View source for Groundhog

{{Short description|Species of rodent}}
{{Redirect|Woodchuck|other uses|Groundhog (disambiguation)|and|Woodchuck (disambiguation)}}
{{Redirect|Whistle Pig|the whiskey distillery|WhistlePig}}
{{Use mdy dates|date=February 2022}}
{{Speciesbox
| name = Groundhog
| status = LC
| status_system = IUCN3.1
| status_ref = <ref name=iucn>{{cite iucn|author=Cassola, F.|name-list-style=amp|year=2016|errata=2017|title=''Marmota monax''|article-number=e.T42458A115189992|doi=10.2305/IUCN.UK.2016-3.RLTS.T42458A22257685.en|access-date=19 February 2022}}</ref>
| image = Marmota monax UL 04.jpg
| image_caption = Groundhog at [[Laval University]] campus, [[Quebec City]], Canada
| genus = Marmota
| species = monax
| authority = ([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])
| synonyms = ''Mus monax'' {{small|Linnaeus,&nbsp;1758}}<br />
''Arctomys monax'' {{small|(Linnaeus,&nbsp;1758)}}
| subdivision_ranks = Subspecies
| subdivision = * ''M. m. monax'' <small>Linnaeus, 1758</small>
* ''M. m. canadensis'' <small>[[Johann Christian Polycarp Erxleben|Erxleben]], 1777</small>
* ''M. m. ignava'' <small>[[Outram Bangs|Bangs]], 1899</small>
* ''M. m. rufescens'' <small>[[Arthur Holmes Howell|A. H. Howell]], 1914</small>
| range_map = Marmota monax map.svg
| range_map_caption = Groundhog range in North America
}}

The '''groundhog''' ('''''Marmota monax'''''), also known as the '''woodchuck''', is a [[rodent]] of the family [[Sciuridae]], belonging to the group of large [[ground squirrel]]s known as [[marmot]]s.<ref name = MSW3>{{MSW3 Sciuridae | id = 12400961 | page = 802}}</ref> 
A lowland creature of North America, it is found through much of the [[Eastern United States]], across [[Canada]] and into [[Alaska]].<ref>{{cite web|publisher=Smithsonian National Museum of Natural History|work=North American Mammals|title=Marmota monax, Woodchuck|url=https://naturalhistory.si.edu/mna/image_info.cfm?species_id=146|access-date=February 20, 2018|archive-date=March 25, 2018|archive-url=https://web.archive.org/web/20180325073744/https://naturalhistory.si.edu/mna/image_info.cfm?species_id=146|url-status=live}}</ref> 
It was given its scientific name as ''Mus monax'' by [[Carl Linnaeus]] in 1758,<ref>{{Cite book|url=https://www.biodiversitylibrary.org/page/726959|title=Systema naturae|last=Linnaeus|first=Carl|year=1758|edition=10|volume=1|page=60|publisher=Lars Salvius|via=Biodiversity Heritage Library|access-date=January 29, 2018|archive-date=March 8, 2021|archive-url=https://web.archive.org/web/20210308080134/https://www.biodiversitylibrary.org/page/726959|url-status=live}}</ref> based on a description of the animal by [[George Edwards (naturalist)|George Edwards]], published in 1743.<ref>{{Cite book|url=https://www.biodiversitylibrary.org/page/50240862|title=A natural history of birds|last=Edwards|first=George|year=1743|edition=|volume=1|page=104|via=Biodiversity Heritage Library|access-date=December 11, 2024}}</ref>

The groundhog, being a lowland animal, is exceptional among marmots. Other marmots, such as the [[yellow-bellied marmot|yellow-bellied]] and [[hoary marmot]]s, live in rocky and mountainous areas. Groundhogs are considered one of the most [[Sociality#Presociality|solitary]] of [[Marmot|marmot species]]. They live in aggregations, and their social organization and long-term pair bonds varies across [[populations]]. The groundhog's male and female interactions are usually limited to the [[mating season]] and [[copulation (zoology)|copulation]]. However, certain populations of groundhogs have been observed to form long-term adult male-female association throughout the year, and often from year to year.<ref name="mating system">{{Cite journal |last1=Maher |first1=Christine R. |last2=Duron |first2=Melissa |date=June 16, 2010 |title=Mating system and paternity in woodchucks (Marmota monax) |journal=Journal of Mammalogy |volume=91 |issue=3 |pages=628–635 |doi=10.1644/09-MAMM-A-324.1 |s2cid=56472630 |doi-access=free}}</ref><ref name=Kwiecinski>{{cite journal|first=Gary G.|last=Kwiecinski|title=Marmota monax|journal=Mammalian Species|issue=591|date=December 4, 1998|pages=1–8|doi=10.2307/3504364 |jstor=3504364 |s2cid=253945560 |doi-access=free}}</ref>

