The wolverine (//) (also spelled wolverene), Gulo gulo (Gulo is Latin for "glutton"), also referred to as the glutton, carcajou, skunk bear, or quickhatch, is the largest land-dwelling species of the family Mustelidae. It is a stocky and muscular carnivore, more closely resembling a small bear than other mustelids. A solitary animal, it has a reputation for ferocity and strength out of proportion to its size, with the documented ability to kill prey many times larger than itself.
G. g. luscus
Mustela gulo Linnaeus, 1758
The wolverine is found primarily in remote reaches of the Northern boreal forests and subarctic and alpine tundra of the Northern Hemisphere, with the greatest numbers in Northern Canada, the American state of Alaska, the mainland Nordic countries of Europe, and throughout western Russia and Siberia. Its population has steadily declined since the 19th century owing to trapping, range reduction and habitat fragmentation. The wolverine is now essentially absent from the southern end of its European range.
Within the Gulo gulo species, a clear separation occurs between two subspecies: the Old World form Gulo gulo gulo and the New World form G. g. luscus. Some authors had described as many as four additional North American subspecies, including ones limited to Vancouver Island (G. g. vancouverensis) and the Kenai Peninsula in Alaska (G. g. katschemakensis). However, the most currently accepted taxonomy recognizes either the two continental subspecies or G. gulo as a single Holarctic taxon.
Recently compiled genetic evidence suggests most of North America's wolverines are descended from a single source, likely originating from Beringia during the last glaciation and rapidly expanding thereafter, though considerable uncertainty to this conclusion is due to the difficulty of collecting samples in the extremely depleted southern extent of the range.
Anatomically, the wolverine is a stocky and muscular animal. With short legs, broad and rounded head, small eyes and short rounded ears, it more closely resembles a bear than it does other mustelids. Though its legs are short, its large, five-toed paws with crampon-like claws and plantigrade posture enable them to climb up and over steep cliffs, trees and snow-covered peaks with relative ease.
The adult wolverine is about the size of a medium dog, with a length usually ranging from 65–107 cm (26–42 in), a tail of 17–26 cm (6.7–10.2 in), and a weight of 5.5–25 kg (12–55 lb), though exceptionally large males can weigh up to 32 kg (71 lb). Another outsized specimen was reported to scale approximately 35 kg (77 lb). The males are as much as 30% larger than the females and can be twice the females' weight. According to some sources, Eurasian wolverines are claimed to be larger and heavier than North American with average weights in excess of 20 kg (44 lb) but this may refer more specifically to areas such as Siberia, as data from European wolverines shows they are typically around the same size as their American counterparts. The average weight of female wolverines from a study in the Northwest territories of Canada was 10.1 kg (22 lb) and that of males 15.3 kg (34 lb). In a study from Alaska, the median weight of ten males was 16.7 kg (37 lb) while the average of two females was 9.6 kg (21 lb). In Ontario, the mean weight of males and females was 13.6 kg (30 lb) and 9.9 kg (22 lb). The average weights of wolverines were notably lower in a study from the Yukon territory, averaging 7.3 kg (16 lb) in females and 11.3 kg (25 lb) in males, perhaps because these animals from a "harvest population" had low fat deposits. In Finland, the average weight was claimed as 11 to 12.6 kg (24 to 28 lb). The average weight of male and female wolverines from Norway was listed as 14.6 kg (32 lb) and 10 kg (22 lb). Shoulder height is reported from 30 to 45 cm (12 to 18 in). It is the largest of terrestrial mustelids; only the marine-dwelling sea otter, the giant otter of the Amazon basin and the semi-aquatic African clawless otter are larger, while the European badger may reach a similar body mass, especially in autumn.
Wolverines have thick, dark, oily fur which is highly hydrophobic, making it resistant to frost. This has led to its traditional popularity among hunters and trappers as a lining in jackets and parkas in Arctic conditions. A light-silvery facial mask is distinct in some individuals, and a pale buff stripe runs laterally from the shoulders along the side and crossing the rump just above a 25–35 cm (9.8–13.8 in) bushy tail. Some individuals display prominent white hair patches on their throats or chests.
