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Groundhog | |
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Groundhog at Laval University campus, Quebec, Canada | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Sciuridae |
Genus: | Marmota |
Species: | M. monax |
Binomial name | |
Marmota monax | |
Subspecies | |
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Groundhog range in North America | |
Synonyms | |
Mus monaxLinnaeus, 1758 Contents |
The groundhog (Marmota monax), also known as the woodchuck, is a rodent of the family Sciuridae, belonging to the group of large ground squirrels known as marmots. [2] A lowland creature of North America, it is found through much of the Eastern United States, across Canada and into Alaska. [3] It was first scientifically described by Carl Linnaeus in 1758. [4]
The groundhog plays an important role maintaining healthy soil in woodlands and plains; as such, the species is considered a crucial habitat engineer. [5] [6] [7] The groundhog is an extremely intelligent animal, forming complex social networks and capable of understanding social behavior, forming kinship with its young, understanding and communicating threats through whistling, and working cooperatively to solve tasks such as burrowing. [8] [9]
Common names for the groundhog include chuck, wood-shock, groundpig, whistlepig, [10] [11] whistler, thickwood badger, Canada marmot, monax, moonack, weenusk, red monk, [11] land beaver, [12] and, among French Canadians in eastern Canada, siffleux. [13] The name "thickwood badger" was given in the Northwest to distinguish the animal from the prairie badger. Monax (Móonack) is an Algonquian name of the woodchuck, which means "digger" (cf. Lenape monachgeu). [14] [15] Young groundhogs may be called chucklings. [16] : 66
The etymology of the name woodchuck is unrelated to wood or any sense of chucking. It stems from an Algonquian (possibly Narragansett) name for the animal, wuchak. [17] The similarity between the words has led to the popular tongue-twister: [18]
The groundhog is by far the largest sciurid in its geographical range, except in British Columbia where its range may abut that of its somewhat larger cousin, the hoary marmot. Adults may measure from 41.8 to 68.5 cm (16+7⁄16 to 26+15⁄16 in) in total length, including a tail of 9.5 to 18.7 cm (3+3⁄4 to 7+3⁄8 in). [19] [20] [21] Weights of adult groundhogs typically fall between 2 and 6.3 kg (4 lb 7 oz and 13 lb 14 oz). [21] [22] [23]
Male groundhogs are slightly larger than females on average and, like all marmots, they are considerably heavier during autumn (when engaged in autumn hyperphagia) than when they emerge from hibernation in spring. Adult males average year-around weight 3.83 kg (8 lb 7 oz), with spring to fall average weights of 3.1 to 5.07 kg (6 lb 13 oz to 11 lb 3 oz) while females average 3.53 kg (7 lb 13 oz), with spring to fall averages of 3.08 to 4.8 kg (6 lb 13 oz to 10 lb 9 oz). [19] [24] Seasonal weight changes reflect circannual deposition and use of fat. Groundhogs attain progressively higher weights each year for the first two or three years, after which weight plateaus. [19]
Groundhogs have four incisors, which grow 1.5 millimetres (1⁄16 in) per week. Constant usage wears them down by about that much each week. [25] Unlike the incisors of many other rodents, the incisors of groundhogs are white to ivory-white. [26] [16] : 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 sciurids—only about one-fourth of body length.
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. [27] 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 have summer and winter dens. Human activity has increased food access and abundance, allowing M. monax to thrive. [28]
W.J. Schoonmaker reports that groundhogs may hide when they see, smell, or hear an observer. [16] : 41–43 Marmot researcher Ken Armitage states that the social biology of the groundhog is poorly studied. [29] Despite their heavy-bodied appearance, groundhogs are accomplished swimmers and occasionally climb trees when escaping predators or when they want to survey their surroundings. [30] They prefer to retreat to their burrows when threatened; if the burrow is invaded, the groundhog tenaciously defends itself with its two large incisors and front claws. Groundhogs are generally agonistic and territorial toward conspecifics and may skirmish to establish dominance. [31] [16] : 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". [32] [33] Groundhogs may squeal when fighting, seriously injured, or caught by a predator. [33] Other vocalizations include low barks and a sound produced by grinding their teeth. [33] 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. [34] : 97
Mostly herbivorous, groundhogs eat primarily wild grasses and other vegetation, including berries, bark, leaves, and agricultural crops, when available. [31] [35] In early spring, dandelion and coltsfoot are important groundhog food items. Some additional foods include sheep sorrel, timothy-grass, buttercup, persicaria, agrimony, red and black raspberries, mulberries, buckwheat, plantain, wild lettuce, all varieties of clover, and alfalfa. Groundhogs also occasionally eat small animals, such as grubs, grasshoppers, snails, and even bird eggs and baby birds, but are not as omnivorous as many other Sciuridae. [35] [36]
An adult groundhog can eat more than a pound of vegetation daily. [37] 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. [38] Instead of storing food, groundhogs stuff themselves to survive the winter without eating. [39] Thought not to drink water, groundhogs are reported to obtain needed liquids from the juices of food-plants, aided by their sprinkling with rain or dew. [16] : 85 [40] [41]
