New research has revealed when it comes to flying, the largest of birds don’t rely on flapping to move around. Instead they make use of air currents to keep them airborne for hours at a time.
The Andean Condor — the world’s heaviest soaring bird which can weigh in at up to 33 pounds (15kg) — flaps its wings for one percent of its flight time.
The study is part of a collaboration between Emily Shepard of Swansea University and Sergio Lambertucci in Argentina. They use high-tech flight recorders on the condors. The devices log every wingbeat and twist and turn in flight as condors search for food.
The team wanted to find out more about how birds’ flight efforts vary depending on environmental conditions. Their findings will help to improve understanding about large birds’ capacity for soaring and the specific circumstances that make flight costly.
During the study, the researchers discovered that more than 75 percent of the condors’ flapping was associated with take-off.
However, once in the sky condors can sustain soaring for long periods in a wide range of wind and thermal conditions. One bird managed to clock up five hours without flapping, covering around 172 km or more than 100 miles.
The findings are revealed in a new paper published by Proceedings of the National Academy of Sciences.
“Watching birds from kites to eagles fly, you might wonder if they ever flap,” says coauthor Hannah Williams, now at the Max Planck Institute for Animal Behavior. “This question is important, because by the time birds are as big as condors, theory tells us they are dependent on soaring to get around.
“Our results revealed the amount the birds flapped didn’t change substantially with the weather. This suggests that decisions about when and where to land are crucial, as not only do condors need to be able to take off again, but unnecessary landings will add significantly to their overall flight costs.”
Thanks to Swansea University for providing this news.