The groundhog is an important contributor to the maintenance of healthy soil in [[woodland]]s and [[plain]]s; as such, the species is considered a crucial [[habitat engineer]].<ref>{{Cite journal|title=Social organization of woodchucks (Marmota monax)|first=Paul T.|last=Meier|date=December 1, 1992|journal=Behavioral Ecology and Sociobiology|volume=31|issue=6|pages=393–400|via=Springer Link|doi=10.1007/BF00170606|bibcode=1992BEcoS..31..393M |s2cid=44244749}}</ref><ref>{{Cite journal|title=The effects of red fox scent on winter activity patterns of suburban wildlife: evaluating predator-prey interactions and the importance of groundhog burrows in promoting biodiversity|first1=Jeremy D.|last1=Pustilnik|first2=Jeremy B.|last2=Searle|first3=Paul D.|last3=Curtis|journal=[[Urban Ecosystems]]|year=2021|volume=24|issue=3|pages=529–547|via=Springer Link|doi=10.1007/s11252-020-01056-5|bibcode=2021UrbEc..24..529P |s2cid=224867974}}</ref><ref>{{Cite journal|title=Functional specialization in the forelimbs of two digging mammals: the American badger (Taxidea taxus) and groundhog (Marmota monax)|first1=Alexis Lee|last1=Moore|first2=Michael|last2=Butcher|date=May 18, 2011|journal=The FASEB Journal|volume=25|issue=S1|article-number=867.12|doi=10.1096/fasebj.25.1_supplement.867.12|s2cid=87167021 |doi-access=free}}</ref> The groundhog is an extremely [[intelligent]] animal, forming complex [[social networks]] and [[kinship]] with its young; it is capable of understanding [[social behavior]], [[Communication|communicating]] threats through [[whistling]], and working [[cooperatively]] to accomplish tasks such as [[burrowing]].<ref>{{Cite journal|url=https://www.jstor.org/stable/pdf/40295409.pdf|jstor=40295409|title=Genetic Relatedness and Space Use in a Behaviorally Flexible Species of Marmot, the Woodchuck (Marmota monax)|last=Maher|first=Christine R.|journal=Behavioral Ecology and Sociobiology|year=2009|volume=63|issue=6|pages=857–868|doi=10.1007/s00265-009-0726-5|bibcode=2009BEcoS..63..857M |s2cid=20892108|access-date=May 29, 2021|archive-date=May 10, 2022|archive-url=https://web.archive.org/web/20220510213201/https://www.jstor.org/stable/40295409|url-status=live}}</ref><ref>{{Cite journal|url=https://blumsteinlab.eeb.ucla.edu/wp-content/uploads/sites/104/2017/08/DanielBlumstein1998_AB.pdf|title=A test of the acoustic adaptation hypothesis in four species of marmots|first1=Janice C.|last1=Daniel|first2=Daniel T.|last2=Blumstein|journal=Animal Behaviour|year=1998|volume=56|issue=6|pages=1517–1528|location=Department of Systematics and Ecology, [[University of Kansas]]|publisher=The Association for the Study of Animal Behaviour|doi=10.1006/anbe.1998.0929|pmid=9933550|s2cid=37133587|access-date=May 29, 2021|archive-date=June 2, 2021|archive-url=https://web.archive.org/web/20210602212601/https://blumsteinlab.eeb.ucla.edu/wp-content/uploads/sites/104/2017/08/DanielBlumstein1998_AB.pdf|url-status=live}}</ref>

==Etymology==
Common names for the groundhog include '''chuck''', '''wood-chuck''', '''groundpig''', '''whistle-pig''',<ref name="si">{{cite web |author=<!--Staff writer(s); no by-line.--> |title=''Marmota monax'' |url=http://www.mnh.si.edu/mna/image_info.cfm?species_id=146 |url-status=live |archive-url=https://web.archive.org/web/20160122132702/http://www.mnh.si.edu/mna/image_info.cfm?species_id=146 |archive-date=January 22, 2016 |access-date=February 1, 2015 |website=North American Mammals |publisher=Smithsonian Institution}}</ref> '''whistler''', '''thickwood badger''', '''Canada marmot''', '''monax''', '''moonack''', '''weenusk''', '''red monk''',<ref name="Seton1928">{{cite book|last1=Seton|first1=Ernest Thompson|year=1928|title=Lives of Game Animals|volume=IV|publisher=Doubleday, Doran & Company}}</ref>{{rp|300}} '''land beaver'''<ref>{{Cite web |last=Keck |first=Nina |date=December 17, 2020 |title=Where Do The Terms 'Woodchuck' And 'Flatlander' Come From? |url=https://www.vpr.org/post/where-do-terms-woodchuck-and-flatlander-come |url-status=live |archive-url=https://web.archive.org/web/20210125122508/https://www.vpr.org/post/where-do-terms-woodchuck-and-flatlander-come |archive-date=January 25, 2021 |access-date=February 2, 2021 |website=www.vpr.org |language=en}}</ref> and, among French Canadians in [[eastern Canada]], '''siffleux'''.<ref>{{cite web |title=La marmotte commune |url=http://www.hww.ca/fr/faune/mammiferes/la-marmotte-commune.html |archive-url=https://web.archive.org/web/20180805052150/http://www.hww.ca/fr/faune/mammiferes/la-marmotte-commune.html |archive-date=August 5, 2018 |work=Canadian Wildlife Federation - Faune et flore du pays |language=fr}}</ref> The name "thickwood badger" was given in the Northwest to distinguish the animal from the [[American badger|prairie badger]]. Monax ({{Lang|alg|Móonack}}) is an [[Algonquian languages|Algonquian]] name of the woodchuck, which means "digger" (cf. [[Delaware languages|Lenape]] {{Lang|del|monachgeu}}).<ref>{{cite journal |last=Chamberlain |first=Alexander F. |date=November 22, 2018 |title=Algonkian Words in American English: A Study in the Contact of the White Man and the Indian |journal=The Journal of American Folklore |volume=15 |issue=59 |pages=240–267 |doi=10.2307/533199 |jstor=533199}}</ref><ref name="Seton1928"/>{{rp|300–301}} Young groundhogs may be called chucklings.<ref name="Schoonmaker">{{cite book |last=Schoonmaker |first=W.J. |title=The World of the Woodchuck |publisher=J.B. Lippincott |year=1966 |isbn=978-1-135-54483-6 |ref=Schoonmaker}}</ref>{{rp|66}}

The etymology of the name ''woodchuck'' is unrelated to [[wood]] nor any sense of [[wikt:chuck|chucking]]. It stems from an [[Algonquian languages|Algonquian]] (possibly [[Narragansett (tribe)|Narragansett]]) name for the animal, ''wuchak''.<ref>{{cite web|url=http://animaldiversity.org/site/accounts/information/Marmota_monax.html|title=''Marmota monax'': Woodchuck|archive-url=https://web.archive.org/web/20150203032645/http://animaldiversity.org/site/accounts/information/Marmota_monax.html|archive-date=February 3, 2015|work=animaldiversity.com|access-date=February 24, 2015}}</ref> The similarity between the words has led to the popular [[tongue-twister]]:<ref>{{cite web|url=http://bussongs.com/songs/how_much_wood_would_a_woodchuck_chuck.php|title=Lyrics and Words for Children's Nursery Rhymes and Songs|archive-url=https://web.archive.org/web/20110726131619/http://bussongs.com/songs/how_much_wood_would_a_woodchuck_chuck.php|archive-date=July 26, 2011|work=BusSongs.com|access-date=September 15, 2011}}</ref>

:[[How much wood would a woodchuck chuck]]
::if a woodchuck could chuck wood?
:A woodchuck would chuck all the wood he could
::if a woodchuck could chuck wood!

