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Bloodthirsty monster or mangy coyote?

U. MICHIGAN (US) — Tales of the fearsome chupacabras, also known as the goatsuckers, surface around Halloween each year, but scientists say the dreaded monsters actually are coyotes with extreme cases of mange.

Livestock attacks in Puerto Rico, where dead sheep were discovered with puncture wounds, completely drained of blood, led to reports of monsters on the prowl. Similar reports began accumulating from other locations in Latin America and the U.S.

Next came sightings of evil-looking animals, variously described as dog-like, rodent-like, or reptile-like, with long snouts, large fangs, leathery or scaly greenish-gray skin, and a nasty odor.

Scientists studied some of the chupacabras carcasses and concluded the creatures were coyotes with mange—a skin condition caused by mites burrowing under the skin. University of Michigan biologist Barry OConnor, who studies the mites that cause mange, has an idea why the tiny assailants affect wild coyotes so severely, turning them into atrocities.

In a recent “Monster Talk” podcast, OConnor explained that the mite responsible for the extreme hair loss seen in “chupacabras syndrome” is Sarcoptes scabiei, which also causes the itchy rash known as scabies in people.



When humans began domesticating animals, Sarcoptes scabiei found a whole new realm of potential victims. Domestic dogs, like humans, have played host to the mites long enough to evolve the ability to fight off mange, but when the condition spreads to wild members of the dog family—foxes, wolves, and coyotes—watch out.

“Whenever you have a new host-parasite association, it’s pretty nasty,” says OConnor, a professor of ecology and evolutionary biology. “It does a lot of damage, and mortality can be relatively high because that host species has not had any evolutionary history with the parasite, so it has not been able to evolve any defenses like we have.”




“Because these animals are greatly weakened, they’re going to have a hard time hunting,” OConnor says. “So they may be forced into attacking livestock because it’s easier than running down a rabbit or a deer.”

While the chupacabras have achieved legendary status, other wild animals can suffer just as much from the effects of mange mites, OConnor adds. In Australia, the mite is killing off wombats. “They presumably got the mites from dingoes, which got them from domestic dogs, which got them from us.”

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