More than ever, it’s not easy being green. Hundreds of amphibians around the world have essentially turned into sexy zombies.
While the infection of the pathogen Batrachochytrium dendrobatidis is a pretty horrible affair itself, scientists have discovered a new aspect of the fungal disease that is right out of the The Walking Dead: A study published Tuesday in Biology Letters provides evidence that B.d. — also known as the chytrid fungus — can manipulate the behavior of the animal to ensure its spread by making the frogs act like zombies: Alive but powerlessly working toward the annihilation of their kin.
Here’s how it works: The pathogen spreads through the population via something every animal wants — sex. The amphibians studied in this instance were 42 Japanese tree frogs. This species have been known to be infected but haven’t been dying off like other populations. In the summer of 2011 the team from Seoul National University recorded the mating calls of the male tree frogs, assessed if the frogs were infected, and then analyzed the call properties of the males.
To hear the difference between the calls of healthy and unhealthy male frogs, you can listen here.
Of the 42 frogs, nine were positive for B.d. These males were not only larger than uninfected males — their calls were louder and more rapid. These calls are known for attracting female frogs, meaning these frogs were having more sex.
More sex = more infections.
The infection is a brutal process. It takes over the skin cells of the amphibian, causes the skin to thicken, and stops the electrolyte transport process. This eventually causes the amphibian to experience cardiac arrest and die.
The team behind this new study hopes that this knowledge could lead to a potential solution for B.d., which has been ravaging all varieties of amphibians. The fungal disease has been found in 700 species across six continents.
There is some good news though: scientists have made some progress in curing the infection. Recently a team of researchers cured several groups of toads on the Spanish island of Majorca, after six years of research. So there’s hope that we can finally stop the sex-inducing zombie fungus from wreaking further havoc on the frog populace.