Turkey Vultures don't have the sharp, strong beaks with which to start feeding on a carcass. They wait for a coyote, fox, or hawk to start the process. (A good thing, as they prefer their food "aged".)
When Turkey Vultures gather, they most often circle in large clusters termed "kettles". These gatherings are more for keeping inside a natural hot-air current. (An updraft). The "lift" from the updraft keeps the Turkey Vultures from the flapping their wings to stay aloft.
Flapping uses a lot of energy, which in raptors can be overcome by seizing live prey. Since Turkey Vultures seldom take live prey, Turkey Vultures have to be patient, so they HATE to flap.
When a carcass is available, Turkey Vultures will gather overnight in the trees overlooking their stationary and intended meal. At the earliest rays of sunrise, only then, will they start dining. It is sometimes comical to see Turkey Vultures who can't get airborne because of overfeeding: If they go anywhere, they have to hop!
Florida's superheated roadways generate "micro-updrafts": Some Turkey Vultures are seen soaring very low. When I've been out on a walk, some have nearly collided with me
—at knee-level! 