Missouri's Other Vulture
Two species of vultures reside in Missouri, the black and the turkey. The turkey vulture, sometimes called a buzzard, is common throughout the state. The black vulture is lesser known and occurs only in the most southern counties of Missouri.
Black vultures look like a smaller version of their red-headed kin. In fact, black vultures are sometimes mistaken for young turkey vultures. Black vultures grow to about 25 inches long, have 5-foot wingspans and weigh nearly 4.5 pounds. The naked head of a black vulture is, as you might expect, black.
The only parts of its body that aren't black are whitish patches on the outer edge of each wing. The black vulture's tail is broad and rather short for a creature of such size, and its feet extend nearly to the end of the tail. In flight the tail looks as if it blends right into the wings, giving the bird a compact appearance.
By contrast, turkey vultures have red heads as adults, with the immature vulture's head being a rather dull grayish-brown. An adult turkey vulture can grow to about 27 inches long, have a 6-foot wingspan and weigh up to 5.5 pounds. Their tails extend well beyond the feet and seem to balance the size of the body. A good view of the underside of the wings reveals a light band that runs from the body to the tips of the primaries.
The flight of each bird is unique, as well. The turkey vulture's flight is lazy, almost mesmerizing, with few flaps of the wings. The wings are kept in a V-shape with the tips higher than the body as the bird sails, swaying side to side. Black vultures seem to work harder at flying, with heavy flaps of the wings interspersed with short glides. The wings are held horizontal to the body, giving the bird a flatter flight profile.
It was thought that the black vulture inhabited only southeast Missouri, and even then was not considered common. Not until 1986 were black vultures documented in the Tri-Lakes area of southwest Missouri in any number, due in part to the work of Dr. Jane Fitzgerald of Reeds Spring and Patrick Mahnkey of Forsyth.
Fitzgerald and Mahnkey observed black vultures roosting with turkey vultures in southwest Missouri. Black vultures may have always occurred there but were apparently overlooked.
Where the ranges of the two vultures overlap, the two species accommodate each other, even roosting in the same area or tree, but in small segregated flocks. According to Fitzgerald, when these small groups settle in for the night, they may fight among themselves as to who gets which branch, but a turkey vulture won't fight a black, and a black won't go up against a turkey vulture.
Even though most folks find the birds repugnant, vultures fill an important niche in nature. They are the clean-up crew. This lifestyle demands certain adaptations.
A major adaptation is food. Carrion, or dead matter, makes up most of both vultures' diets. But black vultures may include newborn animals, chicks and eggs in their menu. They will also eat grass and vegetable matter.
Most other animals would get sick from eating carrion, possibly contracting botulism, a disease that attacks the nerve muscle junctions, then leads to paralysis and death. But it doesn't bother the vultures. By ridding the natural world of dead animals, vultures keep botulism in check.
Vultures also display an adaptation to conserve energy. To slow down its metabolic rate, which in turn saves calories, the vulture's body temperature may drop by up to 4 degrees at night.
This is where the black feathers of the vulture come in handy. By spreading their wings in sunlight, the feathers soak up the sun's heat, warming the bird.
Urohydrosis also helps the vultures save energy. A discussion of this behavior, however, is not for the faint of stomach. All birds lack sweat glands, so they can not expel sweat through their skin. And, to make things worse, they have no separate urinary tract. So, vultures defecate a mixture of uric acid and feces onto their legs and feet. This mixture evaporates, in turn cooling the bird. The uric acid also eliminates parasites that the bird may have contracted from the carrion it feeds on.
Studies reveal that turkey vultures have a keen sense of smell, while black vultures do not. Black vultures locate food by sight.
Vultures lack a syrinx, or voice box, so they can't sing, twitter or chatter like other birds. Instead, communication comes through hisses, grunts or body posture.
Neither vulture has strong legs or feet. When they roost on a tree branch, they settle into a squatting position, rather than standing on a foot like most birds. Black vultures spend more time on the ground than turkey vultures. And, blacks don't seem to scare as easily, allowing bird watchers to get fairly close.
Vulture parents don't go in for coziness. They don't even build a nest. But, they do enjoy a little home decorating, placing pieces of brightly colored glass, bottle tops and other items in the nest area. And unlike the more solitary turkey vulture, several black vultures may nest together.
The preferred area for laying eggs is open terrain with woodlands or thickets, where one to three dull-white to gray-green dark blotched eggs are laid on the bare ground at the base of a stump, in caves or under boulders. The chicks hatch in 38 to 41 days, and then are fed through regurgitation.
Vultures have long been associated with witches, witchcraft and death. Some recent behavior may perpetuate this association. On several occasions black and turkey vultures have ransacked a small family cemetery in Taney County. The frolicking birds picked apart artificial flowers and dragged a bouquet across the ground. And, of course, the vultures left behind a whitewashing of the tombstones.
One of the largest concentrations of vultures in southwest Missouri is in a roost near Shepherd of the Hills Fish Hatchery, just outside of Branson. From early fall to spring, hundreds of vultures, both blacks and turkeys, arrive to roost in this area, filling the branches of lakeside sycamores.
Only the pulsing foof! foof! of the large bird's wings tell of the arrival of the vultures to the roost. In the dying light of the evening, the sight and sound create an eerie atmosphere of gloom.
On February 10, 1996, for the first time, the Shepherd of the Hills Visitor Center will host Vulture Venture, from 10 a.m. to 3:00 p.m. You'll be able to see the vultures as they ride the air currents above Table Rock Dam, or as they come in to roost. Learn interesting facts about vultures and how to identify them. Experts will be on hand to answer questions, programs will be offered every hour, and you can see a live vulture nose to beak.
The Shepherd of the Hills Fish Hatchery is located on Highway 165, some 4 miles south of Branson at Table Rock Dam. For information, call the Visitor Center at 417-334-4865.