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For information on Wisconsin's rare vertebrate animals, contact:
Rich Staffen
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Conservation Biologist

American Marten (Martes americana)



American Marten (Martes americana), a State Endangered mammal, lives in mature, dense conifer forests, mixed conifer-hardwood, and hardwood dominanted forests. American martens prefer forests with a mixture of conifers and deciduous trees including hemlock, white pine, yellow birch, maple, fir and spruce. Marten young are born in tree dens in late March and April and are weaned when about 6 weeks old. To avoid potential take of dependent kits in suitable habitat, within American marten range, do not cut trees between March 15 and May 31.

State status

Status and Natural Heritage Inventory documented occurrences in Wisconsin

The table below provides information about the protected status - both state and federal - and the rank (S and G Ranks) for American Marten (Martes americana). See the Working List Key for more information about abbreviations. Counties shaded blue have documented occurrences for this species in the Wisconsin Natural Heritage Inventory database. The map is provided as a general reference of where occurrences of this species meet NHI data standards and is not meant as a comprehensive map of all observations.

Note: Species recently added to the NHI Working List may temporarily have blank occurrence maps.

Documented locations of Martes americana in the Natural Heritage Inventory Database as of July 2015.
Summary Information
State StatusEND
Federal Status in Wisconsinnone
State RankS2
Global RankG5
Tracked by NHIY

Species guidance

Identification: American martens are small, rare members of the weasel family. The American marten is sometimes referred to as pine marten due to the similarities shared with their European pine marten relatives. Their fur is soft and thick, varying in color from pale buff or yellow to reddish or dark brown. The animals' throats are pale buff to orange; their tails and legs are dark brown. Two vertical black lines run above the inner corners of their eyes. In winter, long hairs grow between the toe pads on the American martens' feet. These keep the feet warm and enable the animals to travel on deep, soft snow.

American martens have long, bushy tails that are one-third of their total length. Like other species in the weasel family, they differ in size according to sex. The female is about two-thirds the size of the male.

Sometimes people confuse American martens with two other members of the weasel family that live in Wisconsin, fishers (Martes pennanti) and stone martens (Martes foina). Fishers live in similar habitat and have similar tracks. However, they're larger (females 20-27 inches, 4-8 pounds; males 30- 40 inches, 7-15 pounds) and darker than American martens. Also, proportionately larger ears and the reddish-yellow throat patch characteristic of American Martens help distinguish the two species. Stone martens are a species native to Europe and Asia. They escaped into southern Wisconsin in the early 1960s or 1970s, where they've established a small breeding population. Stone martens are 23-31 inches long (including the tail), weigh 1-4.5 pounds and are pale gray to brown with a white throat patch.

Habitat: American martens live in mature, dense conifer, deciduous, and mixed conifer-hardwood forests. They prefer forests with a mixture of conifers and deciduous trees including cedar, balsam, hemlock, white pine, yellow birch, maple, fir and spruce. Especially critical to marten use is the presence of large snags, fallen trees, stumps and root mounds, known as coarse woody debris. These forests provide prey, protection and den sites. Mature trees with large cavities are also important, meaning yellow birch may be an important species. Areas with windfalls provide the needed shelter, prey abundance, and access to the prey at ground surface under deep snow. Optimal winter habitat is characterized as mature to overmature conifer forest with 40% fir or spruce and canopy closure greater than 50%. Martens rarely cross open areas. Historically, cutting of large areas of mature conifer forests destroyed much marten habitat.

State Distribution: In Wisconsin, the marten is found in portions of Douglas, Bayfield, Ashland, Sawyer, Iron, Price, Vilas, Oneida, Florence and Forest counties. In 1972, American martens were placed on the Wisconsin Endangered Species List. The most recent estimate for the Nicolet population, completed in 2005, reported 221 + 61 animals. No estimate is available for the Chequamegon population. It appears that Wisconsin marten populations on the Nicolet landbase are stable at this time, however the Chequamegon population likely is declining in at least a portion of their range. Through recent surveys, DNR and our partners have documented small marten populations in Iron and Douglas Counties. It is suspected that these populations have been present for many years and were established by dispersing marten from our neighboring states of Minnesota and Michigan.

Global Distribution: Historically, American martens inhabited mature conifer forests of the northern United States north to tree line in Canada. Populations extended southward along the Sierra Nevada Mountains in California, the Rocky Mountains to New Mexico, the Great Lakes and the Ohio River Valley to northern Ohio. Today, American martens live across Canada and Alaska and in the Sierra Nevada Mountains, the Rocky Mountains south to Colorado and the northern parts of Minnesota, Wisconsin, Michigan, and the East coast states of Maine, New York and New Hampshire. As a species, American martens are not endangered in the U.S. or Canada. In some parts of their range, however, martens have been extirpated or are endangered.

Rationale for Species Listing and Threats: The mature conifer forests that covered northern Wisconsin before the 1800s provided prime habitat for American martens, which lived throughout the northern part of the state. With the arrival of European settlers, trappers and lumbermen who cut forests and trapped martens without any regulations, marten populations declined. Trapping was banned in 1921, but by 1940 martens had been extirpated from the state (reintroductions would later occur).

Diet: American martens are mostly carnivorous, but at certain times of the year feed extensively on wild fruits. Even though they're at home in trees, they do most of their hunting on the ground. They have a high metabolism, thus require a lot of food for energy. This intense need for food makes them easy to trap. Mice and other small rodents are martens' primary prey, but they also eat squirrels, hares, shrews, birds, bird eggs, amphibians, reptiles, insects, fish, crayfish, nuts, fruits and carrion. In winter, martens will tunnel under the snow in search of mice and other small mammals.

