A Boeing 737 requires a lot of jet fuel to stay up in the air: at least 750 gallons every hour. Flying, as humans have learned, takes a lot of free energy. For birds, maintaining their own bodies up in the sky for hours, days, and even months can also be incredibly costly, but they've at to the lowest degree evolved for the job. Small birds like warblers are lightweight enough that they can remain airborne by rapidly flapping their wings. For heavier birds, though, flapping takes too much energy. When bird species attain the size of a pocket-size raptor, they start to rely on other types of flight: soaring and gliding.

Through soaring, birds gain altitude and travel quickly past taking energy from current of air currents in the atmosphere. When they glide, they use the position of their wings to deflect air down, which creates a forcefulness chosen "updraft" that keeps them upwardly in the air. There are different kinds of soaring and gliding, and birds use them in a variety of ways.

"The air is this astonishing environment that'southward on the move all the time," says Emily Shepard, a researcher who studies creature movement at Swansea Academy in Wales. "It's merely fascinating to encounter how it tin can create both opportunities and risks for different species." Run across some of the masters of these flying techniques.

Wandering Albatrosses

"Wandering Albatrosses are the ultimate soaring birds," says Anders Hedenström, an animal flight expert at Sweden'south Lund University. When you lot take a look at their bodies, yous understand why: With wings reaching xi to 12 anxiety long from tip to tip, they have the largest wingspan of whatever living bird. Those wings tin can keep their sparse, cigarette-like bodies aloft for days at a time.

Wandering Albatrosses spend between 1.2 to 14.5 percent of their flight time slowly flapping to stay in the air, researchers have establish. The rest of the time their wings are splayed wide. Like many other birds, Wandering Albatrosses soar past catching a ride on thermals—hot air rising from the ground—to gain distance. Simply what makes them unique is their impressive power to engage in a type of flight called "dynamic soaring," which tin can only happen while flying over the sea, says Todd Katzner, a wild animals biologist at the U.S. Geological Survey.

In dynamic soaring, albatrosses take advantage of the dissimilar speeds and directions air current flows depending on how shut it is to the Earth's surface. The birds start close to the ocean, where they grab a ride upward on a thermal. They slowly climb, and when they achieve high altitudes, where wind moves faster, they shift to fly in the same direction of the wind. That way, they can glide at a relatively fast speed while descending. By the time they are at lower altitudes, where wind is moving slowly, they have picked upward a lot of momentum and are moving fast. That lets them turn their bodies diagonally in the direction they want to travel, even if information technology'south confronting the current of air. Finally, when they are running out of energy and slowing downwardly, they restart the cycle past catching another thermal.

Accompanied past maneuvers that utilize the motility of the wind rising over waves, dynamic soaring is how Wandering Albatrosses manage to travel up to 3,000 miles a week using barely whatever free energy.

Andean Condors

If Wandering Albatrosses are the soaring masters of the sea, at that place is no doubt Andean Condors take the crown for inland birds. Research published recently showed that the Andean Condor—the heaviest soaring bird, at 35 pounds—flaps less during flying than any other costless-ranging bird. After following eight Andean Condors for 5 years, a squad of European and Latin American scientists institute that even young birds soar about 99 percent of their flight time. "They are the extreme version of a soaring bird. It was fascinating to us," says Emily Shepard, the lead author of the written report.

The researchers found that these giant birds flap merely during take-off and landing. They are so massive that they lose altitude fifty-fifty when flapping as fast as they tin can. This means that their reliance on wind currents is nearly accented, says Shepard. So, to stay in the air, Andean Condors mostly utilize thermals to elevate. Once they're high plenty, they tin glide betwixt thermals looking for food. Less often they utilize some other blazon of air electric current called "orographic updraft" that forms when the wind collides with an object—similar a mountain or a building—and changes its direction to go upwards.

The researchers are now focusing on agreement the social aspects of soaring, or how a group of birds using the same air resources influence each other's decisions—such equally when to spring from one thermal to another, or picking the best spot to country or have off, says co-author Hannah Williams.

Great Frigatebirds

Nifty Frigatebirds make the "heaven masters" podium because they can successfully soar through doldrums—areas in the open ocean where the current of air doesn't blow. How exercise they do it? In 2016, a team of researchers uncovered the mystery.

Similar many other soaring birds, Great Frigatebirds use thermals to gain distance. But unlike the others, they ride powerful thermals within white and puffy cumulus clouds, which can elevate them 13 feet per second. "It'southward the only bird that is known to enter into a deject intentionally," Henri Weimerskirch, lead writer of the newspaper describing this beliefs, told NPR in 2016. By doing so the birds can reach altitudes as high as 13,000 feet.

