National Geographic : 1968 May
just thrown down. The bird raised his head and once more threw the stone at the ostrich egg lying on the ground before him. It was true! We were watching that seldom recorded phenomenon-the use of a tool by an animal. And we were, as far as we know, the first scientifically qualified witnesses to this extraordinary talent of the Egyptian vulture. Gradually we sorted out the different vul tures. The company included the usual gath ering of white-backed vultures and Riippell's griffons, some hooded vultures, a few huge lappet-faced vultures, and just two of the small white Egyptian vultures. As we watched, the second Egyptian vul ture picked up a stone in his beak and moved toward an egg. With excellent aim the bird threw the stone with a forceful downward movement of head and neck. He pecked at the shell, as though feeling for a crack, then picked up the stone again and flung it. This time he missed the egg, but the third time he scored another hit. Three minutes later a di rect hit cracked the shell, and after a few more 632 throws, the vulture buried his beak in the rich, nutritious yolk as it spilled onto the ground. Three of the larger vultures immediately rushed in and drove the stone-thrower away. Others joined them, and soon the egg was lost beneath a mass of feathers. In a few moments there was nothing left save the broken shell and a damp patch on the earth. As for the provider of the feast, he was walking toward another egg, head in air, stone in beak. "Crack!"-the sound told us of the success of his first throw. No Other Species Seen Cracking Eggs We soon noted that only the Egyptian vul tures were able to fracture the ostrich eggs. Even the lappet-faced vultures, despite re peated efforts with their strong beaks, failed to crack the shells, which are a sixteenth of an inch thick and extremely tough. The two stone-throwers eventually opened all the eggs, though they never got more than a couple of beakfuls of food before their larg er cousins chased them away.