Dean E. Biggins Travis M. Livieri Joshua J. Millspaugh David A. Eads 2013 We evaluated how American badgers (<i>Taxidea taxus</i>) might exert selective pressure on black-footed ferrets (<i>Mustela nigripes</i>) to develop antipredator defenses. In a colony of black-tailed prairie dogs (<i>Cynomys ludovicianus</i>) in South Dakota, badgers concentrated their activities where burrow openings and prairie dogs were abundant, a selective behavior that was exhibited by ferrets in the same colony. Badgers excavated burrows more often when in areas recently used by a ferret, suggesting that badgers hunt ferrets or steal prey from ferrets, or both. We also conducted an analysis of survival studies for ferrets and Siberian polecats (<i>M. eversmanii</i>) released onto prairie dog colonies. This polecat is the ferret's ecological equivalent but evolved without a digging predator. Badgers accounted for 30.0% of predation on polecats and 5.5% of predation on ferrets. In contrast, both polecats and ferrets have evolutionary experience with canids, providing a plausible explanation for the similar relative impact of coyotes (<i>Canis latrans</i>) on them (65.0% and 67.1% of predation, respectively). We hypothesize that ferrets and badgers coexist because ferrets are superior at exploitation competition and are efficient at avoiding badgers, and badgers are superior at interference competition. application/pdf 10.1644/12-MAMM-A-298.1 en American Society of Mammalogists American badgers selectively excavate burrows in areas used by black-footed ferrets: implications for predator avoidance article