Bird flight without flapping? Yep, it’s possible. A new study shows Andean condors surf air 99% of the time.

God made the world’s largest soaring bird surprisingly efficient. “Condors are expert pilots—but we just hadn’t expected they would be quite so expert,” says Emily Shepard, study co-author and biologist at Swansea University in Wales. Condors clean up carrion from the Patagonia plateau in South America. But these effective waste disposers are also proficient fliers. They use air currents to stay aloft for hours without flapping their wings.

The Andean condor has a wingspan stretching to 10 feet and weighs up to 33 pounds, making it the heaviest soaring bird alive today.

For the first time, a team of scientists strapped recording equipment they called “daily diaries” to eight condors in Patagonia. The devices recorded each wingbeat over more than 250 hours of flight time.

Incredibly, the birds spent just 1% of their time aloft flapping their wings. What little flapping they did occurred mostly during takeoff. One bird flew more than five hours, covering over 100 miles, without flapping its wings even once.

“The finding that they basically almost never beat their wings and just soar is mind-blowing,” says David Lentink, an expert in bird flight at Stanford University.

To birds, the sky is not empty. It’s a landscape of invisible features—wind gusts, currents of warm rising air, and streams of air pushed upward by ground features such as mountains.

Riding air currents allows some birds to travel long distances while minimizing the exertion of beating their wings.

Scientists who study flying animals generally consider two types of flight: flapping flight and soaring flight. The difference? Flapping can be compared to peddling a bicycle uphill. Soaring is like coasting downhill.

Past studies have shown that white storks and osprey flap for 17% and 25% of their overland migratory flights, respectively.

The Andean condor’s extreme skill at soaring is essential for its scavenger lifestyle. Condors must spend hours each day circling high mountains looking for a meal of dead animal. A circling condor is using rising warm air gusts to move.

The recording devices were programmed to fall off the birds after about a week. Retrieving them wasn’t so easy. “Sometimes the devices dropped off into nests on huge cliffs in the middle of the Andes Mountains, and we needed three days just to get there,” says biologist and study co-author Sergio Lambertucci.

They who wait for the Lord shall renew their strength; they shall mount up with wings like eagles; they shall run and not be weary; they shall walk and not faint. — Isaiah 40:31