Intelligent, road-kill loving turkey vultures entertaining state parks visitors

Posted December 13, 2012 at 11:02 am



Roosting turkey buzzards 3 cc .tif

Turkey buzzard 3 cc.tif

by Tom Uhlenbrock

Missouri State Parks

Four birders on an outing last December to Ha Ha Tonka State Park focused their binoculars on a green tag attached to the wing of one of 28 roosting turkey vultures. The tag said E43.

They reported their finding to the Bird Banding Laboratory operated by the U.S. Geological Survey. The center said the tag was attached to the bird in August 2011 in Saskatchewan, Canada, when it was too young to fly.

Although not yet a year old when spotted at Ha Ha Tonka, the young turkey vulture had flown nearly 1,200 miles to get to the park on the Lake of the Ozarks in central Missouri. Ha Ha Tonka State Park is one of several state parks in Missouri where flocks of vultures roost in winter.

The long-distance flight was not a surprise to Edge Wade, a self-proclaimed “birding bum” from Columbia, Mo., who was among the four birders. She is an admirer of the species that she affectionately referred to as “nature’s garbage collectors.”

“I love them,” Wade said of turkey vultures. “They clean up a lot of our messes.”

With red crinkly skin on a bald head and dark plumage, turkey vultures would finish last in any birding beauty contest. But they are marvelously adapted for their job of finding and eating rotting carrion, including road kill.

With a digestive system that renders toxins harmless, a turkey vulture can dine on a diseased carcass, and come back for seconds.

“They’re ugly from our perspective,” said Wade, “but the bare skin is a natural way for them to keep clean. When they relieve themselves, the urine runs down their legs and has a chemical in it that reduces the possibility of infection. Their digestive system is able to handle stuff that would kill a human.”

They have no syrinx, the vocal organ of birds, but sometimes grunt or hiss when disturbed. The pink feet are flat, and relatively weak, giving it an ungainly, hopping walk. The beak is short, hooked and whitish; the nostrils are perforated.

In another unsavory, but effective, trait, a turkey vulture that has just gorged on a meal will disgorge it just as fast at an approaching predator. The practice allows the vulture to lighten itself for a quick takeoff, and also distracts the predator with a stream of acidic digestive juices.

“And they’re one of the few birds to have a sense of smell, which they use for finding carcasses,” Wade said. “Turkey vultures love to sit on the superstructures of oil refineries where gases are coming off. It must smell like a gourmet restaurant to them.”

Trout parks attract vultures

Wade, who is retired, is a member of the Audubon Society of Missouri and helped set up its website at mobirds.org that tracks bird sightings listed by volunteers. SPARKS is the link for birding data at Missouri State Parks and CACHE has sightings at state conservation areas.

Data from the site has led birders to conclude that turkey vultures, like other species, are spending their winters farther north, most likely because of climate change.

“Fifteen years ago, there were no turkey vultures in Columbia in winter,” Wade said. “Now, routinely they’re here throughout the winter. Black vultures, the other species in Missouri, also are moving north. They’ve really been expanding in the last three to five years.”

Black vultures, which have black skin on their heads, have shorter wings and tails than turkey vultures. Turkey vultures are common across Missouri in summer; they usually are found south of the Missouri River in winter. Black vultures normally are found in the southernmost counties of the state.

Large numbers of vultures congregate in Missouri state parks in winter, especially at the three popular trout parks – Montauk, Bennett Spring and Roaring River, which is the farthest south and gets more black vultures. Other state parks with wintering vultures include Rock Bridge Memorial, Trail of Tears, Cuivre River, Lake of the Ozarks and, of course, Ha Ha Tonka.

Turkey vultures are opportunistic flyers. They are fond of bluffs next to a body of water where warm thermals rising in the morning help them gain loft. They can circle for hours, maneuvering with the slightest tilt of their 6-foot wings in a teetering flight pattern. They stretch their wings in a horizontal V when flying, revealing gray or silvery feathers on the undersides along the trailing edge and wingtips.

“Like everybody else, they take the path of least resistance,” Wade said. “They like to be near water so they can take the warm thermals up and soar.”

Real intelligent birds

Hundreds of turkey vultures were roosting in a valley of tall sycamores on a late afternoon drive through Montauk State Park near Salem in mid-November. On a return visit to the same spot barely an hour later, every bird had disappeared, like ghosts in the night.

“That’s weird,” said Steve Bost, the park’s interpretive resource specialist, who was along for the ride. “Where’d they all go?”

The disappearing act is just one reason why Bost, too, is an admirer of the species. He gives nature talks on turkey vultures to park visitors in a program titled “Roadkill Café.”

“We have one of the largest roosting flocks I’ve seen anywhere – somewhere between 250 and 400 birds,” Bost said. “This is my eighth year here, and the flock just keeps growing. They’ll circle over the park in the evening; they’ll cover the whole sky.”

Bost figures that the vultures like the park because it’s safe – “They won’t get shot here” – and the release of trout occasionally results in a fish carcass waiting in the morning. It is illegal to harm turkey vultures inside or outside of state parks; they are protected by the Migratory Bird Treaty Act of 1918.

“They won’t win any awards for looks,” Bost said. “But they’re a real intelligent bird.

“I talked to a woman who does rehab work with owls, hawks and eagles. She said they got a turkey vulture in and, in a couple of days, it did more tricks and bonded quicker than any other bird she ever had. It would follow her around and untie her shoes.”

The public is asked to report bird bands to reportband.gov. For more information, visit mostateparks.com. Missouri State Parks is a division of the Department of Natural Resources.