Why Are Bald Eagles Such Great Gliders? It’s All In The Wrist

Typography

Birds come in an astounding array of shapes and colours. But it’s their physical prowess—like a bald eagle’s incredible ability to soar—that captivates human imagination.

 

Birds come in an astounding array of shapes and colours. But it’s their physical prowess—like a bald eagle’s incredible ability to soar—that captivates human imagination.

An enduring mystery is why bird species with similar flight styles or body sizes don’t have consistent wing shapes. All hummingbirds, and some species of falcons, hawks, kingfishers and passerines can hover, but the birds have strikingly different morphologies and are only distantly related. Ravens soar like eagles while their look-alike cousins, crows, stick more closely to the ground.

New research in Science Advances helps explain why. Bird species tend to reshape the range of motion of their wings—rather than wing shape or size itself—as they evolve new ways of flying.

“Birds essentially swim through the air—they flex, extend and bend their wings in flight,” explains Vikram Baliga, a researcher at the University of British Columbia and lead author on the paper. “As a bird specializes in a flight style, nature doesn’t appear to reshape the size or shape of the wing as much as it remodels the wing’s range of motion. Much like a swimmer adjusting their stroke.”

 

Continue reading at University of British Columbia.

Image via Vikram Baliga - University of British Columbia.