Alaska marmot
Alaska marmot | |
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Scientific classification | |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Rodentia |
Family: | Sciuridae |
Genus: | Marmota |
Species: | M. broweri
|
Binomial name | |
Marmota broweri Hall & Gilmore, 1934
| |
Range of Marmota broweri in Alaska. Its range also extends slightly into Canada. |
The Alaska marmot (Marmota broweri), also known as the Brooks Range marmot[2] or the Brower's marmot,[3] is a species of rodent in the family Sciuridae. It is found in the scree slopes of the Brooks Range, Alaska. They eat grass, flowering plants, berries, roots, moss, and lichen.[4] These marmots range from about 54 centimetres (21 in) to 65 centimetres (26 in) in length and 2.5 kilograms (5.5 lb) to 4 kilograms (8.8 lb) in weight.[5] Alaska celebrates every February 2 as "Marmot Day," a holiday intended to observe the prevalence of marmots in that state and take the place of Groundhog Day.[6]
Etymology[]
Originally Marmota broweri was perceived as a synonym for M. caligata,[7][8] but this was soon proven false when evidence was found that corroborated M. broweri as a unique species.[9][10][11] Cytochrome b sequences were used to verify that M. broweri as its own distinct species.[11]
History[]
Marmota broweri are sometimes hunted by Alaskan Natives for food and their warm fur.[12] An Eskimo hunter would spend all summer hunting marmots to make a parka, as it takes about 20 marmot pelts to make a single parka.[12]
Marmot Day is essentially Alaska's version of Groundhog Day.[13] Sarah Palin signed a bill in 2009 to officially make every February 2 Marmot Day.[13] The bill, introduced by Senator Linda Menard, said, "It made sense for the marmot to become Alaska's version of Punxsutawney Phil, the Pennsylvania groundhog famed for his winter weather forecasts."[13] She did not expect marmots to have any weather forecasting duties but rather hoped that the state would create educational activities regarding the marmot.[13]
Status[]
The status of Alaska marmots is not well known due to the difficulties in finding them in their natural habitats.[5] According to IUCN, the Alaska marmot is considered to be of "least concern" status, signifying relatively low concern in terms of the dangers they face.[12] Although Alaska marmots may be hunted, their population is stable and not at risk for endangerment.[12] In fact, the Alaska marmot has been declared the least threatened species of marmot.[3]
Description[]
General[]
Alaskan marmots are mammals.[12] They possess a short neck, broad and short head, bushy tail, small ears, short powerful legs and feet, densely furred tail, and a thick body covered in coarse hair.[4] Adult Alaska marmots’ fur on their nose and the dorsal part of their head are usually of a dark color.[12] Their feet may be light or dark in color.[4] M. broweri have tough claws adapted for digging,[4] however the thumbs of their front limbs do not have these claws but flat nails instead.[12] Their body size is highly variable due to hibernation cycles.[14] For males, the average total length is 61 centimetres (24 in) and the average weight is 3.6 kilograms (7.9 lb).[2] Adult females are slightly smaller, having an average length of 58 centimetres (23 in) and 3.2 kilograms (7.1 lb).[2]
Anatomical distinctions[]
The retina of the eye of Alaska marmots is entirely lacking of rods, making their night vision quite poor.[3] They also lack the fovea of the eye, making their visual acuity much worse than other rodents.[3] The location of their eyes makes their field of vision very wide, sideways and upward.[3] All of their teeth will grow throughout their lifetime, resembling sharp rodent incisors.[12][failed verification] There is a single pair of incisors in each jaw.[3]
Ecology[]
Location and distribution[]
In terms of global distribution, the Alaska marmot is nearctic.[5] Current distribution of the Alaska marmot include the Brooks Range, Ray Mountains, and Kokrines Hills.[15] They exist in the mountains that lie north of the Yukon and Porcupine rivers in central and northern Alaska.[5] However, there have been reports of Alaska marmots in the Richardson Mountains in the northern Yukon Territory but these sightings have not yet been confirmed.[5][16]
Alaska marmots are found scattered throughout Alaska as small colonies each consisting of various families.[17] Their locations have been documented in the Brooks Range from Lake Peters to Cape Lisburne and Cape Sabine that lies westward.[18] There have been sightings of marmots near rivers in the Northern Baird mountains and in the Mulik Hills.[19] They have also been sighted near copter Peak in the DeLong Mountains.[20] Species have also been secured south of the Brooks Range in the Spooky Valley and in the Kokrines Hills.[5]
Habitat[]
