国家地理:鸵鸟蛋·豺狼·秃鹰

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.
现在我们在非洲大草原上。一只鸵鸟刚刚下了一个蛋，一只饥饿的豺狼瞄准了这只蛋，决定美餐一顿。但是，这只兴致勃勃的动物打错了算盘。这只蛋太大了，太滑了，总之对他来说什么都不利。这可是重达三磅的食物啊，它会一直都在这里的，对吗?当然，如果这只埃及秃鹰不介入的话。
这些秃鹰一直在盯这可以吃的豺狼保护着的鸵鸟蛋。鸵鸟蛋蛋白质非常丰富，而且秃鹰有非凡的策略可以知道硬壳里面的蛋。埃及秃鹰是世界上为数很少的懂得利用石头作为工具的鸟类之一。有些科学家感到，这只是经过高级进化的本能，而不是智慧。无论这是什么，只要管用就行了。秃鹰终于在鸵鸟蛋上凿了一个洞，可以使嘴巴伸进去。秃鹰的美餐比豺狼快了一步，但是还不能放松警惕。你看，在非洲大草原上，啃噬蛋壳的声音就像一个简短的新闻报道。一旦发出声音，其他猎食者也想分得一杯羹。
一只黄褐色的鹰跑来分享这顿美餐。但是一个更大的不速之客即将到来。看看这只垂头丧气的秃鹰。你想和这只鸟发生冲突吗?这只鸟大约六尺高，是非洲大草原上最大，最具攻击性的秃鹰。猎食的时候总是遵循这个严格的规律，体型最大的鸟得到战胜品。