Rats have been blamed for causing the bubonic plague throughout Europe for 800 years. We now know that they have been wrongly accused and the true culprit is the gerbil.
The plague was considerably more widespread when the climate was wet and warm, but Europe was neither wet nor warm when the worst bouts of plague sprouted. University of Oslo’s Nils Christian Stenseth has examined the data, and the evidence points towards wild gerbils causing the spread of the infamous black death.
A boom in the rodent population was to blame for increased cases of the disease, but the climate records for Europe didn’t tally up with the conditions necessary to increase the rat population. By studying tree rings, the research team found that the weather in Asia was somehow consistent with the pattern of disease spread in Europe.
Looking back, they found that rats couldn’t have transmitted the disease without being exposed to humid weather. Giant gerbils, native to central Asia, thrived when the weather was warm and there was a lot of water available. They hitched lifts to Europe along the ‘Silk Road’, the main trade passage between Asia and Europe. By the middle of the 14th century plague began to break out.
Rather than being transmitted by flea bites, the plague was airborne. It wiped out 100 million people, and broke out intermittently depending on the weather in Asia.