After 8 centuries, Rats Exonerated in Spread of Black Death. It May Have Been Their Cute Cousins, the Gerbils

From the Washington Post:

After nearly eight centuries of accusations for spreading the bubonic plague, scientists say they have compelling evidence to exonerate the much-maligned black rat. In the process, they’ve identified a new culprit: gerbils.

It’s always the cute ones you have to watch out for, isn’t it?

According to a study published in the Proceedings of the National Academy of Sciences, climate data dating back to the 14th century contradicts the commonly held notion that European plague outbreaks were caused by a reservoir of disease-carrying fleas hosted by the continent’s rat population.

“For this, you would need warm summers, with not too much precipitation,” Nils Christian Stenseth, an author of the study, told the BBC. “… 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, the fearsome “Black Death,” as the epidemic was known, seemed curiously tied to the climate in Asia. Analysis of 15 tree-ring records, which document yearly weather conditions, shows that Europe always experienced plague outbreaks after central Asia had a wet spring followed by a warm summer — terrible conditions for black rats, but ideal for Asia’s gerbil population. Those sneaky rodents and their bacteria-ridden fleas then hitched a ride to Europe via the Silk Road, arriving on the continent a few years later to wreak epidemiological havoc....MORE