The Alaska marmots live in polar habitats including the terrestrial tundra and mountain biomes.[12] They are located at elevations of about 1,000 metres (3,300 ft) to 1,250 metres (4,100 ft).[12] They are often found in boulder fields, rock slides and outcrops, terminal moraines, and Talus slopes[4] in Alpine tundra with herbaceous forage.[5] They are often found on mountain slopes surrounding lakes, and are found less commonly away from a lake.[21] To create their shelter Alaska marmots burrow into permafrost soil containing tundra vegetation, and within ten meters a rocky ledge serves as an observation post.[12] Alaska marmots live in relatively permanent winter dens that serve as a marmot colonies’ shelter for at least twenty years.[3] A colony is essentially several individual family burrows built in close proximity to one another.[4] Their dark fur serves as a mild camouflage in their rocky environments.[12] Wind is also very important to an Alaska marmot's habitat and climate because it removes annoying mosquitoes.[4] If there are large amounts of mosquitoes in the area due to a lack of wind, marmots will actually remain in their dens until the climate changes and the number of mosquitoes decrease.[12]
Diet[]
Tundra vegetation that grows on mountain sides are the primary nutrition source and they include; grasses, forbs, fruits, grains, legumes, and occasionally insects.[2][3] M. bromeri must eat large amounts of the arctic plants because they are low in nutritional value and for preparation of hibernation.[2] Alaska marmots are typically known as omnivores but they have also been described as insectivorous, folivorous, frugivorous, and granivorous.[3]
Predation[]
Common Alaska marmot predators include; wolverines, gray wolves, grizzly bears, coyotes, foxes and eagles (the main predator for young marmots).[4]
Dangers[]
Although dangers of direct human disturbance are minimal, climate dangers pose a real problem.[3] The Alaska marmot is arguably the most sensitive of the 14 marmot species to anthropogenic disturbances, including climate change.[3]
Ecosystem impact[]
Marmots enrich soil with uneaten food, nesting material, and their feces, and help to aerate the soil with their excessive digging.[4] They also serve as a minor food source for a variety of predators.[12]
Behavior[]
Social behavior[]
Alaska marmots are very social, living in colonies of up to 50 while all sharing a common burrow system.[3] Marmots typically have their own personal den, while the young live with their mother and the father lives in a nearby den.[12] Especially in large colonies, the Alaska marmots utilize sentry duty rolls that are periodically rotated. A sentry marmot will alert the colony via a two-toned, high-pitched warning call (marmot vocalizations) if there is a predator in the area.[4] The older marmots will defend and keep a lookout for predators while the young play.[12] Solely dirt dug dens provides limited protection, but a den built under rocks and boulders can prevent the risk from large animals, such as grizzly bears, who can dig marmots out of their dirt dug dens.[12]
M. broweri will mark their territory by secreting a substance from face-glands and rubbing the sides of their face on rocks around their den and various trails.[11] Alaska marmots also enjoy sunbathing and spending a large amount of time in personal grooming.[3]
Hibernation[]
M. broweri is one of the longer hibernating marmots, being documented to do so up to eight months annually.[3] Alaska marmots accumulate a thick fat layer by late summer to sustain them throughout the winter hibernation.[4] Alaska marmots are active until snow begins to fall, in which they will go to their hibernacula from around September until June.[2] Alaska marmots have special winter dens with a single entrance that is plugged with a mixture of dirt, vegetation, and feces during the entire winter hibernation period.[4] They are built on exposed ridges that thaw earlier than other areas, and the entire colony stays within the den from September until the plug melts in early May.[4] They then resettle in their dens in family units to communally hibernate for the winter.[14] Communal hibernation may be an adapted strategy to reduce metabolic cost while trying to keep their body temperatures above freezing.[14] In order to seal their hibernaculum off from the elements, they will plug their entrance with hay, earth, and stone.[12] During hibernation many of their body functions decrease; body temperature (averages between 4.5 °C (40.1 °F) and 7.5 °C (45.5 °F)), heart rates, respiratory rates,[12][14] and metabolic rates. Alaska marmot hibernation is not continuous because they will awaken every three or four weeks in order to urinate and defecate.[3][14] Inside the hibernaculum den, the Alaska marmot has shown long-term hibernation adaptions by their ability to tolerate high CO2 levels and low O2 levels.[22] As an adaption to the Arctic environment and permanently frozen ground, Alaska marmots breed prior to emerging from the winter den.[4] The Alaska marmots will generally emerge from the den during the first 2 weeks of May.
