Friday, July 25, 2014

Vultures Are Vomiters, Not Raptors

For years, it was believed that all vultures were raptors, members of the order Falconiformes.

In 1994, however, it was discovered that vultures on this side of the Atlantic actually share a common ancestor with storks and ibises. Now, New World vultures are recognized as Ciconiiformes, in the family Cathartidae, while European, African, and Asian vultures are recognized as Old World vultures (family Accipitridae, subfamily Aegypiinae). There are 15 species of Old World Vultures and 7 Species of New World Vultures.

What is a buzzard?

In the U.S. vultures are often called "buzzards," but in actually a buzzard is a European member of the hawk family. The European buzzard, Buteo buteo, is closely related to the American red tailed hawk.

Almost all the vultures you see in the U.S. are Turkey Vultures. Black Vultures also exist in the South, but they do not have the graceful flight of the Turkey Vulture and are not as common. California Condors (a type of vulture) have been retintroduced in California and Arizona, but are so rare you are unlikely to see one in your entire life unless you make a special trip to the remote areas where they have been released.

Turkey Vultures got their name from their bald red heads. The lack of feathers on their head are an adaptive mechanism -- when a vulture is eating a dead animal, it often sticks its head inside the carcass to reach the meat. Feathers on the head would trap unwanted flesh and blood, along with bacteria. A bald head, then, is an adaptive mechanism for cleanliness, as is the vulture's habit of urinating down its own legs -- another way to clean off clinging bits of flesh and bacteria.

Turkey Vultures have few predators, other than man. Their nests are scratched out of bare patches of soil on cliff faces and out of the rotting wood at the tops of broken trees. They will often nest in the sides of abandoned farm buildings as well -- old silos being a favorite location. Vulture nests are subject to predation by raccoons, but the vulture as a fairly effective defensive mechanism -- it vomits up a large masses of semi-digested meat along with very acidic digestive juices. The smell of Turkey Vulture Vomit is rather astounding, and the stomach acid is acidic enough to burn a raccoon's eyes.

You will rarely see Turkey Vulture flying in the early morning, as they launch themselves from trees, cliffs, powerlines, barns and silos only after the morning air has warmed up. A Vulture will fly into a thermal uplift, ride it up in a wide circle, and then glide across the sky at speeds of up to 50 miles per hour gently falling until they reach the next thermal which they in turn ride up again -- repeating the process adinfinitum. On a good day, a Turkey Vulture can glide for four of five hours without flapping its wings.

The feet of a Turkey Vulture are very weak and are built a bit like a chicken's -- they cannot catch small prey like a rabbit. Road kill is their primary food source, and the rise in deer, raccoon, possum and groundhog populations has meant a rise in turkey vultures. Vultures are also common on river banks where they scavenge washed-up fish.


retrieverman said...

New World vultures aren't even closely related to hawks, eagles, the real buzzards (there's a species called a honey buzzard that you should check out), Old World Vultures, and falcons.

Their closest relatives are storks.

The reason why they look like Old World Vultures is because of convergent evolution.

Turkey vultures are harmless and helpful. They have a wonderful sense of smell.

For most of my life they have been the only vulture species native to my neck of the woods, but in recent years, the predatory American black vulture has moved north.

This vulture occasionally kills small livestock.

And it's got the paranoid up in arms.

People are now wanting to shoot black vultures, illegally.

They can can get permits under the Migratory Bird Treaty's provisions, but what will happen when news outlets keep reporting unbalanced stories like this is both species of vulture will be victims. Juvenile turkey vultures have black heads, and the average person has never seen a black vulture and has nothing on which to base the differences.

I've seen both. It's really easy to tell them apart.

However, that doesn't mean that people won't be shooting them illegally because of the lack of balance provided in the media about them.

Seahorse said...

Driving through St. Mary's County, MD today I saw a large bird on the side of the road I took for a vulture. The striking thing was that it was completely black, to include a very black beak. I'm used to seeing vultures pretty much daily, but this one was different. I wonder if he was a "southern" vulture come a bit more northery? Funny you should write this post as only Saturday morning my students and I were having a conversation about vultures, and among other things how persecuted they are when new development moves into a vulture's ancestral area. Don't people realize what a stinky, nasty world we'd have without these scavengers? Not to mention the "they were here first" aspect of fairness.


Bungalow Jo said...

Some 20 years ago there were reports of the black vulture edging northward; the hypothesis at the time was the proliferation of landfill pickin's, from which the more aggrassive black vultures could drive off the gulls.

On my way into Annapolis each morning, I see mostly black vultures, soaring over the fields and woods. There is a small "family" of turkey vultures closer to my home who perch atop the highway light poles to bask in the rising sun's rays.

Donna said...

I love me some TVs. They're highly personable with and fun to work with for those who do rehab. Mischievous, too. Unlike raptors, their feet are harmless but they have excellent aim with their bills and will stab, grab and twist human flesh into purple pain just fun. Can't blame them, after all we've done to demonize them.

I've read that gas companies look for TV kettles to help them pinpoint gas leaks, but have never seen it in action or been able to confirm it.

PipedreamFarm said...

Over the past 15 years were have lived along the slopes of the Blue Ridge Mts in MD. Over those years we have mostly seen black vultures. Our previous farm (close to Harpers Ferry) had a winter roost of black vultures in the pines. One day there were 20-50 vultures soring/circling over our house. A couple of years back a local farm lost a cow and calf due to black vulture predation; the vultures had pecked the half born calf and the cow's uterus killing the calf and damaging the cow beyond saving.

PipedreamFarm said...

We've seen our Maremma Sheepdog run off the vultures that are near the cows at calving time and near the ewes at lambing time.