They're acting on weather cues in the southern U.S. where they spend the winter.

"They are realizing its warmer and they are able to come back at little earlier because their cue is temperature," said Lloyd-Evans.

But long distance migrants like the magnolia warbler are not, because their travels are based on an internal clock

"That tells you nothing about the weather and so you can get out of sync."

And out of sync means missing the peak of the food supply which can result in less fuel for flight and for feeding the young.

The populations of many migratory birds are declining, so Lloyd-Evans plans to expand the study to determine if their food sources are being impacted by climate change.

For more information, visit www.manomet.org

(© MMVIII, CBS Broadcasting Inc. All Rights Reserved.)