Editing Hibernation (section)

===Facultative hibernation===
Facultative hibernators enter hibernation only when either cold-stressed, food-deprived, or both, unlike obligate hibernators, who enter hibernation based on seasonal timing cues rather than as a response to [[stressors]] from the environment.

A [[chipmunk]], for example, is a facultative hibernator. Even though it sleeps for a long period of time, it is not a true obligate hibernator. This is because during the long period of sleep, its temperatures do not decrease to the low levels of hibernation. It only truly hibernates if food is scarce.<ref>{{cite book| title = Exploring Life Sciences| date = 2000| volume = 6|pages = 418–419|isbn = 0-7614-7141-3|publisher = Marshall Cavendish}}</ref>

A good example of the differences between these two types of hibernation can be seen in [[prairie dog]]s. The [[white-tailed prairie dog]] is an ''obligate'' hibernator, while the closely related [[black-tailed prairie dog]] is a ''facultative'' hibernator.<ref>{{cite journal |author1=Harlow, H.J. |author2=Frank, C.L. |year=2001 |title=The role of dietary fatty acids in the evolution of spontaneous and facultative hibernation patterns in prairie dogs |journal=J. Comp. Physiol. B |volume=171 |issue=1 |pages=77–84 |doi=10.1007/s003600000148 |pmid=11263729 |s2cid=25142419}}</ref>