Life and Natural History: Little is known about the habits of American martens since they can be active at night, den during the day and are usually are very shy. Unlike most members of the weasel family, American martens (and fishers) are excellent climbers. They pursue prey, such as red squirrels or chipmunks, up a tree and can climb trees to avoid danger. Martens move across the forest floor in a zig-zag fashion, often followed by a series of jumps. They're solitary but curious animals.

In Wisconsin, male marten territories average about 2 square miles, while female's average about 1.0 square mile. Martens generally cover their entire territory every 8-10 days as they hunt. Martens are highly territorial and neither males nor females will tolerate another American marten of the same sex in their territory.

American martens first mate when they're about two years old. During the July-August breeding season, martens (especially males) become quite aggressive and will fight with other mature males. Courtship consists of playing and wrestling, followed by mating. Both males and females may mate with several partners during the breeding season.

Although the female marten's eggs are fertilized by mid-summer, they don't fasten to the wall of her uterus until January or February. The fetuses then develop quickly; young are born in late March or April, nine months after fertilization. The female makes a den in a hollow tree, stump or rock crevice, lines it with leaves, moss and other vegetation and gives birth to 2- 4 kits. The male takes no part in rearing the young.

The sparsely furred, newborn American martens are born with their eyes closed. When the kits are five weeks old the female begins to feed them meat. They are weaned at 6-7 weeks and almost full-grown when three months old. The female leaves her kits soon after they're weaned, when she's able to mate again. Young martens normally disperse out of their home territory in late summer or early fall to establish their own territories.

Management Guidelines: Efforts to reestablish American martens in Wisconsin began in 1953, when the Wisconsin Conservation Department imported five animals from Montana and released them on Stockton Island in Ashland County. There were no known survivors from this group.

In 1956, dry-land trapping was banned in two areas (combined total of 532 square miles) within the Chequamegon-Nicolet National Forest to protect reintroduced fishers. Later, martens, too, were reintroduced into the protected areas. Currently, these sites are referred to as Marten Restoration Areas and are still closed to upland trapping.

Between 1975 and 1983, the DNR Bureau of Wildlife Management and the U.S. Forest Service obtained 172 American martens from Ontario and Colorado and released them in the Nicolet National Forest in northeastern Wisconsin.

During a 1985 study to evaluate the American marten population in the Nicolet National Forest, researchers live-trapped 17 marten. The population was estimated to be 100-150 marten, but was still centered within the release sites in Marten Restoration Area

From 1987 to 1990, Wisconsin DNR biologists reintroduced 139 martens from northern Minnesota into the Chequamegon National Forest in northwestern Wisconsin.

Since the 1990's the Great Lakes Indian Fish and Wildlife Commission has conducted radio telemetry research on marten in the Chequamegon-Nicolet National Forest.

The DNR's Bureaus of Endangered Resources, Wildlife Management, and Integrated Science Services, in cooperation with the U.S. Forest Service and other agencies and stakeholders, implemented an American Marten Recovery Plan in 1986. The recovery plan established a self-sustaining population goal of 300 marten on the Nicolet side and a reintroduction goal of 100 marten on the Chequamegon side of the National Forest by 1990. It appears these goals were achieved. Presently, the DNR is updating the recovery plan based on recent information collected and an improved marten knowledge base.

Biologists are conducting studies of existing populations, habitat quality and other factors. Currently, the DNR and the University of Wisconsin at Stevens Point are conducting a mark-recapture study to estimate the population size on Nicolet side of the National Forest. In addition, telemetry data from radio-collared juveniles will provide information on dispersal, survival, and habitats being used. The findings of this two year study will help guide management decisions. The DNR provides trapper education courses and a trapping pamphlet that discussed the trapping regulations for marten. Knowledge about the Marten Restoration Areas, live-trapping methods, and marten ecology help to limit the number of marten accidentally trapped. Additionally, the DNR has developed an informational pamphlet about the marten to improve the understanding and awareness of this state endangered species.



American Marten

Marten in Spruce Tree.

Photo ©  USFWS.

American Marten

The once extirpated American marten has been reintroduced to WI at several locations, all within the North Central Forest.

Photo © Erwin and Peggy Bauer.

American Marten

American Marten

Photo © A.B. Sheldon.

American Marten

American Marten

Photo © A.B. Sheldon.

Wildlife Action Plan

Wisconsin Wildlife Action Plan graphic

Natural community (habitat) associations

The table below lists the natural communities that are associated with American Marten. Only natural communities for which American Marten is "high" (score=3) or "moderate" (score=2) associated are shown. See the key to association scores for complete definitions. Please see the Wildlife Action Plan to learn how this information was developed.

Ecological landscape associations

The table below lists the ecological landscape association scores for American Marten. The scores correspond to the map (3=High, 2=Moderate, 1=Low, 0=None). For more information, please see the Wildlife Action Plan.

This map shows the probability of American Marten occurring in each of Wisconsin's Ecological Landscapes.  Actual scores can be found in the table to the left.

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Landscape-Community combinations of highest ecological priority*

Ecological priorities are the combinations of natural communities and ecological landscapes that provide Wisconsin's best opportunities to conserve important habitats for a given Species of Greatest Conservation Need. The 10 highest scoring combinations are considered ecological priorities and are listed below. More than 10 combinations are listed if multiple combinations tied for 10th place. For more information, please see the Wildlife Action Plan.

* Ecological priority score is a relative measure that is not meant for comparison between species. This score does not consider socio-economical factors that may dictate protection and/or management priorities differently than those determined solely by ecological analysis. Further, a low ecological priority score does not imply that management or preservation should not occur on a site if there are important reasons for doing so locally.

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Issues/threats and conservation actions

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the WWAP because lack of information can threaten our ability to successfully preserve and care for natural resources.

Threats/issues and conservations actions for rare animals

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Last revised: Thursday, October 08, 2020