【英语时差8,16】为什么秃鹰不会食物中毒？（上）（在线收听）

Despite their ugly and morbid reputation, vultures play a critical role in keeping ecosystems healthy. These scavengers act as nature’s “clean up crew,” and prevent the spread of disease by consuming potentially infected carcasses. But how do vultures manage to eat diseased, rotting meat without getting sick? Their first line of defense is to avoid eating rotten meat. This may surprise you given the vulture’s reputation, but vultures prefer recently killed carcasses. They will happily chow down on two or three day old carrion, but once it really starts to rot, they avoid it. A second defense is a remarkable resistance to most diseases. Vultures can usually eat carcasses infected with such deadly pathogens as botulism, anthrax, cholera, and salmonella without getting sick.