Groundhogs are excellent burrowers, using burrows for sleeping, rearing young, and 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 6 cubic feet (0.17 m3) per den. The longest burrow measured 24 feet (7.3 m) plus two short side galleries. [16] : 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. [32] In a June 7 2009 Humane Society of the United States article, "How to Humanely Chuck a Woodchuck Out of Your Yard", 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 ]
The burrow is used for safety, retreat in bad weather, hibernating, sleeping, love nest, 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. [42] The nest chamber may be about twenty inches to three feet (51–91 cm) below ground surface. It is about 16 inches (41 cm) wide and 14 inches (36 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 24 feet (7.3 m), and the average length of eleven dens was 14 feet (4.3 m). [16] : 104–105 W. H. Fisher investigated nine burrows, finding the deepest point 49 inches (120 cm) down. The longest, including side galleries, was 47 ft 11.5 in (14.62 m). [43] Numbers of burrows per individual groundhog decrease with urbanization. [44] [45]
Bachman mentioned that when the 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. [46]
Abandoned groundhog burrows benefit many other species by providing shelter. They are used by cottontail rabbits, raccoons, foxes, river otters, eastern chipmunks, and a wide variety of small mammals, snakes, and birds. [47]
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. [48] Groundhogs hibernate longer in northern latitudes than southern latitudes. [49] [50] To survive the winter, they are at their maximum weight shortly before entering hibernation. [51] When the groundhog enters hibernation, there is a drop in body temperature to as low as 35 degrees Fahrenheit (2 °C), heart rate falls to 4–10 beats per minute and breathing rate falls to one breath every six minutes. [52] During hibernation, they experience periods of torpor and arousal. [53] Hibernating woodchucks lose as much as half their body weight by February. [54] They emerge from hibernation with some remaining body fat to live on until the warmer spring weather produces abundant plant materials for food. [51] Males emerge from hibernation before females. [55] [16] : 50 Groundhogs are mostly diurnal, and are often active early in the morning or late afternoon. [56]
Groundhogs are considered the most solitary of the 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. In Ohio, adult males and females associate with each other throughout the year and often from year to year. [57] [19] Usually groundhogs 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 [28] but only alpine and woodchuck marmot females have been shown to mate with multiple males. [57] A mated pair remains in the same den throughout the 31- to 32-day gestation period. [58] 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. [28] 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. [59] : 316 By the end of August, the family breaks up; or at least, the larger number scatter, to burrow on their own. [60]
In the wild, groundhogs can live up to six years with two or three being average. In captivity, groundhogs reportedly live up to 14 years. Human development, which often produces openings juxtaposed with second growth trees that are incidentally also favored by groundhogs, often ensures that groundhogs in well-developed areas are nearly free of predators other than humans (through various forms of pest control or roadkills) or mid-to-large sized dogs. [61]
Occasionally, woodchucks may suffer from parasitism and a woodchuck may die from infestation or from bacteria transmitted by vectors. [62] 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. [63] : 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 M. monax were taken annually from 1964 to 1971. [64] : 143 Woodchucks had protected status in the state of Wisconsin [65] until 2017. [66] Woodchuck numbers appear to have decreased in Illinois. [67]
Wild predators of adult groundhogs in most of eastern North America include coyotes, badgers, [68] bobcats, 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. [69] [70] [71] [72] [73] [74]
Large predators such as gray wolf and eastern cougar are likely extirpated in the east, but still may hunt groundhogs on occasion in Canada. [75] [76] Golden eagles can also prey on adult groundhogs, but seldom occur in the same range or in the same habitats as this marmot. Likewise, great horned owls can reportedly, per Bent (1938), prey upon groundhogs, but rarely do so, especially given the temporal differences in their behaviors. [77] [78]
Young groundhogs (usually those less than a couple months in age) may also be taken by the American mink, and perhaps other small mustelids, cats, timber rattlesnakes, and hawks. Red-tailed hawks can take groundhogs at least of up to the size of yearling juveniles, and northern goshawks can take them up to perhaps weak emergent-adult groundhogs in the Spring. [19] [21] [79] [80] [81]
Beyond their large size, groundhogs have several successful anti-predator behaviors, usually retreating to the safety of their burrow which most predators will not attempt to enter, but also being ready to defend themselves with their sharp claws and large incisors. They can also scale trees to escape a threat. [64] : 142–143 [82] [ failed verification ] [44] [ failed verification ]
Both their diet and their habit of burrowing make groundhogs serious nuisance animals around farms and gardens. They will eat many commonly grown vegetables. Extensive burrowing can undermine foundations. [32]
Very often, the dens of groundhogs provide homes for other animals, including skunks, red foxes, and cottontail rabbits. Foxes and skunks feed upon field mice, grasshoppers, beetles, 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. [16] : 129–131 In some parts of the U.S., they have been eaten. [83]
A report in 1883 by the New Hampshire Legislative Woodchuck Committee describes the groundhog's objectionable character: [84] [85]
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....
