Dr Gerardo Ceballos is one of the world’s leading ecologists, and is a professor at the Institute of Ecology at National Autonomous University of Mexico. He is the author of numerous books, including The Skin of the Rainforest, Mammals of Mexico, and The Annihilation of Nature: Human Extinction of Birds and Mammals. He is also known for his fieldwork on prairie dogs, jaguars, and others. He proposed the first Mexican endangered species act, that includes roughly 4000 species of plants and animals in the country. He has seen through to establishment more than 20 protected areas that cover almost 2% of the Mexican land territory and protect thousands of plants and animals, including around 15% of all endangered species. No other Mexican scientist – perhaps no other individual scientist in the world — has accomplished so much in hands-on conservation. Today we talk about prairie dogs as a keystone species.