==Description==
[[File:Marmota monax UL 03.jpg|thumb|Baby groundhog with its mother]]
The groundhog is the largest [[sciuridae|sciurid]] in its geographical range, excluding its presence in [[British Columbia]] where its range may be comparable to that of its somewhat larger cousin, the [[hoary marmot]]. Adults may measure from {{convert|41.8|to|68.5|cm|in|abbr=on|frac=16}} in total length, including a tail of {{convert|9.5|to|18.7|cm|in|abbr=on|frac=16}}.<ref name="Kwiecinski"/><ref name= Schwartz>{{cite book|last1=Schwartz|first1=C. W.|last2=Schwartz|first2=E. R.|year=2001|title=The wild mammals of Missouri|publisher=University of Missouri Press}}</ref><ref name=DC>{{cite book|title=Wildlife of Virginia and Maryland and Washington, D.C.|year=2003|author=Charles Fergus|page=45|publisher=Stackpole Books |isbn=978-0-8117-2821-8}}</ref> Weights of adult groundhogs typically fall between {{convert|2|and|6.3|kg|lboz|abbr=on}}.<ref name=DC/><ref>{{cite journal|last1=Ferron|first1=J.|last2=Ouellet|first2=J. P.|year=1991|title=Physical and behavioral postnatal development of woodchucks (''Marmota monax'')|journal=Canadian Journal of Zoology|volume=69|issue=4|pages=1040–1047|doi=10.1139/z91-149 |bibcode=1991CaJZ...69.1040F }}</ref><ref>{{cite journal|author1=Couser, W.|author2=Sargent, P.|author3=Brownhill, L. E.|author4=Benirschke, K.|year=1963|title=The somatic chromosomes of the Northeastern American woodchuck, Marmota monax|journal=Cytologia|volume=28|issue=1|pages=108–111|doi=10.1508/cytologia.28.108 |s2cid=84875225 |doi-access=free}}</ref>

[[File:Groundhog Newark, NJ 31 March 2021.jpg|thumb|left|Groundhog displaying its incisors]]
Male groundhogs are slightly larger than females on average and, like all marmots, they are considerably heavier during autumn (when engaged in [[Polyphagia|autumn hyperphagia]]) than when they emerge from hibernation in spring. Adult males average year-around weight {{convert|3.83|kg|lboz|abbr=on}}, with spring to fall average weights of {{convert|3.1|to|5.07|kg|lboz|abbr=on}} while females average {{convert|3.53|kg|lboz|abbr=on}}, with spring to fall averages of {{convert|3.08|to|4.8|kg|lboz|abbr=on}}.<ref name=Kwiecinski/><ref>{{citation|work=North Carolina Wild, Wildlife Profiles|title=Woodchuck, Marmota monax}}</ref> Seasonal weight changes reflect [[Circannual cycle|circannual]] deposition and use of fat. Groundhogs attain progressively higher weights each year for the first two or three years, after which weight plateaus.<ref name=Kwiecinski/>

Groundhogs have four [[incisor]]s, which grow {{convert|1.5|mm|in|frac=32}} per week. Constant usage wears them down by about that much each week.<ref>{{cite web|author=Leon M. Lederman Science Education Center|work=Fermilab Flora and Fauna Virtual Exhibit|title=Woodchuck|url=https://ed.fnal.gov/entry_exhibits/woodchuck/woodchuck.html|access-date=February 13, 2018|archive-date=August 9, 2017|archive-url=https://web.archive.org/web/20170809200709/http://ed.fnal.gov/entry_exhibits/woodchuck/woodchuck.html|url-status=live}}</ref> Unlike the incisors of many other rodents, the incisors of groundhogs are white to ivory-white.<ref>{{citation|work=Ohio DNR, ODNR Division of WILDLIFE|title=Woodchuck (Groundhog) -''Marmota monax''}}</ref><ref name="Schoonmaker"/>{{rp|20}} Groundhogs are well-adapted for digging, with powerful, short legs and broad, long claws. The groundhog's tail is shorter than that of other Sciuridae—only about one-fourth of body length.

==Distribution and habitat==
The groundhog dwells in lowland habitats, unlike other marmots that live in rocky and mountainous areas.  ''Marmota monax'' has a wide geographic range. The groundhog prefers open country and the edges of woodland, being rarely found far from a burrow entrance.<ref>{{cite journal |last1=Grizzell |first1=Roy A. |date=April 1955 |title=A Study of the Southern Woodchuck, Marmota monax monax |url=https://archive.org/details/sim_american-midland-naturalist_1955-04_53_2/page/n1 |journal=American Midland Naturalist |volume=53 |issue=2 |pages=257–293 |doi=10.2307/2422068 |jstor=2422068}}</ref> It can typically be found in small woodlots, low-elevation forests, fields and pastures, and hedgerows. It constructs dens in well-drained soil, and most groundhogs have summer and winter dens. Human activity has increased food access and abundance, allowing ''M. monax'' to thrive.<ref name=ADW>{{cite web|url=http://animaldiversity.org/accounts/Marmota_monax/|title=Marmota monax (woodchuck)|website=Animal Diversity Web|access-date=February 20, 2018|archive-date=February 20, 2018|archive-url=https://web.archive.org/web/20180220161438/http://animaldiversity.org/accounts/Marmota_monax/|url-status=live}}</ref>

==Behavior==
[[File:Groundhog-Standing2.jpg|thumb|A motionless individual, alert to danger, will whistle when alarmed to warn other groundhogs.]]
W.J. Schoonmaker reports that groundhogs may hide when they see, smell, or hear an observer.<ref name=Schoonmaker/>{{rp|41–43}} Marmot researcher Ken Armitage states that the social biology of the groundhog is poorly studied.<ref>Special feature "The Study of Groundhogs: A Real Life Look at Marmots", Movie "Groundhog Day" 15th Anniversary Edition.</ref>
Despite their heavy-bodied appearance, groundhogs are accomplished swimmers and occasionally climb trees when escaping predators or when they want to survey their surroundings.<ref name="chapman">{{cite book|last=Chapman|first=J. A.|author2=Feldhammer, G. A.|title=Wild Mammals of North America, Biology, Management, Economics|year=1982|publisher=Johns Hopkins University Press|isbn=0-8018-2353-6|url-access=registration|url=https://archive.org/details/wildmammalsofnor0000unse}}</ref> They prefer to retreat to their burrows when threatened; if the burrow is invaded, the groundhog tenaciously defends itself with its two large [[incisor]]s and front claws. Groundhogs are generally [[Agonistic behaviour|agonistic]] and territorial toward each other and may skirmish to establish dominance.<ref name="whitaker"/><ref name="Schoonmaker"/>{{rp|93}}
Outside their burrow, individuals are alert when not actively feeding. It is common to see one or more nearly motionless individuals standing erect on their hind feet watching for danger. When alarmed, they use a high-pitched whistle to warn the rest of the colony, hence the name "whistle-pig".<ref name="adweb" /><ref name="CWS">[https://web.archive.org/web/20110205231246/http://www.hww.ca/hww2.asp?pid=1&id=109&cid=8 Hinterland Who's Who ("Canadian Wildlife Service: Mammals: Woodchuck")]. Hww.ca. Retrieved on September 15, 2011.</ref> Groundhogs may squeal when fighting, seriously injured, or caught by a predator.<ref name="CWS"/> Other vocalizations include low barks and a sound produced by grinding their teeth.<ref name="CWS"/> [[David P. Barash]] wrote that he witnessed only two occasions of upright play-fighting among woodchucks and that the upright posture of play-fighting involves sustained physical contact between individuals that may require a degree of social tolerance virtually unknown in ''M. monax''. Alternatively, upright play-fighting may be a part of the woodchuck's behavioral repertoire that rarely is shown because of physical spacing and/or low social tolerance.<ref name="BarashMarmots">{{Cite book |last=Barash |first=David P. |title=Marmots: social behavior and ecology |date=1989 |publisher=Stanford University Press |isbn=978-0-8047-1534-8 |location=Stanford, California}}</ref>{{rp|97}}

