Editing Groundhog (section)

===Hibernation===
[[File:Baby groundhogs - 05-17-2020.jpg|thumb|Two baby groundhogs]]
Groundhogs are one of the few species that enter into true [[hibernation]], and often build a separate "winter burrow" for this purpose. This burrow is usually in a wooded or brushy area and is dug below the [[frost line]] and remains at a stable temperature well above freezing during the winter months. In most areas, groundhogs hibernate from October to March or April, but in more temperate areas, they may hibernate as little as three months.<ref name="rhodeisland">[http://www.dem.ri.gov/programs/bnatres/fishwild/pdf/woodchuck.pdf Woodchucks in Rhode Island] {{Webarchive|url=https://web.archive.org/web/20070412090734/http://www.dem.ri.gov/programs/bnatres/fishwild/pdf/woodchuc.pdf |date=April 12, 2007 }}. (PDF) dem.ri.gov. Retrieved on September 15, 2011.</ref> Groundhogs hibernate longer in northern latitudes than southern latitudes.<ref>{{Cite journal |last1=Zervanos |first1=Stam M. |last2=Maher |first2=Christine R. |last3=Waldvogel |first3=Jerry A. |last4=Florant |first4=Gregory L. |date=January 2010 |title=Latitudinal Differences in the Hibernation Characteristics of Woodchucks (Marmota monax ) |url=https://www.journals.uchicago.edu/doi/10.1086/648736 |journal=[[Physiological and Biochemical Zoology]] |language=en |volume=83 |issue=1 |pages=135–141 |doi=10.1086/648736 |pmid=19958172 |issn=1522-2152|url-access=subscription }}</ref><ref>{{cite web|website=berks.psu.edu|date=January 23, 2014|title=Professor sheds light on groundhog's shadowy behavior|url=https://berks.psu.edu/story/2398/2014/01/23/professor-sheds-light-groundhogs-shadowy-behavior|access-date=June 11, 2021|archive-date=June 11, 2021|archive-url=https://web.archive.org/web/20210611180103/https://berks.psu.edu/story/2398/2014/01/23/professor-sheds-light-groundhogs-shadowy-behavior|url-status=live}}</ref> To survive the winter, they are at their maximum weight shortly before entering hibernation.<ref name="ReferenceA">Woodchucks in Rhode Island, dem.ri.gov</ref> When the groundhog enters hibernation, there is a drop in body temperature to as low as {{convert|35|°F|°C|abbr=out}}, heart rate falls to 4–10 beats per minute and breathing rate falls to one breath every six minutes.<ref>{{Cite web|url=https://www.uwsp.edu/biology/VertebrateCollection/Pages/Vertebrates/Mammals%20of%20Wisconsin/Marmota%20monax/Marmota%20monax.aspx|title= Marmota monax - Vertebrate Collection &#124; UWSP|access-date=October 13, 2018|archive-date=October 13, 2018|archive-url=https://web.archive.org/web/20181013053816/https://www.uwsp.edu/biology/VertebrateCollection/Pages/Vertebrates/Mammals%20of%20Wisconsin/Marmota%20monax/Marmota%20monax.aspx|url-status=live}}</ref> During hibernation, they experience periods of torpor and arousal.<ref>Penn State news, January 22, 2014, ''Professor sheds light on groundhog's shadowy behavior ''</ref> Hibernating woodchucks lose as much as half their body weight by February.<ref>Groundhog Day facts and factoids, Cornell Chronicle, February 1, 1996</ref> They emerge from hibernation with some remaining body fat to live on until the warmer spring weather produces abundant plant materials for food.<ref name="ReferenceA"/> Males emerge from hibernation before females.<ref>{{cite journal|doi=10.2307/3504364|jstor=3504364|title=Marmota monax|last1=Kwiecinski|first1=Gary G.|journal=Mammalian Species|year=1998|issue=591|pages=1–8|doi-access=free}}</ref><ref name="Schoonmaker"/>{{rp|50}} Groundhogs are mostly [[diurnality|diurnal]] and are often active early in the morning or late afternoon.<ref>[http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=woodchuck Woodchuck] {{Webarchive|url=https://web.archive.org/web/20140421064626/http://web.extension.illinois.edu/wildlife/directory_show.cfm?species=woodchuck |date=April 21, 2014 }}, Illinois University</ref>