their dusky black wings, turn their backs or faces to the sun and get down to some serious sunbathing.
An hour or so later--around 9 a.m. in mid-summer-- their body temperatures rise back to normal, and they begin to leave their morning perch. Alternately flapping and soaring higher and higher in ever widening circles, they rise on thermal air currents from the warming earth.
They soar like gliders, gracefully dipping this way and that with their wings outstretched in a horizontal V, and the feathers at their wing tips spread like the fingers of ballerinas. Using updrafts from the surrounding hills, they rise ever higher and ride the wind out of the valley. One soars away southward, quickly becoming a small black dot high in the distant sky. Four drift slowly eastward. Nine have disappeared above the white oaks above the house to the north. Others have left unnoticed. Their day has begun in earnest.
Although up to 50 percent of a turkey vulture's diet may consist of grass, leaves, seeds and other vegetable matter, turkey vultures prefer dead animals. While all vultures have keen eyesight, turkey vultures also have a keen sense of smell, helping them find the carcasses of animals concealed under tall grasses and forest canopies.
A turkey vulture's weak talons and beak won't allow it to dine on just any dead animal. The carcass needs to be aged a bit. Being the connoisseurs of carrion that they are, they can actually determine the age of a carcass by its smell while still in the air. Movie scenes of vultures in the old west circling prospective prey that is still moving--however slowly--is the stuff of fiction. Those vultures would have a long wait.
By comparison, black vultures have a weaker sense of smell, but they make up for it with an attitude. When food is scarce, they are content to let turkey vultures do the looking. When the turkey vultures find a suitable carcass, the black vultures move in and, like schoolyard bullies, go to the head of the line.
Whether first or last in line, both vultures are particularly well designed for eating carrion that has been properly aged. Their featherless heads, for example, are particularly well suited for delving into ripened carcasses.
Their digestive systems are also specially adapted for consuming rotting meat. Vultures sterilize their food in the process of digesting it, possibly killing