The committee concludes that "a small bounty will prove of incalculable good; at all events, even as an experiment, it is certainly worth trying; therefore your committee would respectfully recommend that the accompanying bill be passed." [16] : 133
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 kill 'em all and let God sort 'em out. You have to work to produce the sweet and cuddly." [86] Groundhogs cared for in wildlife rehabilitation that survive but cannot be returned to the wild may remain with their caregivers and become educational ambassadors. [87] [88] [89]
In the United States and Canada, the yearly February 2 Groundhog Day celebration has given the groundhog recognition and popularity. The most popularly known of these groundhogs are Punxsutawney Phil, Wiarton Willie, Shubenacadie Sam, Jimmy the Groundhog, Dunkirk Dave, and Staten Island Chuck kept as part of Groundhog Day festivities in Punxsutawney, Pennsylvania; Wiarton, Ontario; Sun Prairie, Wisconsin; Dunkirk, New York; and Staten Island respectively. The 1993 comedy film Groundhog Day references several events related to Groundhog Day, and portrays both Punxsutawney Phil himself, and the annual Groundhog Day ceremony. Famous Southern groundhogs include General Beauregard Lee, based at Dauset Trails Nature Center outside Atlanta, Georgia. [90]
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. [91] Woodchucks are also used in biomedical research investigating metabolic function, obesity, energy balance, the endocrine system, reproduction, neurology, cardiovascular disease, cerebrovascular disease, and neoplastic disease. [92] Researching the hibernation patterns of groundhogs may lead to benefits for humans, including lowering of the heart rate in complicated surgical procedures. [93]
Groundhog burrows have revealed at least two archaeological sites, the Ufferman Site in the U.S. state of Ohio [94] and Meadowcroft Rockshelter in Pennsylvania. Archaeologists have never excavated the Ufferman Site, but the activities of local groundhogs have revealed numerous 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. [94] Woodchuck remains were found in the Indian mounds at Aztalan, Jefferson County, Wisconsin. [95]
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. [96]
Marmots are large ground squirrels in the genus Marmota, with 15 species living in Asia, Europe, and North America. These herbivores are active during the summer, when they can often be found in groups, but are not seen during the winter, when they hibernate underground. They are the heaviest members of the squirrel family.
Ground squirrels are rodents of the squirrel family (Sciuridae) that generally live on the ground or in burrows, rather than in trees like the tree squirrels. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks.
The hoary marmot is a species of marmot that inhabits the mountains of northwest North America. Hoary marmots live near the tree line on slopes with grasses and forbs to eat and rocky areas for cover.
The Vancouver Island marmot is a species of marmot endemic to Vancouver Island, in British Columbia. It is one of only five land mammals endemic to Canada.
The American badger is a North American badger similar in appearance to the European badger, although not closely related. It is found in the western, central, and northeastern United States, northern Mexico, and south-central Canada to certain areas of southwestern British Columbia.
The yellow-bellied marmot, also known as the rock chuck, is a large, stout-bodied ground squirrel in the marmot genus. It is one of fourteen species of marmots, and is native to mountainous and semi-arid regions of southwestern Canada and western United States, including the Rocky Mountains, Sierra Nevada, and the Great Basin, often living above 2,000 metres. The fur is mainly brown, with a dark bushy tail, yellow chest and white patch between the eyes, and they weigh up to approximately 5 kilograms. They live in burrows in colonies of up to twenty individuals with a single dominant male. They are diurnal and feed on plant material, insects, and bird eggs. They hibernate for approximately eight months starting in September and lasting through the winter.
The alpine marmot is a large ground-dwelling squirrel, from the genus of marmots. It is found in high numbers in mountainous areas of central and southern Europe, at heights between 800 and 3,200 m (2,600–10,500 ft) in the Alps, Carpathians, Tatras and Northern Apennines. In 1948 they were reintroduced with success in the Pyrenees, where the alpine marmot had disappeared at end of the Pleistocene epoch.
The Olympic marmot is a rodent in the squirrel family, Sciuridae. It occurs only in the U.S. state of Washington, at the middle elevations of the Olympic Peninsula. The closest relatives of this species are the hoary marmot and the Vancouver Island marmot. In 2009, it was declared the official endemic mammal of Washington state.