Like many other mustelids, it has potent anal scent glands used for marking territory and sexual signaling. The pungent odor has given rise to the nicknames "skunk bear" and "nasty cat." Wolverines, like other mustelids, possess a special upper molar in the back of the mouth that is rotated 90 degrees, towards the inside of the mouth. This special characteristic allows wolverines to tear off meat from prey or carrion that has been frozen solid.
Diet and huntingEdit
Wolverines are considered to be primarily scavengers. A majority of the wolverine's sustenance is derived from carrion, on which it depends almost exclusively in winter and early spring. Wolverines may find carrion themselves, feed on it after the predator (often, a pack of wolves) has finished, or simply take it from another predator. Wolverines are also known to follow wolf and lynx trails, purportedly with the intent of scavenging the remains of their kills. Whether eating live prey or carrion, the wolverine's feeding style appears voracious, leading to the nickname of "glutton" (also the basis of the scientific name). However, this feeding style is believed to be an adaptation to food scarcity, especially in winter.
The wolverine is also a powerful and versatile predator. Prey mainly consists of small to medium-sized mammals, but the wolverine has been recorded killing prey such as adult deer that are many times larger than itself. Prey species include porcupines, squirrels, chipmunks, beavers, marmots, moles, gophers, rabbits, voles, mice, rats, shrews, lemmings, caribou, roe deer, white-tailed deer, mule deer, sheep, goats, cattle, bison, moose, and elk. Smaller predators are occasionally preyed on, including martens, mink, foxes, Eurasian lynx, weasels, and coyote and wolf pups. Wolverines have also been known to kill Canadian lynx in the Yukon of Canada. Wolverines often pursue live prey that are relatively easy to obtain, including animals caught in traps, newborn mammals, and deer (including adult moose and elk) when they are weakened by winter or immobilized by heavy snow. Their diets are sometimes supplemented by birds' eggs, birds (especially geese), roots, seeds, insect larvae, and berries.
Wolverines inhabiting the Old World (specifically, Fennoscandia) hunt more actively than their North American relatives. This may be because competing predator populations in Eurasia are not as dense, making it more practical for the wolverine to hunt for itself than to wait for another animal to make a kill and then try to snatch it. They often feed on carrion left by wolves, so changes in wolf populations may affect the population of wolverines. They are also known on occasion to eat plant material.
Wolves are thought to be the wolverine's most important natural predator, with the arrival of wolves to a wolverine's territory presumably leading the latter to abandon the area. Armed with powerful jaws, sharp claws, and a thick hide, wolverines, like most mustelids, are remarkably strong for their size. They may defend kills against larger or more numerous predators such as wolves or bears. By far, their most serious predator is the gray wolf, with an extensive record of wolverine fatalities attributed to wolves in both North America and Eurasia. At least one account reported a wolverine's apparent attempt to steal a kill from a black bear, although the bear won what was ultimately a fatal contest for the wolverine. There are a few accounts of brown bears killing and consuming wolverines as well and, although also reported at times to be chased off prey, in some areas such as Denali National Park, wolverines seemed to try to actively avoid encounters with grizzly bears as they have been reported to in areas where wolves start hunting them. In another account, a wolverine was claimed to have killed an adult polar bear but this account may be dubious.[better source needed]
Mating and reproductionEdit
Successful males will form lifetime relationships with two or three females, which they will visit occasionally, while other males are left without a mate. Mating season is in the summer, but the actual implantation of the embryo (blastocyst) in the uterus is stayed until early winter, delaying the development of the fetus. Females will often not produce young if food is scarce. The gestation period is 30–50 days, and litters of typically two or three young ("kits") are born in the spring. Kits develop rapidly, reaching adult size within the first year. The typical longevity of a wolverine in captivity is around 15 to 17 years, but in the wild the average lifespan is more likely between 8 and 10 years. Fathers make visits to their offspring until they are weaned at 10 weeks of age; also, once the young are about six months old, some reconnect with their fathers and travel together for a time.