===Diet===
[[File:Juvenile Groundhog in a Field of Clover.jpg|thumb|Clover is a preferred food source for groundhogs.]]
[[File:20240611 groundhog south meadows wm.webm|thumb|Eating wild vegetation]]
Mostly [[herbivory|herbivorous]], groundhogs eat primarily wild grasses and other vegetation, including berries, bark, leaves, and agricultural crops, when available.<ref name="whitaker">{{cite book|title=Mammals of the Eastern United States|last=Whitaker|first=John O|author2=Hamilton, W J.|year=1998|publisher=Cornell University Press|isbn=0-8014-3475-0|url-access=registration|url=https://archive.org/details/mammalsofeastern00whit}}</ref><ref name="auto">{{cite web | url=https://animaldiversity.org/accounts/Marmota_monax/ | title=Marmota monax (Woodchuck) | website=[[Animal Diversity Web]] }}</ref> In early spring, [[dandelion]] and [[Tussilago|coltsfoot]] are important groundhog food items. Some additional foods include [[sheep sorrel]], [[timothy-grass]], [[Ranunculus|buttercup]], [[persicaria]], [[agrimony]], red and black [[Raspberry|raspberries]], [[mulberries]], [[buckwheat]], [[Plantain cultivars|plantain]], [[wild lettuce]], [[alfalfa]], and all varieties of [[clover]]. Groundhogs also occasionally eat small animals, such as [[larva|grubs]], [[grasshopper]]s, [[snail]]s, and even bird eggs and baby birds, but are not as [[omnivore|omnivorous]] as many other [[squirrel|Sciuridae]].<ref name="auto"/><ref>Canadian Wildlife Federation, Groundhog</ref>

An adult groundhog can eat more than {{Convert|1|lb|kg|abbr=on}} of vegetation daily.<ref>DNR, Indiana Department of Natural Resources, Groundhog</ref> In early June, woodchucks' [[metabolism]] slows, and while their food intake decreases, their weight increases by as much as 100% as they produce fat deposits to sustain them during hibernation and late winter.<ref>{{Cite news |last=Line |first=Les |date=29 January 1997 |title=Woodchucks Are in the Lab, but Their Body Clocks Are Wild |url=https://www.nytimes.com/1997/01/28/science/woodchucks-are-in-the-lab-but-their-body-clocks-are-wild.html |work=The New York Times}}</ref> Instead of storing food, groundhogs stuff themselves to survive the winter without eating.<ref>Discovery Nature Encyclopedia, Groundhog</ref> Thought not to drink water, groundhogs are reported to obtain needed liquids from the juices of edible plants, aided by their sprinkling with rain or dew.<ref name="Schoonmaker"/>{{rp|85}}<ref>The Virtual Nature Trail at Penn State New Kensington Species Pages Scientific name: Marmota monax Common name: woodchuck.</ref><ref name="Seton1928"/>{{rp|308}}

===Burrows===
[[File:Marmota monax UL 07.jpg|thumb|Groundhog gathering nesting material for its warm [[burrow]]]]
Groundhogs are excellent burrowers, using burrows for sleeping, rearing young, and [[hibernation|hibernating]]. Groundhog burrows usually have two to five entrances, providing groundhogs their primary means of escape from predators. The volume of earth removed from groundhog burrows in one study averaged {{convert|6|cuft|m3}} per den. The longest burrow measured {{convert|24|ft|m}} in addition to two short side galleries.<ref name="Schoonmaker"/>{{rp|108–109}}

Though groundhogs are the most solitary of the marmots, several individuals may occupy the same burrow.

Burrows can pose a serious threat to agricultural and residential development by damaging farm machinery and even undermining building foundations.<ref name="adweb">{{cite web |last=Light |first=Jessica E. |title=Animal Diversity Web: Marmota monax |url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Marmota_monax.html |archive-url=https://web.archive.org/web/20110518042717/http://animaldiversity.ummz.umich.edu/site/accounts/information/Marmota_monax.html |archive-date=May 18, 2011 |access-date=July 14, 2009 |publisher=University of Michigan Museum of Zoology}}</ref> In a June 7, 2009, Humane Society of the United States article, "How to Humanely Chuck a Woodchuck Out of Your Yard" by John Griffin, director of Humane Wildlife Services, stated you would have to have a lot of woodchucks working over a lot of years to create tunnel systems that would pose any risk to a structure.{{citation needed|date=May 2024}}

