How Do Vultures Feast on Rotting Flesh Without Getting Sick?
Vultures’ faces and large intestines are covered with bacteria that are toxic to most other creatures, but these birds of prey have evolved a strong gut that helps them not get sick from feasting on rotting flesh, according to research.
As bacteria decompose a dead body, they excrete toxic chemicals that make the carcass a perilous meal for most animals. But vultures often wait for decay to set in, giving them easy access to dead animals with tough skins.
Moreover, vultures will often pick at a dead animal through its back end that is, the anus — to get at the tasty entrails. Their diet may be filled with toxic bacteria and putrid feces, but vultures are apparently immune to these deadly microbes, the researchers said.
“On one hand, vultures have developed an extremely tough digestive system, which simply acts to destroy the majority of the dangerous bacteria they ingest and on the other hand, vultures also appear to have developed a tolerance toward some of the deadly bacteria — species that would kill other animals actively seem to flourish in the vulture lower intestine.”
In the first analysis of bacteria living on vultures, researchers found that these scavengers are laden with flesh-degrading Fusobacteria and poisonous Clostridia. Both Clostridia and Fusobacteria appear to have adapted to the vultures’ harsh gut conditions, but may also help the birds by further breaking down nutrients, the researchers said.
The vultures’ bacterial similarities indicate that their digestive system has more influence on gut bacteria than diet does, the researchers said. The findings suggest the relationship between microbes and vulture digestion is more complicated than previously thought.