Wolverines live primarily in isolated arctic, boreal, and alpine regions of northern Canada, Alaska, Siberia, and Fennoscandia; they are also native to European Russia, the Baltic countries, the Russian Far East, northeast China and Mongolia. In 2008 and 2009, wolverines were sighted as far south as the Sierra Nevada, near Lake Tahoe, for the first time since 1922. According to a U.S. Fish and Wildlife Service publication, as of 2014 "wolverines are found in the North Cascades in Washington and the Northern Rocky Mountains in Idaho, Montana, Oregon (Wallowa Range), and Wyoming. Individual wolverines have also moved into historic range in the Sierra Nevada Mountains of California and the Southern Rocky Mountains of Colorado, but have not established breeding populations in these areas."
In 2004, the first confirmed sighting of a wolverine in Michigan since the early 19th century took place, when a Michigan Department of Natural Resources wildlife biologist photographed a wolverine in Ubly, Michigan. The specimen was found dead at the Minden City State Game Area in Sanilac County, Michigan in 2009; no further wolverines have been spotted in Michigan.
The world's total wolverine population is not known. The animal exhibits a low population density and requires a very large home range. The wolverine is listed by the IUCN as Least Concern because of its "wide distribution, remaining large populations, and the unlikelihood that it is in decline at a rate fast enough to trigger even Near Threatened".
The range of a male wolverine can be more than 620 km2 (240 mi2), encompassing the ranges of several females which have smaller home ranges of roughly 130–260 km2 (50–100 mi2). Adult wolverines try for the most part to keep nonoverlapping ranges with adults of the same sex. Radio tracking suggests an animal can range hundreds of miles in a few months.
Female wolverines burrow into snow in February to create a den, which is used until weaning in mid-May. Areas inhabited nonseasonally by wolverines are thus restricted to zones with late-spring snowmelts. This fact has led to concern that global warming will shrink the ranges of wolverine populations.
This requirement for large territories brings wolverines into conflict with human development, and hunting and trapping further reduce their numbers, causing them to disappear from large parts of their former range; attempts to have them declared an endangered species have met with little success. In February 2013, the United States Fish and Wildlife Service proposed giving Endangered Species Act protections to the wolverine due to its winter habitat in the northern Rockies diminishing. This was as a result of a lawsuit brought by the Center for Biological Diversity and Defenders of Wildlife.
The Wildlife Conservation Society reported in June 2009 that a wolverine researchers had been tracking for almost three months had crossed into northern Colorado. Society officials had tagged the young male wolverine in Wyoming near Grand Teton National Park and it had traveled southward for about 500 miles. It was the first wolverine seen in Colorado since 1919, and its appearance was also confirmed by the Colorado Division of Wildlife. In May 2016 the same wolverine was killed by a cattle ranch-hand in North Dakota, ending a >800 mile trip by this lone male wolverine, dubbed M-56. This was the first verified sighting of a Wolverine in North Dakota in 150 years. In February 2014, a wolverine was seen in Utah, the first confirmed sighting in that state in 30 years.
|Country||Population in surveyed area||Surveyed area||Year||State of population|
|Norway||150+||Snøhetta plateau and North||1995–97||Decline|
|Norway and Sweden - overall||1065||Overall||2012||Increase|
|Finland||155–170||Karelia and North||2008||Stable|
|Finland - overall||165-175||Overall||2012||Increase|
|Russia||1500||European Russia||1970, 1990,||Decline|
|Russia – Komi||885||–||1990||–|
|Russia – Archangelsk Oblast||410||Nenetsky Autonomous Area||1990||Limited|
|Russia – Kola Peninsula||160||Hunting Districts||1990||Decline|
|United States – Alaska||Unknown||Kobuk Valley National Park, Selawik National Wildlife Refuge||1998||Decline|
|United States – Alaska||3.0 (± 0.4 SE) wolverines/1,000 km2||Turnagain Arm and the Kenai Mountains||2004||–|
|United States – Rocky Mountains||28–52||Montana, Idaho, Wyoming||1989–2007||Unknown|
|United States – California||3||Tahoe National Forest||2008||Unknown|
|Canada – Yukon||9.7 (± 0.6 SE) wolverines/1,000 km2||Old Crow Flats||2004||–|
|Canada – Ontario||Unclear||Red Lake – Sioux Lookout to Fort Severn – Peawanuck||2004||Stable to expanding|
|Canada – Overall||15,000–19,000||Overall||–||Stable|
Around a hundred wolverines are held in zoos across North America and Europe, and they have been bred in captivity, but only with difficulty and high infant mortality.
