American Marten Monitoring Project

Important Information on American Marten Monitoring Project

MartenProject Goal: To gain a better understanding of the population status and distribution in New Hampshire and assess threats to future population sustainability.

Timeline: When European settlers began to colonize in New Hampshire furbearers were plentiful. Beaver dams were sought out to use as stream crossings as the first roads were built and beaver meadows were used as grazing areas for cattle. As the colonists moved north forests were cut down and turned into farm fields and the first business in the state was the fur trade (Silver 1957). This conversion of habitat combined with unregulated trapping led to the decline of American marten, also called pine marten (Martes Americana), a member of the mustelid family and closely related to fisher (Martes pennanti) and mink (Mustela vison). In an attempt to protect the remaining population, the New Hampshire legislature eliminated marten trapping statewide in 1935 (Silver 1957).

Reintroduction attempts took place in 1953 and again in 1975 however, marten sightings remained scarce. A lack of surveys to evaluate the success or failure of these reintroduction attempts combined with a general lack of observations led to American marten being one of the first species added to the state’s newly adopted list of Threatened and Endangered Species in 1979 (Kelly, 2005).

In the early 2000s the Nongame and Endangered Wildlife Program at N.H. Fish and Game partnered with the University of Massachusetts to assess the status and distribution of American marten in New Hampshire. Researchers used Geographic Information Systems (GIS) to map 157 records of marten observations and undertook a live trap effort. Biological information was collected from trapped animals, incidental captures by recreational trappers and road kill. Ultimately, they found that American marten occurred from the White Mountain National Forest to the northern-most town of Pittsburg on the Canadian border. In addition, researchers reported finding both males and females as well as both juveniles and adults, which were all good indicators of reproduction taking place (Kelly, 2005).

In 2013, new research with the University of New Hampshire was completed which investigated the impacts of wind farm development on American marten. Marten require large blocks of unfragmented forests and are often considered an umbrella species because their territories can cover many different forest types which also provides habitat for a variety of other wildlife species.

This research was funded in part by Granite Reliable Power, the developer of 33 wind turbines built along the high elevation ridgeline in Millsfield and Dixville, and consisted of pre-construction and post-construction surveys to determine any changes in behavior or habitat use by wildlife.

American marten were live-trapped, radio-collared and marked with small ear tags to allow researchers to study their habitat use, movements and home range sizes. Trail cameras were set up to document the presence of additional marten and snow track surveys were conducted to document the presence of other wildlife within the study area before, during and after wind tower construction (Siren, 2013).

In 2017, as a result of all this work, American marten were removed from the list of threatened species in New Hampshire. Ongoing monitoring will be done to ensure the continued recovery of this species.

Outcomes: American marten are now known to occur from the White Mountain National Forest north to the Canadian border. Research has confirmed the presence of both males and females of various age classes indicating natural reproduction taking place in the wild. An estimate of the population size is still unknown.

Researchers investigating the impact of wind farm construction on American marten found that during the construction phase, marten were periodically displaced and used the study area less. Although proximity did not return to that of the pre-construction period, it did gradually increase after construction ended, suggesting that marten were adjusting to the new site conditions.

A significant finding was related to an increase in predators and competitors. Researchers documented an increase of red fox and coyotes in the study area following construction, likely due to maintained roads and snowmobile trails that provided easy access into high elevation habitats that otherwise would not have been used. The direct loss of mature spruce-fir forest, combined with changes in plant and animal communities, and how wildlife are impacted by the operation of the wind turbines remains to be seen.

Location: White Mountain National Forest and north to Canadian border.

Partners: U.S. Forest Service, recreational trappers, University of Massachusetts, University of New Hampshire, Granite Reliable Power

Funding: Private donations have provided the foundation for the Nongame and Endangered Wildlife Program since its inception in 1988. Contributions support the on-the-ground work and also enable the Nongame Program to qualify for additional funding through grants from both the State of New Hampshire and the U.S. Fish and Wildlife Service. Donations made to the Nongame Program are matched dollar-for-dollar by the State of New Hampshire up to $50,000 annually. Please help keep this project going by donating to the Nongame and Endangered Wildlife Program.

The Nongame Program also receives a portion of proceeds from the sale of the NH Conservation License plate (moose plate) each year. To learn more please visit the NH Moose Plate Program online at

Federal funds called State Wildlife Grants also provide essential funding for the Nongame Program.

Volunteering: Observations of American marten can be submitted to the Wildlife Division at NH Fish and game via email at:


  • Kelly, J. 2005. Recent Distribution And Population Characteristics Of American Marten In New Hampshire And Potential Factors Affecting Their Occurrence Thesis. Master of Science in Wildlife and Fisheries Conservation. University of Massachusetts. Amherst.
  • New Hampshire Game and Furbearers. 1957. Helenette Silver. Published by the New Hampshire Fish and Game Department. Concord, NH.
  • Siren, A. 2013. Population Ecology Of American Marten In New Hampshire: Impact Of Wind Farm Development In High Elevation HabitatThesis. Master of Science in Natural Resources: Wildlife and Conservation Biology. University of New Hampshire. Durham.