Mentions of the critically endangered Yangtze finless porpoise in ancient Chinese poetry have revealed missing information about the habitat of the world’s only freshwater porpoise

Over the last 1,400 years, populations of the Yangtze finless porpoise have dramatically declined in China. But intensive surveys of its range only span the last couple of decades, leaving lots of gaps in scientists’ knowledge of the species.

A study of 724 ancient poems has revealed how far the Yangtze finless porpoise once roamed within the mighty river, allowing scientists to see how far its range has contracted and when that occurred.