The wolverine's questionable reputation as an insatiable glutton (reflected in the Latin genus name Gulo) may be in part due to a false etymology. The less common name for the animal in Norwegian, fjellfross, meaning "mountain cat", is thought to have worked its way into German as Vielfraß, which means "glutton" (literally "devours much"). Its name in other West Germanic languages is similar (e.g. Dutch: veelvraat).
The Finnish name is ahma, derived from ahmatti, which is translated as "glutton". Similarly, the Estonian name is ahm, with the equivalent meaning to the Finnish name. In Lithuanian is ernis, in Latvian—tinis or āmrija.
The Eastern Slavic росомаха (rosomakha) and the Polish and Czech name rosomák seem to be borrowed from the Finnish rasva-maha (fat belly). Similarly, the Hungarian name is rozsomák or torkosborz which means "gluttonous badger".
In French-speaking parts of Canada, the wolverine is referred to as carcajou, borrowed from the Innu-aimun or Montagnais kuàkuàtsheu. However, in France, the wolverine's name is glouton (glutton).
Purported gluttony is reflected neither in the English name wolverine nor in the names used in North Germanic languages. The English word wolverine (alteration of the earlier form, wolvering, of uncertain origin) probably implies "a little wolf". The name in Proto-Norse, erafaz and Old Norse, jarfr, lives on in the regular Icelandic name jarfi, regular Norwegian name jerv, regular Swedish name järv and regular Danish name jærv.
Many cities, teams, and organizations use the wolverine as a mascot. For example, the US state of Michigan is, by tradition, known as "the Wolverine State", and the University of Michigan takes the animal as their mascot. The association is well and long established: for example, many Detroiters volunteered to fight during the American Civil War and George Armstrong Custer, who led the Michigan Brigade, called them the "Wolverines". The origins of this association are obscure; it may derive from a busy trade in wolverine furs in Sault Ste. Marie in the 18th century or may recall a disparagement intended to compare early settlers in Michigan with the vicious mammal. Wolverines are, however, extremely rare in Michigan. A sighting in February 2004 near Ubly was the first confirmed sighting in Michigan in 200 years. The animal was found dead in 2010.
- Abramov, A.V. (2016). "Gulo gulo". IUCN Red List of Threatened Species. IUCN. 2016: e.T9561A45198537. doi:10.2305/IUCN.UK.2016-1.RLTS.T9561A45198537.en. Retrieved 15 September 2018.
- Koepfli, Klaus-Peter; Deere, KA; Slater, GJ; Begg, C; Begg, K; Grassman, L; Lucherini, M; Veron, G; Wayne, RK (February 2008). "Multigene phylogeny of the Mustelidae: Resolving relationships, tempo and biogeographic history of a mammalian adaptive radiation". BMC Biology. 6: 10. doi:10.1186/1741-7007-6-10. PMC . PMID 18275614. Archived from the original on 3 August 2009.
- Tomasik, Eric & Cook, Joseph A. (2005). "Mitochondrial phylogeography and conservation genetics of wolverine (gulo gulo) of Northwestern North America". Journal of Mammalogy. 86 (2): 386–396. doi:10.1644/BER-121.1.
- Landa, Arild; Lindén, Mats & Kojola, Ilpo (2000). "Action Plan for the conservation of Wolverines (Gulo gulo) in Europe" (PDF). Nature and environment, No. 115. Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention). Archived (PDF) from the original on 29 April 2015. Retrieved 25 January 2008.
- "wolverine (mammal)". Encyclopædia Britannica Online. Archived from the original on 21 January 2010. Retrieved 4 October 2010.
- Burton, Maurice; Burton, Robert (1970). The international wildlife encyclopedia. Marshall Cavendish. pp. 2959–. ISBN 978-0-7614-7266-7. Archived from the original on 31 December 2013. Retrieved 16 September 2011.
- "Gulo gulo – The American Society of Mammalogists" (PDF). smith.edu. Archived from the original (PDF) on 17 June 2012. Retrieved 23 September 2011.
