Researchers Argue It Was Gerbils, Not Rats, Spreading the Black Plague

Sounds like history teachers might owe rats a big apology this morning: A team of researchers is now arguing that they were not, in fact, guilty of spreading the devastating bubonic plague across medieval Europe. It’s just like My Cousin Vinny!

The BBC spoke to the University of Oslo’s Professor Nils Christian Stenseth, who just dropped a big study in the Proceedings of the National Academy of Sciences. He says the weather records from the period just don’t support the longstanding “rat reservoir” (vom) theory:

They compared tree-ring records from Europe with 7,711 historical plague outbreaks to see if the weather conditions would have been optimum for a rat-driven outbreak.

He said: “For this, you would need warm summers, with not too much precipitation. Dry but not too dry. And we have looked at the broad spectrum of climatic indices, and there is no relationship between the appearance of plague and the weather.”

Instead, his team proposes an alternate culprit, which is giant Asian gerbils: “We show that wherever there were good conditions for gerbils and fleas in central Asia, some years later the bacteria shows up in harbour cities in Europe and then spreads across the continent.” And the Silk Road was particularly active at the time, providing a convenient superhighway for plague-ridden gerbils with a touch of wanderlust.

A compelling theory. However, it does sound like a classic move long practiced by defense attorneys: Some other dude did it. Somebody better make sure Stenseth isn’t in the employ of an Oslo-area rat king.