The burrow is used for safety, retreat in bad weather, hibernating, sleeping, mating, and nursery. In addition to the nest, there is an excrement chamber. The hibernation or nest chamber is lined with dead leaves and dried grasses.<ref>{{Cite journal |last=Kwiecinski |first=Gary G. |date=1998-12-04 |title=Marmota monax |url=https://academic.oup.com/mspecies/article-lookup/doi/10.2307/3504364 |journal=Mammalian Species |issue=591 |pages=1–8 |doi=10.2307/3504364|jstor=3504364 }}</ref> The nest chamber may be about twenty inches to three feet ({{convert|20|-|36|in|cm|disp=out}}) below ground surface. It is about {{convert|16|in|cm}} wide and {{convert|14|in|cm}} high. There are typically two burrow openings or holes. One is the main entrance, the other a spy hole. Description of the length of the burrow often includes side galleries. Excluding side galleries, Schoonmaker reports the longest was {{convert|24|ft|m}}, and the average length of eleven dens was {{convert|14|ft|m}}.<ref name="Schoonmaker"/>{{rp|104–105}} W. H. Fisher investigated nine burrows, finding the deepest point {{convert|49|in|cm}} down. The longest, including side galleries, was {{height|ft=47|in=11.5}}.<ref name="Seton1928"/>{{rp|306}} Numbers of burrows per individual groundhog decrease with [[urbanization]].<ref>{{Cite journal |last1=Lehrer |first1=E.W. |last2=Schooley |first2=R.L. |last3=Whittington |first3=J.K. |date=2011-12-14 |title=Survival and antipredator behavior of woodchucks ( Marmota monax ) along an urban–agricultural gradient |url=http://www.nrcresearchpress.com/doi/10.1139/z11-107 |journal=[[Canadian Journal of Zoology]] |language=en |volume=90 |issue=1 |pages=12–21 |doi=10.1139/z11-107 |bibcode=2012CaJZ...90...12L |issn=0008-4301|url-access=subscription }}</ref>{{Failed verification|date=September 2025}}

Bachman mentioned when young groundhogs are a few months old, they prepare for separation, digging a number of holes in the area of their early home. Some of these holes were only a few feet deep and never occupied, but the numerous burrows gave the impression that groundhogs live in communities.<ref name="Seton1928"/>{{rp|318}}

Abandoned groundhog burrows benefit many other species by providing shelter. They are used by [[cottontail rabbit]]s, [[raccoon]]s, [[fox]]es, [[River Ottter|river otters]], [[eastern chipmunk]]s, and a wide variety of small mammals, snakes, and birds.<ref>{{cite web|url=https://njaes.rutgers.edu/e361/|title=Ecology and Management of the Groundhog (Marmota monax)|access-date=August 7, 2024}}</ref>

===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>

===Reproduction===
Groundhogs are considered the most [[Sociality#Presociality|solitary]] of the [[Marmot|marmot species]]. They live in aggregations, and their social organization also varies across [[populations]]. Groundhogs do not form stable, long-term pair bonds, and during [[mating season]] male-female interactions are limited to [[copulation (zoology)|copulation]]. Groundhogs in [[Ohio]], however, have been observed to have different social organization than groundhogs elsewhere, with adult males and females associating with each other throughout the year and often from year to year.<ref name="mating system"/><ref name="Kwiecinski" /> Usually groundhogs [[biological reproduction|breed]] in their second year, but a small proportion may breed in their first. The [[breeding season]] extends from early March to mid- or late April, after hibernation. Woodchucks are polygynous<ref name=ADW/> but only alpine and woodchuck marmot females have been shown to mate with multiple males.<ref name="mating system"/> A mated pair remains in the same den throughout the 31- to 32-day [[gestation period]].<ref>[https://web.archive.org/web/20100619014532/http://www.ncwildlife.org//Wildlife_Species_Con/Profiles/woodchuck.pdf Woodchuck. ''Marmota monax'']. (PDF). North Carolina Wildlife.</ref> As birth of the young approaches in April or May, the male leaves the den. One litter is produced annually. Female woodchucks give birth to one to nine offspring, with most litters ranging between 3 and 5 pups.<ref name=ADW/> Groundhog mothers introduce their young to the wild once their fur is grown in and they can see. At this time, if at all, the father groundhog comes back to the family.<ref name="Seton1928"/>{{rp|316}} By the end of August, the family breaks up; or at least, the larger number scatter, to burrow on their own.<ref name="Seton1928"/>{{rp|318}}

==Health and mortality==
[[File:Groundhog on alert.jpg|alt=A Groundhog in northern Ontario, Canada on high alert for predators.|thumb|A groundhog in northern Ontario, Canada on high alert for predators]]
In the wild, groundhogs can live up to six years with two or three being the average life expectancy. In captivity, groundhogs reportedly live up to 14 years. Human development often leaves vacant space near [[secondary forest]]s, which are indigenous to groundhogs, which ensures that groundhogs in well-developed areas are nearly free of predators other than [[humans]] (through various forms of pest control or [[Roadkill|vehicular incursion]]) or mid-to-large sized [[dogs]].<ref>{{cite journal|last1=Lehrer |first1=E. W.|last2=Schooley |first2=R. L.|last3=Whittington |first3=J. K. |title=Survival and antipredator behavior of woodchucks (''Marmota monax'') along an urban–agricultural gradient |journal=[[Canadian Journal of Zoology]]|date=2012 |volume=90 |issue=1 |pages=12–21 |doi=10.1139/z11-107|bibcode=2012CaJZ...90...12L }}</ref>

Occasionally, woodchucks may suffer from [[parasitism]], and a woodchuck may die from infestation or from bacteria transmitted by [[Disease vector|vectors]].<ref>{{cite book|title=The Wild Mammals of Wisconsin|last=Long|first=Charles A.|year=2008 |page=162|publisher=Pensoft Publishers |isbn=978-954-642-313-9}}</ref> In areas of intensive agriculture and the dairying regions of the state of Wisconsin, particularly in southern areas, the woodchuck had been almost extirpated by 1950.<ref name="Jackson1961">{{cite book|ref=Jackson|title=Mammals of Wisconsin|publisher=University of Wisconsin Press|last=Jackson|first=Hartley H. T.|year=1961|isbn=978-0-299-02150-4|url=https://books.google.com/books?id=qQfigtpJ11gC&q=woodchuck&pg=PA124}}</ref>{{rp|124}} Jackson (1961) suggested that exaggerated reports of damage done by the woodchuck led to excessive culling, substantially reducing its numbers in the state.

