Leisha The dogs knew first. Something shifted in the air behind our property, and they stood at the fence with their noses working like they were reading a newspaper. The cats, who usually act as though nothing outside their own interests deserves attention, came and sat nearby and watched. We didn’t have to wonder long. A cow had died on our neighbor’s land, and nature, who has never needed a committee meeting to get things done, was already putting her crew to work.
Yesterday morning, the smell started with a force. And, I am pleased to share, by afternoon the sky had company. The Vultures started arriving…first circling in the sky and them zooming down to the dead cow.
I have always been fascinated by vultures. I know some people see a vulture and their stomach turns, but I see one of the most elegant systems on the planet at work. A vulture takes death, which most of us would rather not look at, and transforms it. It takes what could become a pool of disease and sends it back into the world as soil as alchemy.
That is the kind of transformation I think about constantly in my work with soil and microbes. Nothing is truly wasted in a living system. A body goes down, and something else rises.
Do Vultures Smell?
First, let’s answer can vultures smell? Yes, and some are remarkable at it.
Do vultures smell? Also yes! A roost of vultures has a bouquet all its own, a mix of ammonia, old meat, and the leftovers of a bad day. Anyone who has stood under a roosting tree knows it. But the smell has a purpose, and the vulture has worked out how to turn even its own hygiene into a tool. They have a habit called urohydrosis, which is a polite scientific word for defecating on their own legs. In hot weather, the evaporating moisture cools them down. The uric acid in the droppings also kills bacteria they pick up while walking through carcasses. It isn’t pretty, but it works, and they carry their own disinfectant with them wherever they go.
When threatened, vultures can also vomit on purpose, sometimes with surprising range. I don’t think I have ever heard of a person being hit with Vulture vomit but I suppose this is a good protection device for them. A predator that gets hit with half-digested carrion would surely lose interest. Apparently, the puking also lightens the bird so it can take off quickly. If you ever get close to a young vulture in a nest, expect to be introduced to this defense. Again, I know of no person this has happened too.
How Do Vultures Find Food?
For a long time, people assumed birds had no real sense of smell. The thinking was that birds are visual animals, with eyes for the sky and not much going on in the nose. Then in the 1960s a researcher named Kenneth Stager started testing turkey vultures and found they could locate hidden carcasses, even ones covered up so that nothing was visible from above. Their olfactory bulbs, the part of the brain that processes scent, turned out to be unusually large.
One of the best stories in vulture science comes from the gas industry. Natural gas has no smell of its own, so companies add a chemical called ethyl mercaptan so that leaks can be detected. Engineers reportedly noticed that vultures gathered over leaking pipelines. Ethyl mercaptan is also one of the first gases released when an animal begins to decompose. The vultures were following the same signal that told them dinner was ready, and it turned out to be a very practical way to find a leak in a pipe. Some utilities have used vulture behavior as a clue to where to dig.
Turkey vultures are the sniffers of the family, and this matters because not all vultures are equal here. In places with dense forest canopy, a carcass can lie completely hidden from the sky. Researchers working in Panama found that turkey vultures could locate dead animals under thick cover, while black vultures, which have a much weaker sense of smell, generally could not. The black vultures have worked out a clever workaround. They watch the turkey vultures and follow them in. Then, because they are bolder and more aggressive and tend to show up in larger groups, they muscle in on the meal. One species finds the food and the other takes over the table. It’s the kind of arrangement you would expect to see in a human neighborhood.
Smell is only part of the toolkit. Vultures also watch each other with great attention. A bird sees another bird dropping toward the ground and follows. Then another sees that one, and then another. Within a short time a whole chain of birds stretching across miles of sky is converging on one spot. Scientists describe it as a kind of information network, with each bird serving as a relay. A vulture who has no idea there is a carcass can become part of the discovery without ever smelling a thing.
Their eyesight is excellent too, and they read the land from above the way a farmer reads weather. They notice a motionless animal in a field, the behavior of other scavengers, or the telltale sign of a larger predator at a kill. Put all of this together and you have a bird that uses scent, sight, and the behavior of its neighbors to find a meal. And they do it while burning almost no energy, which brings me to the next surprise.
Built for the Job
If you were designing an animal to eat rotting meat, you would end up with something very close to a vulture.
Start with the head. Vultures are bald, which makes them look a bit like someone who lost a bet. But feathers around a carcass would be a disaster. They would soak up blood and fluid and become a permanent home for bacteria. A bare head and neck can be cleaned easily, and the sun does the rest. Bare skin also helps them shed heat in hot weather.
Then there is the stomach. Vultures have an extremely acidic digestive system, with a pH near the very bottom of the scale. This is strong enough to dissolve bone and to destroy most of the things that would kill another animal. Anthrax, botulism, cholera, and rabies are all hazards of a diet made of carcasses, and vultures can eat them and carry on with their day.
What fascinates me most is the microbiome. A research team studied the gut bacteria of vultures and found something striking. The community was remarkably narrow, with much less diversity than you would see in most animals, and it was dominated by a few specialized groups of bacteria. Some of those groups include species that cause serious illness in other creatures. The researchers suspect the vulture’s gut works as a kind of filter, with a handful of tough, well-adapted microbes standing guard and the acidity doing the rest. Facial skin carried a similar set of bacteria. If you have ever read my writing on terrain theory, you can guess what I think of this. The vulture doesn’t succeed because it avoids microbes. It succeeds because its internal terrain is so well managed that the dangerous ones can’t take hold.
