How long can a Vulture soar with out flapping its wings and how does it eat its prey?

Vulture and like birds (all birds do this)exploit pockets of rising warm air (thermals) to provide the energy they need for lift. This is why vultures (birds) 'circle', not only to remain in one location over something that might be good to eat, but also to stay within the area of the thermal they are using to gain height.