“…Our analyses, however, do not eliminate the possible existence of putative short- to medium-term reservoirs in the Mediterranean regions of Spain, Greece, Italy, and France, as well as in Central Europe in the 14th–17th centuries, and the Balkans in the 16th–19th centuries–as have been previously proposed ( 13 – 15 , 18 ). To appreciate how such putative European reservoirs might have existed for decades or even centuries, historians, archaeologists, soil scientists, and biologists need to collaborate to investigate other factors that sustained them ( 49 ). This will require exploring the complex relationships between European rodents, their fleas, and their ecologies, along with humans and their ectoparasites, as possible plague hosts and vectors after Y. pestis arrived in European ports from natural wildlife reservoirs in the East.…”