- Zigouris, J.; Schaefer, J. A.; Fortin, C.; Kyle, C. J. (2013). "Phylogeography and post-glacial recolonization in wolverines (Gulo gulo) from across their circumpolar distribution". PLoS ONE. 8 (12): e83837. doi:10.1371/journal.pone.0083837.
- Holbrow, W. C. (1976). The biology, mythology, distribution, and management of the wolverine (Gulo gulo) in western Canada. The University of Manitoba (Masters Thesis).
- Krott, P. (1959). Demon of the North. A.A. Knopf, New York. 260pp. (Translated from German).
- Weedle, F. (1968). The wolverine: the problems of a wilderness outcast. Defenders of Wildlife News 43: 156-168.
- Pond, C. M.; Mattacks, C. A.; Ramsay, M. A. (1994). "The anatomy and chemical composition of adipose tissue in wild wolverines (Gulo gulo) in northern Canada". Journal of Zoology. 232 (4): 603–616. doi:10.1111/j.1469-7998.1994.tb04616.x.
- Ballard, W. B.; Franzmann, A. W.; Gardner, C. L. (1982). "Comparison and assessment of drugs used to immobilize Alaskan gray wolves (Canis lupus) and wolverines (Gulo gulo) from a helicopter". Journal of Wildlife Diseases. 18 (3): 339–342. doi:10.7589/0090-3558-18.3.339.
- Dawson, F. N., Magoun, A. J., Bowman, J., & Ray, J. C. (2010). Wolverine, Gulo gulo, home range size and denning habitat in lowland boreal forest in Ontario. The Canadian Field-Naturalist, 124(2), 139-144.
- Robitaille, J. F., Villano, L., Jung, T. S., Slama, H. P., & Oakley, M. P. (2012). Fat dynamics and development of body condition indices for harvested populations of wolverine Gulo gulo. Wildlife biology, 18(1), 35-45.
- Pulliainen, E. (1968). Breeding biology of the wolverine (Gulo gulo L.) in Finland. In Annales Zoologici Fennici (Vol. 5, No. 4, pp. 338-344). Finnish Zoological and Botanical Publishing Board.
- Järvenpää, J., & Norberg, H. (2011). Carnivore Nature Guide. European Agricultural Fund for Rural Development.
- Wiig, Ø. (1989). Craniometric variation in Norwegian wolverines Gulo gulo L. Zoological Journal of the Linnean Society, 95(3), 177-204.
- Wolverine: Chasing the Phantom. Wolverine Facts Archived 5 November 2014 at the Wayback Machine.. pbs.org
- Pratt, Philip. "Dentition of the Wolverine". The Wolverine Foundation, Inc. Archived from the original on 2008-05-27. Retrieved 2007-07-01.
- Taylor, Ken (1994). "Wolverine". Wildlife Notebook Series. Alaska Department of Fish & Game. Archived from the original on 6 December 2006. Retrieved 21 January 2007.
- Van Dijk, J., Gustavsen, L., Mysterud, A., May, R., Flagstad, Ø., Brøseth, H., ... and Landa, A. (2008). "Diet shift of a facultative scavenger, the wolverine, following recolonization of wolves". Journal of Animal Ecology. 77 (6): 1183–1190. doi:10.1111/j.1365-2656.2008.01445.x.
- Wolverine Gulo gulo Archived 4 June 2012 at the Wayback Machine., eNature.com
- Scrafford, Matthew A., and Mark S. Boyce. "Temporal patterns of wolverine (Gulo gulo luscus) foraging in the boreal forest." Journal of Mammalogy 99, no. 3 (2018): 693-701.
- Gulo gulo (wolverine), Animal Diversity Web
- Heptner, V.G. and Sludskii, A.A. (1992). Mammals of the Soviet Union. Volume II Part 2 Carnivora: Hyenas and Cats. New Delhi: Amerind Publishing, p. 625
- Rockwood, Larry L (2015). Introduction to Population Ecology. Wiley. pp. 273–. ISBN 978-1-118-94755-5. Archived from the original on 5 May 2016.
- World Wildlife Fund–Sweden: 1st International Symposium on Wolverine Research and Management Archived 20 June 2007 at the Wayback Machine. (PDF)
- Glenn Hurowitz (2008-03-05). "First wolverine in 30 years spotted in California Archived 11 August 2012 at the Wayback Machine.", Grist.org; also US Forest Service (6 March 2008). "Camera Spots Wolverine in Sierra Nevada". physorg.com. Archived from the original on 12 October 2008. Retrieved 21 February 2010.
