Gerbils replace rats' as main cause of Black Death

Black rats may not have been to blame for numerous outbreaks of the bubonic plague across Europe, a study suggests. Scientists believe repeat epidemics of the Black Death, which arrived in Europe in the mid-14th Century, instead trace back to gerbils from Asia. Prof Nils Christian Stenseth, from the University of Oslo, said: "If we're right, we'll have to rewrite that part of history." The study is in the Proceedings of the National Academy of Sciences. The Black Death, which originated in Asia, arrived in Europe in 1347 and caused one of the deadliest outbreaks in human history. Over the next 400 years, epidemics broke out again and again, killing millions of people. It had been thought that black rats were responsible for allowing the plague to establish in Europe, with new outbreaks occurring when fleas jumped from infected rodents to humans. Rat reservoir However, Prof Stenseth and his colleagues do not think a rat reservoir was to blame. 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."READ MORE-http://www.bbc.co.uk/news/science-environment-31588671