It's common knowledge that they eat dead meat. What isn't widely known is more than 50% of their diet comes from plant materials such as seeds, leaves and grass. In a recent study in Castro Valley and Livermore, vulture "pellets" were analyzed, and about 25% of its volume was from animal sources such as shrew, mole, squirrel, gopher, mouse, rat, rabbit, bird, reptile, insect, muskrat, opossum, racoon, skunk, badger, and coyote. These vultures provides an efficient cleaning service: the dead animals would have rotted on the ground and spread disease.