Conversation original aired August 16, 2010

The Plague killed millions of Europeans in the middle ages. It’s still alive today. Although it rarely strikes humans, it has killed millions of prairie dogs in the last century in North America. Scientists have long wondered where the plague goes after a deadly outbreak. Some thought the disease lived on in the soil. But a new study finds the plague survives with the help of a tiny meat-eating creature called a grasshopper mouse.   Dan Salkeld is a biologist from Stanford; his research took place at the Pawnee National Grasslands east of Ft. Collins, Colorado.