国家地理-2008-08-21 鸵鸟蛋·豺狼·秃鹰（在线收听）

Here we are on the Serengeti Plain in Africa, where an ostrich has abandoned an egg and a hungry jackal means to make a meal out of it. What we’ve got here is a highly motivated animal trying and failing to figure out this culinary conundrum. It’s just a little too big, a little too slippery, a little too everything for the jackal. There’s three pounds of food in there, and it’s gonna stay in there, right? Not if this Egyptian vulture has anything to do with it.

 These birds are always on the lookout for edible orbs in jackal-proof packaging. Ostrich eggs are an important source of protein, and this vulture has a strategy to get at its contents. The Egyptian vulture is one of the few birds in the world that figure out how to use a stone as a tool. Some scientists feel that this isn’t intelligence so much as highly evolved instinct. Whatever it is, it works. The vulture finally cracks a hole big enough for its beak. The vulture is one step closer to mealtime than the jackal, but it’s not home free yet. You see, here on the Serengeti, the sound of a cracked eggshell is like a newsflash. The word is out, and other diners are ready to line up.

 A tawny eagle shows up to share in the bounty. But an even bigger customer is about to appear. Check out this lappet-faced vulture. Would you wanna mess with this bird? At nearly four feet tall, it’s the largest, most aggressive vulture on the Serengeti. When it comes to a food find like this, pecking order is strictly observed. The biggest bird gets the booty.