The amount of fourth dimension they tin soar without stopping is also impressive. While migrating through the Indian Bounding main, the birds tin stay in the air for up to two months, gliding between thermals while scanning for food on the surface of the sea. I tagged frigatebird traveled 34,000 miles in 185 days, stopping briefly on small islands for just 4 days! Such an accomplishment could merely be accomplished by the bird with the greatest wing-area-to-body-mass ratio in the world. It too helps that they can sleep on the wing.

American White Pelicans

American White Pelicans have a trick under their wing that sets them apart from other birds on this list: miniature tornados. White Pelicans migrate in flocks, arranging themselves in a feature V germination to salve free energy together. The separated feathers at the tip of each bird's wing creates a force called a "wingtip vortex," Hedenström says. By flying in a V formation, each bird (except for the leader) can get lift from the wingtip vortex created by the bird alee of it in line. A study on their shut relative, the Great White Pelican on the other side of the Atlantic, showed birds could reduce their energy expenditure by xiv percent flying in this formation.

But that's non the simply way American White Pelicans save free energy while migrating. They  also alter their flight blueprint depending on the season, a 2017 study revealed. While they rely on updrafts and thermalsduring their spring migration from their wintering sites in Alabama, Louisiana, and Mississippi to their breeding sites in the Northern Great Plains, they tend to be carried by a tailwind during the fall, when air currents are weaker. The different strategies made their migration speed significantly unlike: nigh 24 miles per hour during the spring, and 20 miles per hour in the fall.

Golden Eagles

For many birds on this list, soaring is a largely passive action. They travel in a general direction, guided largely by wind currents, and proceed their eyes open for food to scavenge or prey that's relatively easy to catch. Gold Eagles, though, engage in more circuitous activities while soaring. They hunt small and medium-size mammals. They stake out and defend territories of around 6,000 acres. They fifty-fifty play fetch with themselves. That complexity in behavior sets them apart from other big soaring species like vultures and condors, says Todd Katzner. "Golden Eagles, and other big eagles, are kind of unique because not just do they soar, but they soar to do all this crazy stuff," he says. They don't do very much flapping at all: It only takes up between 3 and xv percent of their flight time.

Katzner studies a small Golden Eagle population that migrates and winters along the Appalachian Mountains. These birds don't accept access to strong thermals similar their European peers residing about the Mediterranean, Katzner says. These birds accept had to diversify the types of air currents they utilize to stay in the air. When migrating, they soar in thermals for near 41 pct of their flight fourth dimension, glide between thermals about 45 percent of the time, and soar using orographic updraft, just like Andean Condors, about 13 pct of the time.

Turkey Vultures

Turkey Vultures are unlike from other vultures throughout the world. Most vulture species rely heavily on soaring and gliding through the air at very high altitudes (up to 37,000 feet), says Katzner, and they rely heavily on sharp vision to see the carcasses of dead animals from such a height. But Turkey Vultures have adapted to fly at lower altitudes to sniff the all-time pieces of carrion. In fact, they have ane of the best smelling systems of all birds. In 2017, afterward comparison them with other 32 species, a team of researchers proved that Turkey Vultures has more mitral cells, which transmit information about odors to the brain, than any of the other measured species.

These birds fly using a type of soaring called "contorted soaring." Through this technique, Turkey Vultures ride the upwards wind generated when air currents collide with treetops. This allows them to stay closer to the footing compared to other carrion eaters, like Black Vultures in Northward America, giving them an reward. They tin also rock side-to-side while flying to annul the wind forces in turbulent scenarios, which allows them to have a lot of control and stability in their flight. "They can fly with nearly no wind and in very turbulent settings," Katzner says. "They are merely i of the coolest species in Due north American to me."

White Storks

White Storks spend more time flapping than the other birds on this list: It takes upward about 17 pct of their flight fourth dimension, which is still significantly less than most bird species. What makes them fascinating, says Hannah Williams, is how their social interactions shape the amount of soaring, gliding, and flapping of each bird.

Afterwards following a grouping of 27 White Storks for four years, researchers institute that, when migrating, the lead bird has a more irregular flight blueprint than the rest of the flock following backside. It didn't necessarily fly in a straight line, and spent most of its time exploring thermals. The researchers recall that'southward because the birdin front is in accuse of finding new thermals that the other birds use to gain altitude. Meanwhile, the followers in the flock flapped more often to avert falling behind the grouping.

In the end, these differences influenced where follower and leader storks spent the winter.  Frequent-flapping follower birds spent more energy and were able to fly only 621 miles (1,000 kilometers) from Lake Constance—where Germany, Switzerland, and Republic of austria meet—to Spain. The leaders, on the other hand, were able to fly more than 2,485 miles (4,000 kilometers), wintering in northern Africa instead.