Black-tailed prairie dogs are more widely distributed than the white-tailed prairie dog and can be found in the western Great Plains. Unlike their white-tailed counterparts, this prairie dog does not enter torpor at an ambient temperature of 7⁰C and midwinter photoperiods but instead remains active all winter long. This facultative hibernator only enters hibernation when they are food and water stressed during winter, but this torpor is for a shorter duration. Prairie dog species are considered facultative hibernators compared to obligate hibernating squirrels that have a larger number of their populations in hibernation and have longer durations of torpor states. A possible explanation as to why the black prairie dog does not hibernate is that they have a larger renal capacity that helps them endure water shortages of winter. These prairie dogs have the capacity to survive long durations of food and water shortages at normothermic temperatures. They can endure the loss of 40% of their initial weight over a 56 day period of food and water deprivation while maintain normal blood chemistry.