Reproductive[]
Male Alaska marmots are polygynous, mating with the monogamous females living on their territory.[12] They are seasonal iteroparous and viviparous breeders that mate once per in the early spring and give birth about six week later with litter sizes ranging from 3 to 8 and an average litter size of 4–5.[12] The male and female Alaska marmots are involved in both raising and protecting the pups in their natal burrow.[12] In both sexes sexual reproductive behaviors are stimulated by odors released from anal scent glands.[12] Before birthing, the female will first close her den off and then she will give birth alone.[12] The Gestation period is about 5–6 weeks.[12] Newly born Alaskan marmots are altricial;[12] hairless, toothless, blind[4] and are quite vulnerable to predators. After about six weeks young marmots have thick, soft fur and they begin to temporarily leave the den.[12] They will go through 3 coats in their first year until their final one, which resembles adult Alaska marmots.[12] They will hibernate and live with their parents at least one year, they will be fully-grown after two years and reach sexual maturity from 2 to 3 years.[4][12] Marmots life span are not known but it is believed to be about 13–15 years.[12]
Captive rearing[]
M. broweri has been reported to have been successfully reared in captivity and reintroduced into the wild (however there have been cases where captive rearing led to high rates of mortality).[3]
Evolution and fossils[]
The Alaska marmot has ancestry to the Pleistocene epoch.[11] There have been no known fossils of Marmota broweri.[5] However, the M. flavescens fossil recovered from the Late Pleistocene age from the Trail creeks caves on the Seward Peninsula[23] is speculated to be an incorrect identification of the fossil[5] This fossil could be M. broweri.[5]
The evolutionary lineages of the 14 marmot species distributed across the Holarctic are relatively ambiguous.[24] Cytochrome b sequences indicated that M. broweri is most likely related to M. caudata, cenzbieri, marmota, and monax.[24] In support to the cytochrome b results, experimentation involving mitochondrial DNA has suggested that M. broweri is most likely related to M. caudata and M. menzbieri.[3] However, morphological data have linked M. broweri to M. camtschatica.[3] In addition, somatic chromosome analysis of marmots, ecological data and behavioral data have shown that there is a link between M. broweri and M. caligata.[25] The conflicting data pertaining to phylogeny creates inconsistent marmot lineage relationship hypotheses.
References[]
- ^ Linzey, A. V.; Hammerson, G.; Cannings, S. (2008). "Marmota broweri". IUCN Red List of Threatened Species. 2008. Retrieved 6 January 2009.
- ^ Jump up to: a b c d e f "North American Mammals: Marmota Broweri". Smithsonian Institution National Museum of Natural History. Retrieved 7 October 2011.
- ^ Jump up to: a b c d e f g h i j k l m n o p q r Hubbart, Jason A. (2011). "CURRENT Understanding of the Alaska marmot (Marmota Broweri): A Sensitive Species in a Changing Environment". J Biol Life Sci: 6–13. Archived from the original on 2012-04-26. Retrieved 28 November 2011.
- ^ Jump up to: a b c d e f g h i j k l m n o p Curby, Catherine. "Marmot.Wildlife Notebook Series(On-line)" (PDF). Alaskan Department of Fish & Game. Retrieved 2 December 2011.
- ^ Jump up to: a b c d e f g h i j MacDonald, S. O. (2009). Recent Mammals of Alaska. Fairbanks, AK: University of Alaska. pp. 65–66.
- ^ The Associated Press. "Alaska to celebrate its first Marmot Day," Archived 2010-02-05 at the Wayback Machine Fairbanks Daily News-Miner. Feb. 1, 2010. Accessed Feb. 1, 2010.
- ^ Hall, E.R.; R.M. Gilmore (1934). "Marmota caligata broweri, a new marmot from northern Alaska". Canadian Field-Naturalist. 48: 57–59.
- ^ Hall, E.R. (1981). The mammals of North America. New York: Wiley-Inter science.
- ^ Rausch, R. L.; V. R. Rausch (1965). "Cytogenic evidence for the specific distinction of an Alaskan marmot, Marmota broweri Hall and Gilmore (Mammalia: Sciuridae)". Chromosoma (Berlin). 16 (5): 618–623. doi:10.1007/bf00326977. PMID 5857562. S2CID 22442599.
