By Chrissy Sexton Earth.com staff writer
New research from Ghent University in Belgium has revealed that the color of a bird’s wings plays an important role in flight efficiency. The study suggests that darker wing feathers give birds an aerodynamic advantage.
The experts set out to analyze how the color of bird feathers may affect wing temperature, and whether darker wings may heat up faster than lighter wings under solar radiation.
Using thermal imaging, the researchers examined the surface temperature changes in the feathers of two live osprey with increased solar radiation.
In addition, the team experimentally heated different colored wings in a wind tunnel and measured wing temperatures during flight. Osprey, gannet, and back-blacked gull wings were exposed to various realistic wind speeds.
The team discovered that dark feathers not only warm up the wings but also the surrounding air, which increases air flow. According to the study, a common wing pattern consisting of white feathers at the body and black feathers at the wing tips seems to help lift the wings.
“Even under simulated flight conditions, darker wings consistently became hotter than pale wings. In white wings with black tips, the temperature differential produced convective currents towards the darker wing tips that could lead to an increase in lift,” wrote the study authors.
The darker feathers were found to heat up much more than light feathers. “We found temperature differences of about 9 degrees between black and white,” study lead author Svana Rogalla told New Scientist. “We would even find these temperature differences in the same wing.”
The study is published in the Journal of the Royal Society Interface.