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 head. The historic range of the black-tailed prairie dog was from southern Saskatchewan to Chihuahua, Mexico, and included portions of Montana, North Dakota, South Dakota, Wyoming, Colorado, Nebraska, Kansas, Oklahoma, Texas, Arizona, and New Mexico. As of 2007, black-tailed prairie dogs occur across most of their historic range, excluding Arizona; however, their occupied acreage and populations are well below historic levels. Black-tailed prairie dogs are diurnal. Above-ground activity is reduced when rain or snow is falling and during days when the temperature exceeds 100 °F (38 °C). During the winter months, black-tailed prairie dogs do not fully hibernate. They continue