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 mixed-grass prairie, sagebrush steppe, and desert grasslands. Shortgrass prairies dominated by buffalo grass ("Buchloe dactyloides"), blue grama ("Bouteloua gracilis"), and western wheatgrass ("Pascopyron smithii"), and mixed-grass prairies that have been grazed by native and non-native herbivores are their preferred habitat. Slopes of 2% to 5% and vegetation heights between 3 and 5 in (7–13 cm) are optimal for detecting predators and facilitating communication. In the Great Plains region, black-tailed prairie dog colonies commonly occur near rivers and creeks. Of 86 colonies located in Mellette County, South Dakota, 30 were located on benches or terraces adjacent to a creek or floodplain,