Do Condors Flap Their Wings? How They Soar Without Flapping

What the 2020 condor study found

In 2020, a team of researchers led by Hannah Williams published a study of flight in the Andean condor, the heaviest soaring bird. They fitted wild condors in Argentine Patagonia with small recorders, often called “daily diaries”, that log every wingbeat, along with movement and position many times a second.

Over more than 216 hours of recorded flight, the results were striking:

• The condors spent only about 1% of their flight time flapping.
• About 75% of all flapping happened during takeoff.
• One condor flew for more than five hours and covered about 170 km (106 mi) without flapping.

The researchers also found that condors kept soaring across a wide range of wind and thermal conditions. The extra effort came at the hardest moments: getting airborne, and crossing between weak thermals early in the day, when birds flapped near the end of a glide to reach the next updraft. Even in winter, with weak thermals, condors were predicted to flap for only about 2 seconds per kilometer. The study concluded that takeoff, more than anything else, limits the flight effort of the largest soaring birds.

How condors stay up without flapping

Condors use the energy of moving air instead of their muscles. There are three main sources of lift:

• Thermals. When the sun warms the ground, columns of warm air rise. A condor circles inside a thermal to gain height, then glides off in a straight line, slowly losing height until it finds the next thermal. This is the same reason vultures circle in the sky.
• Ridge or slope lift. When wind blows against a cliff, canyon wall or mountain ridge, it is forced upward. Condors glide along these slopes, sometimes for many kilometers, riding the updraft like a surfer on a wave.
• Coastal winds. Along the Pacific coast of Peru and Chile, steady sea breezes blowing against coastal cliffs give condors reliable lift for patrolling beaches.

Charles Darwin noticed this in the 1830s. In his account of the voyage of HMS Beagle, he described watching condors for half an hour without seeing them flap their wings.

Why condors avoid flapping

Flapping flight is very expensive for a large bird. The power needed to flap rises faster than body weight, so the heaviest birds struggle the most. An Andean condor can weigh up to about 15 kg (33 lb), among the heaviest of all flying birds.

Condors are built for soaring rather than flapping. Their breastbone is relatively small, so they cannot carry the huge flight muscles of strong flappers. Instead, they have very broad wings with the largest surface area of any living bird, plus long, separated feathers at the wingtips that reduce drag at slow speeds. Read more about their dimensions in how big an Andean condor is.

The trade-off is that condors depend on the weather. On days without wind or sun, or early in the morning before the air warms, they usually stay perched on cliffs.

Takeoff: the hardest part

Takeoff is when condors work hardest. To get airborne from flat ground, a condor runs a few steps and beats its wings heavily, which is exhausting. That is why condors prefer to roost on cliffs and high ledges, where they can simply open their wings and drop into the wind.

After a big meal, the problem gets worse. A condor that has gorged on a carcass may be too heavy to take off at all until it has digested some of its food.

Do California condors fly the same way?

Yes. The California condor is slightly lighter but uses the same style of flight. It flaps mainly when taking off, then soars on thermals and ridge lift, often traveling long distances without a wingbeat. California condors can cover more than 150 km (93 mi) in a day in search of food.

Both condors share this lifestyle with other large soaring birds, such as vultures, eagles, storks and pelicans. Albatrosses also travel huge distances with little flapping, but they use a different trick called dynamic soaring, gaining energy from the difference in wind speed just above the ocean waves.

Why it matters for conservation

Knowing how condors fly helps conservationists understand where they can live and travel. Condors need places with reliable rising air, such as mountains, cliffs and coasts, as well as safe roosts for takeoff. Studies of flight can also show how changes in weather patterns and wind energy developments might affect where condors are able to forage.