- Rickert, Eve (28 June 2007). "The perils of secrecy". High Country News. Archived from the original on 28 September 2007.
- "Climate change could melt wolverines' snowy refrigerators". Live Science. Archived from the original on 29 July 2015. Retrieved 22 October 2015.
- "World Biomes: Wolverine". Blueplanetbiomes.org. Archived from the original on 23 September 2010. Retrieved 4 October 2010.
- "Wolverine – Montana Fish, Wildlife & Parks". Montana Outdoors. Archived from the original on 28 September 2013.
- Burkholder, B. L. (1962). "Observations concerning wolverine". Journal of Mammalogy. 43 (2): 263–264. doi:10.2307/1377101.
- Boles, B. K. (1977). Predation by wolves on wolverines. Canadian Field-Naturalist, 91(1), 68-69.
- Palomares, F.; Caro, T. M. (1999). "Interspecific killing among mammalian carnivores" (PDF). The American Naturalist. 153 (5): 492–508. doi:10.1086/303189.
- White, K. S., Golden, H. N., Hundertmark, K. J., & Lee, G. R. (2002). Predation by Wolves, Canis lupus, on Wolverines, Gulo gulo, and an American Marten, Martes americana, in Alaska. Canadian Field-Naturalist, 116(1), 132-134.
- "When Predators Attack (Each Other): Researchers Document First-known Killing of a Wolverine by a Black Bear In Yellowstone" (Press release). Science Daily. 6 May 2003. Archived from the original on 20 February 2007. Retrieved 16 January 2007.
- Krebs, John; Lofroth, Eric; Copeland, Jeffrey; Banci, Vivian; Cooley, Dorothy; Golden, Howard; Magoun, Audrey; Mulders, Robert; Shults, Brad (2004). "Synthesis of Survival Rates and Causes of Mortality in North American Wolverines". Journal of Wildlife Management. 68 (3): 493. doi:10.2193/0022-541X(2004)068[0493:SOSRAC]2.0.CO;2. JSTOR 3803381.
- Murie, A. (2012). The grizzlies of Mount McKinley. University of Washington Press.
- Allardyce, Mark (2000). Wolverine – A Look Into the Devils Eyes. pp. 20, 165. ISBN 978-1-905361-00-7.
- Phelps, Gilbert (1989). Between man and beast: true tales & observations of the animal kingdom. Random House Value Publishing. p. 73. ISBN 0-517-69038-1.
- Raloff, Janet (21 October 2010). "Wolverine: Climate warming threatens comeback". Science News. Society for Science & the Public. 178. Archived from the original on 13 May 2013. Retrieved 31 October 2010.
- Wild Mammals of North America: Biology, Management, and Conservation Archived 15 May 2016 at the Wayback Machine. By George A. Feldhamer, Bruce C. Thompson, Joseph A. Chapman -- The Johns Hopkins University Press 2003 page 676
- Knudson, Tom (5 April 2008). "Sighting prompts California to expand search for elusive wolverine". Sacramento Bee. Archived from the original on 18 July 2008.
- Griffith, Martin (22 March 2009). "A year later, wolverine spotted again in Sierra". San Francisco Chronicle. Archived from the original on 26 April 2009.
- Wolverine Sighting on SPI Land near Truckee Archived 6 February 2011 at the Wayback Machine.. yubanet.com. 18 March 2009
- "Archived copy". Archived from the original on 13 September 2017. Retrieved 12 July 2017.
- Wolverine, U.S. Fish and Wildlife Service Mountain-Prairie Region (last updated August 25, 2014).
- Runk, David. First Michigan wolverine spotted in 200 years, Associated Press (February 25, 2004).
- Kyle Mattson, Michigan's first wolverine in 200 years was not just spotted, MLive (January 18, 2016).
- "Archived copy". Archived from the original on 23 March 2014. Retrieved 26 February 2014.
