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

Endemic to China's Yangtze River, the Yangtze finless porpoise is known for its intelligence and charismatic appearance; it looks like it has a perpetual smile on its face. To track how this critically endangered porpoise's habitat range has changed over time,

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.