- ^ Hoffmann, R. S.; J.W. Koeppl; C.F. Nadler (1979). "The relationships of the amphiberingian marmots (Mammalia: Sciuridae)". University of Kansas Museum of Natural History, Occasional Paper. 83: 1–56.
- ^ Jump up to: a b c d Rausch, R. L.; V.R. Rausch (March 1971). "The somatic chromosomes of some North American marmots (Sciuridae), with remarks on the relationships of Marmota broweri Hall and Gilmore". Mammalia. 35: 85–101. doi:10.1515/mamm.1971.35.1.85. S2CID 85371571. Retrieved 25 November 2011.
- ^ Jump up to: a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad Rasmussen, J. "Marmota Broweri (On-line)". Animal Diversity Web. Retrieved 25 November 2011.
- ^ Jump up to: a b c d "Marmot Day: Alaska Adopts Its Own Version Of Groundhog Day". Green News: The Huffington Post. 1 February 2010. Retrieved 27 November 2011.
- ^ Jump up to: a b c d e Lee, T. N.; B. M. Barnes; C. L. Buck (2009). "Body Temperature Patterns during Hibernation in a Free-living Alaska marmot (Marmota Broweri)". Ethology Ecology & Evolution. 21 (3–4): 403–13. doi:10.1080/08927014.2009.9522495. S2CID 85045056.
- ^ Gunderson, Aren M.; Brandy K. Jacobsen; Link E. Olson (2009). "Revised Distribution of the Alaska Marmot, Marmota broweri, and Confirmation of Parapatry with Hoary Marmots". Journal of Mammalogy. 90 (4): 859–869. doi:10.1644/08-mamm-a-253.1. S2CID 51772006.
- ^ Youngman, P. M. (1975). "Mammals of the Yukon Territory". National Museums of Canada, Ottawa, Publications in Zoology. 10: 1–192.
- ^ Hoffmann, R. S. (1999). D. E. Wilson; S. Ruff (eds.). "Alaska Marmot, Marmota broweri". The Smithsonian Book of North American Mammals: 393–395.
- ^ Childs, H. E. (1969). "Birds and mammals of the Pitmegea River region". Cape Sabine, Northwestern Alaska, Biological Papers of the University of Alaska: No. 10.
- ^ Dean, F. C.; D. L. Chesemore (1974). "Studies of birds and mammals in the Baird and Schwatka mountains". Alaska. Biological Papers of the University of Alaska: No. 15.
- ^ Macdonald, S. O.; J. A. Cook (2002). "Mammal inventory of Alaska's National Parks and Preserves". Northwest Network: Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Kobuk Valley National Park, Noatak National Preserve, National Park Service Alaska Region, Inventory and Monitoring Program Annual Report 2001.
- ^ Bee, J. W.; E.R. Hall (1956). Mammals of northern Alaska on the Arctic slope. 8. University of Kansas Museum of Natural History: Miscellaneous Publication. pp. 1–309. Archived from the original on 2013-12-13. Retrieved 2011-11-25.
- ^ Williams, D.; R. Rausch (1973). "Seasonal Carbon Dioxide and Oxygen Concentrations in the Dens of Hibernating Mammals (Sciuridae)". Comparative Biochemistry and Physiology A. 44 (4): 1227–235. doi:10.1016/0300-9629(73)90261-2. PMID 4145522.
- ^ Yesner, D.R. (2001). "Human dispersal into interior Alaska: Antecedent conditions, mode of colonization, and adaptions". Quaternary Science Reviews. 20 (1–3): 315–327. Bibcode:2001QSRv...20..315Y. doi:10.1016/S0277-3791(00)00114-1.
- ^ Jump up to: a b Steppan, Scott; et al. (1999). "Molecular Phylogeny of the Marmots (Rodentia: Sciuridae): Tests of Evolutionary and Biogeographic Hypotheses". Systematic Biology. 48 (4): 715–734. doi:10.1080/106351599259988. PMID 12066297. Retrieved 28 November 2011.
- ^ Rausch, Robert; Virginia Rausch (1971). "The Somatic Chromosomes of Some North American Marmots (Sciuridae), with Remarks on the Relationships of Marmota Broweri Hall and Gilmore". Mammalia. 35 (1): 85–101. doi:10.1515/mamm.1971.35.1.85. S2CID 85371571.
External links[]
Media related to Marmota broweri at Wikimedia Commons
- IUCN Red List least concern species
- Marmots
- Mammals of the United States
- Arctic land animals
- Mammals described in 1934