In some areas woodchucks are important [[game animals]] and are killed regularly for sport, food, or fur. In Kentucky, an estimated 267,500 specimens were taken annually from 1964 to 1971.<ref name="barbour">{{cite book|title=Mammals of Kentucky|first1=Roger W |last1=Barbour |first2=Wayne H |last2=Davis |publisher=University Press of Kentucky |isbn=0-8131-1314-8 |ol=5047309M|date=1974|pages=142–143|url=https://archive.org/details/mammalsofkentuck0000barb_p3x8/page/142/mode/2up}}</ref> Woodchucks had protected status in the state of Wisconsin<ref>{{cite web|url=https://dnr.wi.gov/topic/endangeredresources/laws.html|title=Wisconsin's endangered and threatened species laws|publisher=Wisconsin Department of Natural Resources|access-date=April 25, 2018|archive-date=April 26, 2018|archive-url=https://web.archive.org/web/20180426080318/https://dnr.wi.gov/topic/endangeredresources/laws.html|url-status=live}}</ref> until 2017.<ref>{{cite news|title=Wisconsin Gov. Walker signs woodchuck hunting bill|work=Chicago Tribune|date=November 13, 2017}}</ref> Woodchuck numbers appear to have decreased in Illinois.<ref>{{cite web|publisher=[[Illinois Department of Natural Resources]]|date=July 2008|title=The Creature That Keeps Digging|first=Kari|last=Thornton|page=20|url=https://www2.illinois.gov/dnr/OI/Documents/July08Groundhog.pdf|website=OutdoorIllinois Online|access-date=January 27, 2023|archive-date=December 27, 2021|archive-url=https://web.archive.org/web/20211227145354/https://www2.illinois.gov/dnr/OI/Documents/July08Groundhog.pdf}}</ref>

===Natural predators===
[[File:Woodchuck up a tree.jpg|thumb|Groundhogs can climb trees to escape predators.]]

Wild predators of adult groundhogs in most of eastern North America include [[coyote]]s, [[American badger|badgers]],<ref>{{Cite web|url=http://www.ontariobadgers.org/biology.html|title=Badger Biology (Ontario Badgers)|website=www.ontariobadgers.org|access-date=July 22, 2019|archive-date=July 22, 2019|archive-url=https://web.archive.org/web/20190722230221/http://www.ontariobadgers.org/biology.html|url-status=live}}</ref> [[bobcat]]s, and [[foxes]] (largely [[red fox]]). Many of these predators are successful stealth stalkers that catch groundhogs by surprise before they can escape to their burrows; badgers likely hunt them by digging them out from their burrows. Coyotes in particular are sizable enough to overpower any groundhog with the latter being the third most significant prey species per a statewide study in [[Pennsylvania]].<ref>{{Cite journal |last1=Witmer, G. W. |last2=Pipas, M. J. |last3=Hayden, A. |year=1995 |title=Some observations on coyote food habits in Pennsylvania |journal=Journal of the Pennsylvania Academy of Science |volume=69 |issue=2 |pages=77–80 |jstor=44149042}}</ref><ref>{{cite journal|last=Gipson|first=P. S.|year=1974|title=Food habits of coyotes in Arkansas|journal=The Journal of Wildlife Management|volume=38|issue=4|pages=848–853|doi=10.2307/3800055 |jstor=3800055 }}</ref><ref>{{cite journal|last=Progulske|first=D. R.|year=1955|title=Game animals utilized as food by the bobcat in the southern Appalachians|url=https://archive.org/details/sim_journal-of-wildlife-management_1955-04_19_2/page/248|journal=The Journal of Wildlife Management|volume=19|issue=2|pages=249–253|doi=10.2307/3796859 |jstor=3796859 }}</ref><ref>{{cite journal|last1=Rose|first1=C.|last2=Prange|first2=S.|year=2015|title=Diet of the recovering Ohio bobcat (''Lynx rufus'') with a consideration of two subpopulations|journal=The American Midland Naturalist|volume=173|issue=2|pages=305–318|doi=10.1674/amid-173-02-305-317.1 |s2cid=86285187 }}</ref><ref>{{cite journal|last1=Hockman|first1=J. G.|last2=Chapman|first2=J. A.|year=1983|title=Comparative feeding habits of red foxes (''Vulpes vulpes'') and gray foxes (''Urocyon cinereoargenteus'') in Maryland|journal=American Midland Naturalist|volume=110 |issue=2 |pages=276–285|doi=10.2307/2425269 |jstor=2425269 }}</ref><ref>{{cite book|title=Wildlife of Pennsylvania|author1=Charles Fergus|author2=Amelia Hansen|year=2000 |page=43|publisher=Stackpole Books |isbn=978-0-8117-2899-7}}</ref>

Large predators such as the [[gray wolf]] and [[eastern cougar]] are likely [[extirpated]] in the east but still may hunt groundhogs on occasion in [[Canada]].<ref>{{cite journal|author1=Voigt, D. R.|author2=Kolenosky, G. B.|author3=Pimlott, D. H.|year=1976|title=Changes in summer foods of wolves in central Ontario|journal=The Journal of Wildlife Management|volume=40|issue=4|pages=663–668|doi=10.2307/3800561 |jstor=3800561 |doi-access=free}}</ref><ref>{{cite book|editor1=Bolgiano, C.|editor2=Roberts, J.|year=2005|title=The Eastern Cougar: Historic Accounts, Scientific Investigations, and New Evidence|publisher=Stackpole Books}}</ref> [[Golden eagle]]s can also prey on adult groundhogs, but seldom occur in the same range or in the same habitats as this marmot. Likewise, [[great horned owl]]s can reportedly, per Bent (1938), prey upon groundhogs but rarely do so, given the temporal differences in their behaviors.<ref>{{cite journal|last=Olendorff|first=R. R.|year=1976|title=The food habits of North American golden eagles|journal=American Midland Naturalist|volume=95 |issue=1 |pages=231–236|doi=10.2307/2424254 |jstor=2424254 }}</ref><ref name= Bent>{{cite journal|last=Bent|first=A. C.|year=1938|title=Life histories of North American birds of prey, Part 2|journal=U.S. National Museum Bulletin|volume=170|pages=295–357}}</ref>

Young groundhogs (usually those less than a couple months in age) may also be taken by the [[American mink]], and perhaps other small [[mustelid]]s, [[cat]]s, [[timber rattlesnake]]s, and [[hawks]]. [[Red-tailed hawk]]s can take groundhogs at least of up to the size of yearling juveniles and [[northern goshawk]]s can take them up to perhaps young adulthood in the spring.<ref name= Kwiecinski/><ref name= DC/><ref>{{cite journal|author1=Becker, T. E.|author2=Smith, D. G.|author3=Bosakowski, T.|year=2006|title=Habitat, food habits, and productivity of northern goshawks nesting in Connecticut|journal=Studies in Avian Biology|volume=31|pages=119–125 |url=https://sora.unm.edu/sites/default/files/SAB_031_2006%20P119-125_Habitat,%20Food%20Habits,%20and%20Productivity%20of%20Northern%20Goshawks%20Nesting%20in%20Connecticut_Trevor%20E.%20Becker,%20Dwight%20G.%20Smith,%20Thomas%20Bosakowski.pdf}}</ref><ref>{{cite journal|author1=Aschemeier, L. M.|author2=Maher, C. R.|year=2011|title=Eavesdropping of woodchucks (Marmota monax) and eastern chipmunks (Tamias striatus) on heterospecific alarm calls|journal=Journal of Mammalogy|volume=92|issue=3|pages=493–499|doi=10.1644/09-MAMM-A-322.1|doi-access=free}}</ref><ref>{{cite journal|last=George|first=W. G.|year=1974|title=Domestic cats as predators and factors in winter shortages of raptor prey|journal=The Wilson Bulletin|volume=86 |issue=4 |pages=384–396 |jstor=4160538 }}</ref>

