Prairie dog and Clark in 1804. Lewis described it in more detail in 1806, calling it the "barking squirrel". On average, these stout-bodied rodents will grow to be between long, including the short tail, and weigh between . Sexual dimorphism in body mass in the prairie dog varies 105 to 136% between the sexes. Among the species, black-tailed prairie dogs tend to be the least sexually dimorphic, and white-tailed prairie dogs tend to be the most sexually dimorphic. Sexual dimorphism peaks during weaning, when the females lose weight and the males start eating more, and is at its lowest when the females
Black-tailed prairie dog Infanticide partially or totally eliminated 39% (361 individuals) of all litters. Lactating females were the most common killers. Mortality of young was highest due to heavy predation during the winter and early spring following birth. Mortality increases with dispersal from a colony or coterie. Sylvatic plague, caused by the bacterium "Yersinia pestis", can quickly eliminate entire black-tailed prairie dog colonies. Once infected, death occurs within a few days. Black-tailed prairie dogs are also susceptible to diseases transmitted by introduced animals. The most common predators of black-tailed prairie dogs are coyotes ("Canis latrans"), American badgers ("Taxidea taxus"), bobcats ("Lynx rufus"), golden