The Himalayan marmot is a marmot species that inhabits alpine grasslands throughout the Himalayas and on the Tibetan Plateau. It is IUCN Red Listed as Least Concern because of its wide range and possibly large population.
The bobak marmot, also known as the steppe marmot, is a species of marmot that inhabits the steppes of Eastern Europe and Central Asia. It is a social animal and inhabits steppe grassland, including cultivated field borders. It hibernates for more than half the year. Litter sizes average about five offspring and it takes three years for the young marmots to reach sexual maturity. Male offspring leave the home colony after their second winter, and about 60% of mature females give birth in any one year.
The Arctic ground squirrel is a species of ground squirrel native to the Arctic and Subarctic of North America and Asia. People in Alaska, particularly around the Aleutians, refer to them as "parka" squirrels, most likely because their pelt is good for the ruff on parkas and for clothing.
Belding's ground squirrel, also called pot gut, sage rat or picket-pin, is a squirrel that lives on mountains in the western United States. In California, it often is found at 6,500 to 11,800 feet (2,000–3,600 m) in meadows between Lake Tahoe and Kings Canyon. This species is not of conservation concern, and its range includes some protected areas.
The long-tailed marmot or golden marmot is a marmot species in the family Sciuridae. It occurs in mountainous regions in the central parts of Asia where it lives in open or lightly wooded habitats, often among rocks where dwarf junipers grow. It is IUCN Red Listed as Least Concern. As suggested by its name, it is a relatively long-tailed species of marmot.
The gray marmot, grey marmot, or Altai marmot is a species of rodent in the squirrel family Sciuridae. It is one of the larger marmots in the genus Marmota. It occurs in mountainous grasslands and shrub lands of central Asia, and is one of the 9 Palearctic (Eurasia) species. It is found in Xinjiang Province in China, southeastern Kazakhstan, Kyrgyzstan, Mongolia, and in the Altai and Tien Shan Mountains in southeastern Siberia in Russia. In the Mongolian Altai, its range overlaps with that of the Tarbagan marmot. Gray marmots form social groups, live in burrows, and hibernate.
The Alaska marmot, also known as the Brooks Range marmot or the Brower's marmot, is a species of rodent in the family Sciuridae. Once considered to be the same species as the hoary marmot, it is now known to be unique. Alaska marmots are found in the scree slopes of the Brooks Range, Alaska. Specifically, they prefer to dwell on rocky, mountainous terrain, generally near lakes. They eat vegetation found on mountainsides, such as grasses, seeds, and lichen. Their relatively thick bodies are covered in dense, grey fur. They live in large colonies that consist of multiple families. During the winter, they hibernate for long periods of time in burrows. While not well researched, they are not believed to be particularly threatened, by human activity or otherwise. The Alaskan government has designated February 2 as "Marmot Day," a holiday intended to recognize the prevalence of marmots in the state, similar to the more widely celebrated American holiday of Groundhog Day.
The black-capped marmot is a species of rodent in the family Sciuridae. It is endemic to the Russian Far East, but its range is discontinuous and divided into three main parts, each with its own subspecies. The black-capped marmot lives in arctic tundra and alpine habitats from near sea-level to an altitude of 2,000 m (6,600 ft). Depending on exact subpopulation, they hibernate for 6–8 months each year, which is long for a marmot.
The tarbagan marmot is a species of rodent in the family Sciuridae. It is found in China, northern and western Mongolia, and Russia. In the Mongolian Altai Mountains, its range overlaps with that of the Gray marmot. The species was classified as endangered by the IUCN in 2008.
Nesting behavior refers to an instinct in animals during reproduction to prepare a place with optimal conditions for offspring. The nesting place provides protection against predators and competitors that mean to exploit or kill offspring. It also provides protection against the physical environment.
Diandrya is a genus of cestode parasites that are known from marmots in North America. The species Diandrya composita, described along with the genus by J. G. Darrah in 1930, is known from all North American marmots except the woodchuck. The species D. vancouverensis, described by T. F. Mace and C. D. Shepard in 1981, is only known from the Vancouver Island marmot, an island endemic on Vancouver Island. Subsequent research confirmed D. vancouverensis to be genetically unique from D. composita.
The Tatra marmot is an endemic subspecies of marmot found in the Tatra Mountains. In the past, it was a game animal, but in the 19th century, its population drastically declined. It is a herbivore active in the summer, living in territorial family clans in the mountains from the upper montane to the alpine zone. It is one of the rarest vertebrates in Poland and is subject to strict legal protection. It is also legally protected in Slovakia. The Red List of Threatened Animals in Poland and the Polish Red Book of Animals classify the Tatra marmot as a strongly endangered subspecies (EN), while the Red List for the Carpathians in Poland designates it as "CR" – critically endangered. It is a relatively poorly researched animal.