Beyond their large size, groundhogs have several successful [[Anti-predator adaptation|anti-predator]] behaviors, such as concealing their burrows under trees in the winter months<ref>{{cite book|last1=Beer|first1=Amy-Jane|last2=Morris|first2=Pat|year=2004|title=Encyclopedia of North American Mammals: An Essential Guide to Mammals of North America|publisher=Thunder Bay Press|isbn=978-1-59223-191-1 |ol=9406434M|page=202|url=https://archive.org/details/encyclopediaofno0000beer/page/202/mode/2up}}</ref> and scaling trees to escape a threat.<ref name="barbour"/>

==Relationship with humans==
[[File:Daughter of miner with pet ground hog. Dixie Darby Fuel Company, Marne Mine, Lejunior, Harlan County, Kentucky. - NARA - 541297.jpg|thumb|upright=0.8|Daughter of a [[Lejunior, Kentucky]], coal miner with her pet groundhog (1946)]]
Both their diet and their habit of burrowing make groundhogs a serious source of nuisance around farms and gardens. They will eat many commonly grown vegetables. Extensive burrowing can undermine foundations.<ref name="adweb"/>

Very often, the dens of groundhogs provide homes for other animals, including [[skunk]]s, [[red fox]]es, and [[cottontail rabbit]]s. Foxes and skunks feed upon [[eastern meadow vole|field mice]], [[grasshopper]]s, [[beetle]]s, and other creatures that destroy farm crops. In aiding these animals, the groundhog indirectly helps the farmer. In addition to providing homes for itself and other animals, the groundhog aids in soil improvement by bringing [[subsoil]] to the surface. The groundhog is also a valuable game animal and is considered a difficult sport when hunted in a fair manner.<ref name="Schoonmaker"/>{{rp|129–131}} In some parts of the U.S., they have been eaten.<ref name="Castro">{{cite web|last1=Castro|first1=Everett J.|title=Celebrate Groundhog Day With Groundhog Recipes|url=https://www.motherearthnews.com/real-food/groundhog-day-groundhog-recipes|website=Mother Earth News|date=January 1984|access-date=September 14, 2017|archive-date=December 6, 2018|archive-url=https://web.archive.org/web/20181206001549/https://www.motherearthnews.com/real-food/groundhog-day-groundhog-recipes|url-status=live}}</ref>

[[File:Grubby.png|thumb|upright=0.8|Groundhog during [[Groundhog Day]]]]
A report in 1883 by the New Hampshire Legislative Woodchuck Committee describes the groundhog's objectionable character:<ref name="Seton1928"/>{{rp|328}}<ref>{{cite journal |last1=Corning |first1=Charles R. |title=Report of the Woodchuck Committee |journal=Journals of the Honorable Senate and House of Representatives of the State of New Hampshire |date=June 1883 |volume=1883 |pages=1193–1197 |url=https://archive.org/details/journalsofhonora1883newh/page/1193/ |access-date=July 4, 2021}}</ref>

{{Blockquote|text=The woodchuck, despite its deformities both of mind and body, possesses some of the amenities of a higher civilization. It cleans its face after the manner of the squirrels, and licks its fur after the manner of a cat. Your committee is too wise, however, to be deceived by this purely superficial observation of better habits. Contemporaneous with the ark, the woodchuck has not made any material progress in social science, and it is now too late to reform the wayward sinner. The average age of the woodchuck is too long to please your committee.... The woodchuck is not only a nuisance, but also a bore. It burrows beneath the soil, and then chuckles to see a mowing machine, man and all, slump into one of these holes and disappear....|sign=|source=}}

[[File:Marmota monax-lateral.jpg|thumb|upright=0.8|Close encounter with a photographer at Sheldon Marsh State Nature Preserve, [[Ohio]]]]
Groundhogs may be raised in captivity, but their aggressive nature can pose problems. Doug Schwartz, a zookeeper and groundhog trainer at the [[Staten Island Zoo]], has been quoted as saying "They're known for their aggression, so you're starting from a hard place. His natural impulse is to [[Caedite eos. Novit enim Dominus qui sunt eius.|kill 'em all and let God sort 'em out]]. You have to work to produce the sweet and cuddly."<ref name="nytimes1">{{Cite news|first=Andy|last=Newman|url=https://www.nytimes.com/2007/01/12/nyregion/12groundhog.html?_r=1|title=Grooming a Weatherman for his TV Debut, and Hoping He Doesn't Bite The Host|periodical=[[The New York Times]]|date=December 1, 2007|access-date=February 22, 2017|archive-date=December 5, 2018|archive-url=https://web.archive.org/web/20181205193541/https://www.nytimes.com/2007/01/12/nyregion/12groundhog.html?_r=1|url-status=live}}</ref> Groundhogs cared for in [[wildlife rehabilitation]] that survive but cannot be returned to the wild may remain with their caregivers and become educational ambassadors.<ref>{{cite news|work=The Buffalo News|title=Sean Kirst: For Dunkirk Dave's caretaker, every day is Groundhog Day|date=February 1, 2018|url=http://buffalonews.com/2018/02/01/sean-kirst-for-dunkirk-daves-devoted-caretaker-every-day-is-groundhog-day/|access-date=February 20, 2018|archive-date=February 3, 2018|archive-url=https://web.archive.org/web/20180203064508/http://buffalonews.com/2018/02/01/sean-kirst-for-dunkirk-daves-devoted-caretaker-every-day-is-groundhog-day/|url-status=live}}</ref><ref>The Winchester Star, Christopher Early, 
"Library holds Groundhog Day celebration", p. 1A, February 6, 2017</ref><ref>Winchester Star, Centerpiece, "Local groundhog predicts 6 more weeks of winter", February 2, 2018, Cathy Kuehner</ref>