- U.S. Proposes to Protect Wolverines Archived 4 September 2017 at the Wayback Machine. February 1, 2013 New York Times
- Judge: Climate change imperils wolverines April 6, 2016
- "Wolverine confirmed in Colo., the first since 1919". Atlanta Journal Constitution. Associated Press. 19 June 2009. Archived from the original on 27 February 2014.
- Levin, Sam (13 May 2016). "'Killed this here critter': outrage after US rancher shoots rare wolverine". Archived from the original on 10 June 2016.
- Crofts, Natalie (2 July 2014). "Wolverine caught on camera in Utah for 1st time". ksl.com. Archived from the original on 14 July 2014.
- "Conservation status of large carnivores". Environment > Nature and Biodiversity. European Commission. 10 May 2016. Archived from the original on 13 January 2017. Retrieved 12 December 2016.
- Shults, Brad; Peltola, Gene; Belant, Jerrold & Kunkel, Kyran (1998). "population ecology of wolverines within Kobuk valley national park and Selawik national wildlife refuge". Rocky Mountain Research Station, US Department of Agriculture – Forest Service. Archived from the original on 2010-12-18. Retrieved 2008-01-26.
- Goldena, Howard N.; Henryb, J. David; Beckera, Earl F.; Goldsteinc, Michael I.; Mortond, John M.; Frost, Dennis & Poef, Aaron J. (2007). "Estimating wolverine Gulo gulo population size using quadrat sampling of tracks in snow". Alaska Department of Fish and Game, Division of Wildlife Conservation; Parks Canada – Kluane National Park; US Forest Service – Alaska Regional Office; United States Fish and Wildlife Service, Kenai National Wildlife Refuge; North Yukon Renewable Resources Council; United States Forest Service, Chugach National Forest;. 13: 52. doi:10.2981/0909-6396(2007)13[52:EWGGPS]2.0.CO;2.
- Schwartz, Michael K.; Copeland, Jeffrey P.; Anderson, Neil J.; Squires, John R.; Inman, Robert M.; McKelvey, Kevin S.; Pilgrim, Kristy L.; Waits, Lisette P. & Cushman, Samuel A. (2010). "Wolverine gene flow across a narrow climatic niche" (PDF). Ecology 90:3222–3232. Ecological Society of America. Archived (PDF) from the original on 29 June 2011. Retrieved 14 October 2010.
- "Wolverines in California – California Department of Fish and Game". Dfg.ca.gov. Archived from the original on 2015-01-18. Retrieved 2012-09-15.
- Magoun, Audrey; Dawson, Neil; Lipsett-Moore, Geoff; Ray, Justina C. (2004). "Boreal Wolverine: A Focal Species for Land Use planning in Ontario's Northern Boreal Forest – Project Report" (PDF). The Wolverine Foundation, Inc., Ontario Ministry of Natural Resources, Ontario Parks, Wildlife Conservation Society (WCS)/University of Toronto. Archived from the original (PDF) on 2010-11-04. Retrieved 2008-01-26.
- Slough, Brian; et al. (May 2003). "COSEWIC Assessment and Update Status Report on the Wolverine (Gulo gulo) – Eastern Population Western Population in Canada" (PDF). COSEWIC (committee on the status of endangered wildlife in Canada) 2003. COSEWIC assessment and update status report on the wolverine Gulo gulo in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 41 pp. Retrieved 2008-01-26.
- "Gulo gulo – Wolverine". International Species Identification System. May 2010. Retrieved 2010-05-09.
- Duden Archived 9 November 2014 at the Wayback Machine. (in German)
- "The Free Dictionary". The Free Dictionary. Retrieved 2010-10-04.
- Runk, David (25 February 2004). "First Michigan wolverine spotted in 200 years". Associated Press. Archived from the original on 6 December 2008. Retrieved 23 December 2008.
- Bell, Dawson (15 March 2010). "Only known wolverine in the Michigan wild dies". Detroit Free Press. Archived from the original on 6 July 2015.
- Armitage, Peter (1992). "Religious ideology among the Innu of eastern Quebec and Labrador" (PDF). Religiologiques. 6. Archived from the original (PDF) on 1 January 2007. Retrieved 2007-06-29. (PDF)
|Wikispecies has information related to Gulo gulo|
|Wikimedia Commons has media related to Gulo gulo.|