Their feet are another surprise. For a bird that looks like a raptor, a vulture has weak, flat feet, more like a chicken’s than an eagle’s. They are built for walking and standing and for holding a carcass in place, not for grabbing and killing. This is a clue about their history and their way of life. They are not hunters. They arrive after the work is done.
Vultures also have no voice box, at least not in the way songbirds do. The New World vultures lack a syrinx, so they can only hiss, grunt, and wheeze. If you hear one making noise, it sounds like a very annoyed old man clearing his throat. Because they cannot call to each other across a distance, they rely on body language and on watching each other, which fits perfectly with the way they find food.
Masters of the Air
If vultures have an image problem on the ground, the sky is where they redeem themselves. A turkey vulture spreads its wings in a shallow V and rocks gently from side to side, as if testing the air. They are hunting for thermals, the rising columns of warm air that form when the sun heats the ground. Once a vulture finds one, it climbs in lazy circles with barely a wingbeat, then glides out to the next. A group of vultures circling in a thermal is called a kettle, and when you see one, you are watching a flock use the sun itself as an engine.
The Andean condor, which is also a New World vulture and which appears on Ecuador’s coat of arms, takes this to an extreme. With a wingspan of around ten feet, it is one of the largest flying birds in the world. Researchers fitted wild condors with sensors and found that the birds flapped for only about one percent of the time they were in the air. One condor flew for five hours without a single wingbeat. It makes you wonder how much of our own effort is wasted by pushing when we could be waiting for the lift.
A Surprisingly Social Life
Vultures are not loners. They roost together in large groups, and the vocabulary for these gatherings is wonderful. A group in flight is a kettle. A group resting in trees is a committee. A group feeding on a carcass is a wake. I can’t think of a more perfect word for a gathering around the dead.
Many species form lasting pairs, and black vultures in particular have strong family bonds. They build no real nest, laying eggs on bare ground in a cave, a hollow log, or a quiet thicket. Both parents help raise the chicks, feeding them by regurgitating food. A young vulture may stay with its parents for a long time and learn the whole system by watching them.
What Vultures Mean
Symbolism is where the story gets rich, because every culture that has lived under vultures has had something to say about them.
In ancient Egypt, the vulture goddess Nekhbet protected the pharaohs and watched over Upper Egypt, and the royal crown included a vulture head. The hieroglyph for the word “mother” was a vulture. Ancient writers even believed that all vultures were female and were fertilized by the wind. The bird associated with death was also the bird that stood for motherhood and protection, which tells you how the Egyptians understood the relationship between the two.
According to the Rome legend, the twin brothers Romulus and Remus each looked to the sky for a sign of who should rule. Remus saw six vultures. Romulus saw twelve. Romulus got the city and the name. Roman priests called augurs read the flight of birds as messages from the gods, and vultures were among the most respected signs.
In Tibetan Buddhism, a practice known as sky burial offers the body to the vultures as a final act of generosity. It reflects the teaching that the body is an empty vessel and that the greatest gift is to feed other living beings. I find it hard to think of a more honest way to meet the end of a life.
Many Indigenous traditions in the Americas see the vulture as a purifier and a symbol of renewal. The bird that cleans the land and takes in what has died is understood as a healer. In the Andes, the condor is a bridge between the earth and the upper world, a messenger that carries prayers to the sky.
Then there is the Western imagination, which has not been kind. In old movies, a vulture circling overhead means someone in the desert is about to die. We use the word “vulture” as an insult for anyone who preys on the misfortune of others. This is unfair to the bird in a way that is almost funny. A vulture doesn’t create misfortune. It arrives afterward and does the work no one else wants to do. If anything, we are the ones who should be called vultures for the way we profit from each other’s troubles, because the birds never do.
What Happens When They Disappear
If you doubt that vultures matter, look at what happened in India. In the 1990s, populations of several vulture species began to collapse. Within a few years, some had declined by more than ninety-five percent, and a couple of species were nearly gone. The cause turned out to be a veterinary drug called diclofenac, an anti-inflammatory given to cattle. When the cattle died and the vultures ate the carcasses, the drug destroyed their kidneys.
The consequences spread outward. Carcasses that vultures would have cleaned up in hours now sat rotting in the open. Feral dog populations rose, and with them came more rabies. One economic analysis estimated that the loss of vultures may have contributed to hundreds of thousands of additional human deaths over a period of just a few years. Think about that for a moment. A bird we consider repulsive was quietly standing between a whole region and an epidemic.
Africa has seen similar losses from poisoning, often as a side effect of poachers who lace carcasses to hide their crimes. Vultures are now among the most threatened groups of birds in the world. The cleanup crew is disappearing, and the cost is high.
Back at the Fence
I think about all of this at this moment knowing the neighbor’s field is smelly feast. My dogs have settled down, and the cats have gone back to their usual indifference. In the sky, dark shapes tilt and turn and drop one by one toward the ground. I am sure within a few days there will be very little left. The bones will go back to the soil. The nutrients will feed the grass, the grass will feed the next animal, and the vultures will roost in the trees, wherever they roost, and digest the evidence of a life that has been returned to the cycle.
Everything I teach about soil and microbes comes back to this. Death isn’t an ending in a living system. It’s a hand-off, and the vulture is one of the hands. We spend a great deal of energy in our culture trying to avoid, hide, and sanitize the end of life. The vulture does the opposite. It shows up, does the work, and leaves the world a little cleaner than it found it.
Here is a video I captured of the vultures coming to my pond to have a drink. So the next time you see a kettle of vultures turning in the sky, try not to flinch. Look up and say thank you. Somewhere below them, something has finished its time, and the work of turning it back into life is already underway.
