Hi, Josh! I have a question about buzzards/vultures. In the afternoon I notice they fly very high up — they look like specks in the sky. Are they looking for food from up there, or can they smell food from up there, or are they just enjoying life? — Jane Spaid
It’s a great question, and one I used to wonder about all the time. I also was curious about why they so often fly around and around in circles.
But, first things first: While many people use the words interchangeably, vultures and buzzards are not the same things. Vultures are carrion specialists with generally unfeathered heads. There are species in both the New and Old Worlds. DNA studies have shown birds on different continents are not at all closely related to one another, but they are physiologically similar.
Buzzards, on the other hand, are what we call hawks — midsize broad-winged birds of prey. The only difference between a hawk and a buzzard is where it’s found. In Eurasia and Africa, they’re buzzards. In the Americas, they’re hawks.
The confusion came about because early European settlers in North America initially mistook our smaller vulture species for the buzzards they were familiar with back home. While they probably noticed the difference fairly quickly, the name had already stuck.
We have two vulture species in Florida: The black vulture and the turkey vulture. The black is more common, and noticeably more aggressive despite being about 20 percent smaller. The turkey vulture is easily recognized by its red head.
Even in high flight, you can tell them apart. Turkey vultures hold their wings in a shallow V-shape, while black vultures keep theirs straight out. When they’re well-lit, you’ll also notice that black vultures have light-colored wing tips, while turkey vultures have paler feathers across the entire trailing edge of both wings.
Both species (along with hawks and eagles) often utilize convection currents called thermals to achieve significant heights while using very little energy. How thermals form is fascinating, but for our purposes it’s enough to say that as the ground heats up during the day, it warms the air above it. We learned in grade school that hot air rises. The birds learned it too, and their broad wings are well-adapted to catch those currents — and up they go.
So, what are those vultures doing up there? Depends on the species.
Turkey vultures are true scavengers. They aren’t good at killing prey, or even at carving their way into something that’s already dead. Instead, they rely on putrefaction to get them in. Dead animals bloat and eventually rupture, exposing the well-aged and tenderized innards.
Rotting meat is known to be aromatic, and a turkey vulture has an excellent sense of smell. The same thermals that allow them to soar aloft also bring the scent of rancid flesh high into the sky, where it can be detected from a great distance. Then the bird can just follow the stink to its source. While actively scavenging, these birds fly up to a couple thousand feet high, though generally they stay below 500 feet.
Now, the black vulture is a little different. These birds are more predatory and are known to attack animals in distress. Cattle ranchers despise black vultures because they will sometimes go after newborn calves, and even the mothers if they’ve had a rough birth. They don’t have the ripping beaks of true birds of prey, but they can pluck eyeballs and tear at the orifices. It ain’t pretty.
Black vultures have a very limited sense of smell. Most of their scavenging is done visually — either by spotting something directly, or by watching turkey vultures as they home in on a carcass. It was once believed that their vision was much better than the turkey vulture’s, but recent studies have shown that both birds have high visual acuity like other raptors. However, since the black vultures can’t smell as well, they are more reliant on their eyes to find supper. With such great sight, they can scavenge effectively from up to a mile high.
Both species occasionally travel long distances. Our local Florida populations are resident, but birds living in the northern U.S. migrate south to avoid the coldest parts of winter. Black vultures tend to mix in, but turkey vultures fly farther south to areas outside the year-round range of their kind, and thus compete with each other less.
When migrating, vultures use thermals to climb far above their hunting altitude — 15,000 to 20,000 feet. Once they reach such heights, they can then glide for miles in the direction they really want to go, find another thermal, rise and glide again. Lather, rinse, repeat. This method of long-distance flight is why vultures migrate over land, even if the routes are longer. Thermals don’t form as reliably over water, and a vulture that has to flap a long distance is likely to tire itself to death.
Capt. Josh Olive is a fifth-generation native Florida Cracker and a Florida Master Naturalist, and has been fascinated by all sorts of wild things and places since he was able to walk. If you have questions about living with wildlife, contact him at Publisher@WaterLineWeekly.com or 941-276-9657. You can also follow him on Instagram @florida_is_wild.