Prairie dogs are serial killers of ground squirrel

摘要

It was thought to be just a small, furry grass-nibbler, but the white-tailed prairie dog has another life - as a serial killer. Some prairie dogs bite their ground squirrel neighbours to death on a regular basis, the first time that a mammalian herbivore has been seen killing other herbivores. Whats more, those who kill go on to produce more surviving offspring, improving their evolutionary fitness, say John Hoogland, a biologist at the University of Maryland Center for Environmental Science, and Charles Brown of the University of Tulsa, Oklahoma. The duo recorded 163 killings of the squirrels over six years in the Arapaho National Wildlife Refuge in Colorado.