Vultures fly in circles to ride columns of rising warm air called thermals, which let them gain altitude without flapping their wings. This saves an enormous amount of energy. Once airborne in a thermal, a vulture’s heart rate drops to near-resting levels, meaning soaring costs roughly the same energy as sitting on a perch. Circling also helps vultures scan for food, pick up scent trails, and watch what other vultures are doing.
Thermals Require Circular Flight
A thermal is a column of warm air rising from sun-heated ground. These columns are relatively narrow, so a vulture can’t simply fly in a straight line through one and gain much altitude. Instead, it banks into a turn and spirals upward inside the column, riding the rising air like an elevator. The physics of this maneuver create a balancing act: the bird’s banked wings must simultaneously counteract gravity pulling it down and the centripetal force pushing it outward through the turn. Flying in a tight circle keeps the vulture centered in the strongest part of the updraft.
At low altitudes, vultures typically circle with a radius of about 28 meters (roughly 90 feet). As they climb higher where the air is thinner and provides less lift, they widen their circles by as much as 56%, expanding to a radius of about 44 meters. This adjustment keeps them from losing altitude as atmospheric conditions change beneath their wings. The result is that distinctive, lazy spiral that’s visible from the ground.
Soaring Costs Almost Nothing
Flapping flight is expensive. When a vulture takes off or lands, its heart rate spikes above 300 beats per minute, more than triple its resting rate. But within about 10 minutes of catching a thermal and switching to soaring, its heart rate drops back to 80 to 100 beats per minute, essentially the same as when the bird is perched and doing nothing. Soaring uses two to three times less energy than flapping or even walking on the ground.
This efficiency is staggering. Vultures flap for less than 5% of their total flight time. The rest is pure gliding and soaring, powered entirely by the atmosphere. A turkey vulture sinks at a minimum rate of about 2 feet per second while gliding, but as long as the thermal beneath it rises faster than that, the bird climbs. It’s gaining altitude while barely burning calories.
Wings Built for the Job
Vulture wings are specifically shaped for this style of flight. They’re broad and relatively short compared to, say, an albatross, giving vultures a low wing loading (the ratio of body weight to wing area). This lets them stay airborne at slow speeds and maneuver tightly inside thermals. The tradeoff is that short, broad wings create a lot of drag, which would normally slow the bird down. Vultures solve this by spreading their primary feathers at the wingtips like fingers, creating slots between them. Each separated feather acts as its own small, efficient wing, reducing turbulence and lowering the speed at which the bird would stall. That’s why you can often see vultures soaring with their wingtip feathers visibly splayed apart.
Searching for Food From Above
Circling at altitude is also a hunting strategy, though “hunting” is generous since vultures eat animals that are already dead. How they find those carcasses depends on the species.
Turkey vultures rely heavily on smell. They have the largest olfactory bulbs of any bird, both in absolute size and relative to brain size. Those bulbs contain twice as many of the specialized nerve cells responsible for processing scent information as the closely related black vulture, despite the turkey vulture having a 20% smaller brain overall. Combined with large, complexly folded nasal passages that increase the surface area for detecting odors, this gives turkey vultures an exceptionally sensitive nose. They pick up a chemical released by decaying flesh and can track it to a carcass hidden under a forest canopy without ever seeing it. To do this effectively, they fly relatively low, where scent concentrations are strongest.
Black vultures take a different approach. They search visually and benefit from soaring at higher altitudes where they can scan larger areas of ground. They also watch other vultures closely. When a turkey vulture drops toward a carcass it has sniffed out, nearby black vultures notice the descent and follow. This piggyback strategy means black vultures often arrive at a meal they never would have found on their own.
Vultures Watch Each Other Constantly
Social information drives much of what vultures do in the air. In a study tracking the flight decisions of free-flying vultures, researchers found that 63% of their thermal soaring took place in thermals that another vulture had discovered first. When given a choice between two available thermals, a vulture was roughly 28 times more likely to join the one with the most birds already in it. This isn’t random flocking. Vultures actively choose crowded thermals because more birds means more eyes scanning for food and more reliable information about where the best lift is.
This reliance on social cues intensifies in poor weather, when thermals are weaker and harder to predict. Under those conditions, following other vultures to a proven thermal reduces the risk of getting stranded on the ground. The tradeoff is competition: more vultures at a carcass means less food per bird. But the benefit of finding thermals and food sources reliably outweighs the cost of sharing.
Assessing a Meal Before Landing
When vultures spot a potential carcass, they don’t dive straight down. They circle above it first, sometimes for several minutes. This serves a practical purpose. The birds are checking whether the animal is truly dead, whether larger predators are still nearby, and whether something has already torn open the carcass, which makes it easier for vultures to feed since their beaks aren’t well suited to breaking through tough hide. Only once the coast looks clear do they spiral down to land.
This cautious circling over a food source is probably what gave rise to the popular image of vultures ominously wheeling over a dying creature. In reality, vultures rarely circle a living animal. They’re scavengers, not predators, and they’re waiting for confirmation that a meal is safe to approach.
Why You See It More at Certain Times
Thermals depend on the sun heating the ground, so they’re weakest in the early morning and strongest from mid-morning through the afternoon. Vultures typically can’t get airborne until thermals develop enough to support their weight, which is why you’ll often see them perched with wings spread in the morning sun, warming up and waiting. Once conditions are right, they launch and begin circling, and they stay aloft until thermals weaken in the late afternoon. This is why large groups of circling vultures, sometimes called kettles, are most visible during the warmest hours of the day.
Younger vultures struggle more with weak thermals. Adult vultures outperform juveniles in challenging soaring conditions, likely because reading thermals and choosing the right moment to transition between them takes experience. A skilled adult can stay airborne in marginal conditions that would ground a younger bird.