In the United States and Canada, the yearly [[Groundhog Day]] celebration on February 2 has given the groundhog recognition and popularity. The most popularly known of these groundhogs are [[Punxsutawney Phil]], [[Buckeye Chuck]], [[Wiarton Willie]], [[Shubenacadie Sam]], Jimmy the Groundhog, [[Dunkirk Dave]], and [[Staten Island Chuck]] kept as part of Groundhog Day festivities in [[Punxsutawney, Pennsylvania]]; [[Cleveland, Ohio]]; [[Wiarton, Ontario]]; [[Sun Prairie, Wisconsin]]; [[Dunkirk, New York]]; and [[Staten Island]] respectively. The 1993 comedy film ''[[Groundhog Day (film)|Groundhog Day]]'' references several events related to Groundhog Day, and portrays both Punxsutawney Phil himself, and the annual Groundhog Day ceremony. Famous [[Southern United States|Southern]] groundhogs include [[General Beauregard Lee]], based at [[Dauset Trails Nature Center]] outside [[Atlanta, Georgia]].<ref name="lee-ajc">{{cite news|last=Elder|first=Lane|website=[[The Atlanta Journal-Constitution]]|title=Groundhog Day is steeped in tradition but isn't the most accurate, according to weather almanacs|date=February 2, 2020|access-date=April 11, 2020|url=https://www.ajc.com/news/groundhog-meteorologists-predict-weather-feb/CsWxLI8SQjAcF6Y79ooGpJ/|archive-date=April 12, 2020|archive-url=https://web.archive.org/web/20200412171621/https://www.ajc.com/news/groundhog-meteorologists-predict-weather-feb/CsWxLI8SQjAcF6Y79ooGpJ/|url-status=live}}</ref>

Groundhogs are used in medical research on [[hepatitis B]]-induced [[liver cancer]]. A percentage of the woodchuck population is infected with the woodchuck hepatitis virus (WHV), which is similar to human hepatitis B virus. Humans cannot contract hepatitis from woodchucks with WHV, but the virus and its effects on the liver make the woodchuck the best available animal for the study of viral hepatitis in humans. The only other animal model for hepatitis B virus studies is the chimpanzee, an endangered species.<ref>{{cite news|author=Segelken, Roger|date=February 1, 1966|title=At Cornell, groundhog is harbinger of health|work=CornellChronicle|url=https://news.cornell.edu/stories/1996/02/cornell-groundhog-harbinger-health|access-date=February 20, 2018|archive-date=March 8, 2018|archive-url=https://web.archive.org/web/20180308174058/http://news.cornell.edu/stories/1996/02/cornell-groundhog-harbinger-health|url-status=live}}</ref> Woodchucks are also used in biomedical research investigating [[Metabolism|metabolic function]], [[obesity]], [[Energy homeostasis|energy balance]], the [[endocrine system]], [[reproduction]], [[neurology]], [[cardiovascular disease]], [[cerebrovascular disease]], and [[neoplastic disease]].<ref>{{cite web|url=https://animaldiversity.org/accounts/Marmota_monax/|title=Marmota monax (woodchuck)|website=Animal Diversity Web|access-date=February 20, 2018|archive-date=December 4, 2018|archive-url=https://web.archive.org/web/20181204094939/http://animaldiversity.org/accounts/Marmota_monax/|url-status=live}}</ref> Researching the hibernation patterns of groundhogs may lead to benefits for humans, including lowering of the heart rate in complicated surgical procedures.<ref>Penn State News, (January 29, 2009) "Professor studies groundhog hibernation to benefit mankind"</ref>

Groundhog burrows have revealed at least two [[archaeological site]]s, the [[Ufferman Site]] in the U.S. state of [[Ohio]]<ref name=dohp>Owen, Lorrie K. (ed.) (1999). ''Dictionary of Ohio Historic Places''. Vol. 1. [[St. Clair Shores, Michigan|St. Clair Shores]]: Somerset, p. 328.</ref> and [[Meadowcroft Rockshelter]] in [[Pennsylvania]]. Archaeologists have never [[excavation (archaeology)|excavated]] the Ufferman Site, but the activities of local groundhogs have revealed numerous [[artifact (archaeology)|artifacts]]. They favor the loose soil of the [[esker]] at the site lies, and their burrow digging has brought many objects to the surface: human and animal bones, pottery, and bits of stone.<ref name=dohp/> Woodchuck remains were found in the Indian mounds at [[Aztalan]], Jefferson County, Wisconsin.<ref name="Jackson1961"/>{{rp|124}}

[[Robert Frost]]'s poem "A Drumlin Woodchuck" uses the imagery of a groundhog dug into a small ridge as a [[metaphor]] for his emotional [[reticence]].<ref>{{cite journal| last= Oehlschlaeger| first= Fritz| date= December 1982| title= Two Woodchucks, or Frost and Thoreau on the Art of the Burrow| url= https://digitalcommons.colby.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=3046&context=cq| journal= Colby Quarterly| volume= 18| issue= 4| pages= 214–219| access-date= April 1, 2019| archive-date= January 1, 2020| archive-url= https://web.archive.org/web/20200101022332/https://digitalcommons.colby.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=3046&context=cq| url-status= live}}</ref>

== References ==
{{Reflist|30em}}

==Further reading==
* {{cite book|last1=Bezuidenhout|first1=A. J.|last2=Evans|first2=Howard E.|title=Anatomy of the woodchuck (Marmota monax)|place=Lawrence, KS|publisher=American Society of Mammalogists|year=2005|isbn=978-1-891276-43-9|doi=10.5962/bhl.title.61270|url=https://www.biodiversitylibrary.org/bibliography/61270}}

== External links ==
{{Commons}}
{{Wikispecies|Marmota monax}}
* [https://web.archive.org/web/20130224021837/http://www.hww.ca/en/species/mammals/woodchuck.html Woodchuck], ''[[Hinterland Who's Who]]''
* [https://web.archive.org/web/20120311131559/http://mdc.mo.gov/discover-nature/field-guide/woodchuck-groundhog Woodchuck (Groundhog)], Missouri Conservation Commission
* [https://grants.nih.gov/grants/guide/rfa-files/RFA-NIH-NIAID-DMID-93-010.html NIH Guide: BREEDING AND EXPERIMENTAL FACILITY FOR WOODCHUCKS (MARMOTA MONAX)] Breeding and Experimental Facility for Woodchucks

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[[Category:Groundhogs| ]]
[[Category:Marmots]]
[[Category:Rodents of Canada]]
[[Category:Rodents of the United States]]
[[Category:Fauna of the Eastern United States]]
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[[Category:Mammals described in 1758]]
[[Category:Animal taxa named by Carl Linnaeus]]