When a creature croaks, its natural defenses fail and tiny decomposers start digging in
within just five minutes.
To deter bigger carnivores in search of a meal, some feasting microbes produce toxins
like anthrax and botulinum, tiny doses of which are fatal to much of the animal kingdom.
Yet many scavengers get shoulder-deep in dead meat without seeming to suffer - and we’re
just beginning to understand how they do it.
Quality control is one of their earliest lines of defense.
Wolves and foxes have been known to pass up diseased reindeer carcasses in favor of prey
killed by other predators, although it’s not yet clear how they can tell the difference.
And, despite their reputation, spotted hyenas prefer to dine on fresh meat, minimizing their
contact with microbes.
But sometimes, severely rotten flesh is the only item on the menu.
And some scavengers, such as burying beetles and vultures, actually seek out putrid carrion
because it’s easier to detect, dig into, and defend.
To combat the microorganisms in these meals, the beetles smear carcasses with antimicrobial
slime before feeding.
Other scavengers prefer an after-dinner antibiotic.
Bearded vultures assault microbes with stomach acid that's ten times more acidic than our
own, and strong enough to corrode steel.
But some tenacious pathogens, including the ones that cause botulism and tetanus, make
it through this caustic cauldron and thrive in the intestines beyond.
We’re not sure how vultures survive their first few toxic exposures, but we know that
with each encounter, their immune systems churn out more and more antibodies, building
resistance to the toxins.
Socializing can also give scavengers an immune boost.
Hyenas and lions, for instance, likely pass small doses of germs around as they groom,
eat, and compete with each other, which may help build up group-wide immunity to toxins
like anthrax.
Similarly, we humans have established our own herd immunity through controlled exposure
to diseases like meningitis and smallpox - we call it vaccination.
But we have yet to beat botulism or anthrax, so perhaps we can scavenge some of these scavengers’
tricks – after all, we have more in common with them than we may like
to admit.