A once present member of the weasel family might just be making a comeback in Pennsylvania.
A Quick History in Pennsylvania
The American Marten, also known as the Pine Marten, could historically be found in the northern forests of Pennsylvania. Due to rampant timber harvesting and a near statewide deforestation between 1650-1920, along with unregulated harvest of the mammal, Martens were extirpated from the state by the beginning of the 20th century.
Genealogy: The little guys on the block
The American Marten, often mistaken for other members of the weasel family (think Mink or Fisher) comes in on the small side. A typical specimen will range from 19-27 inches long and weigh between 1-3 pounds. As with most mammal species, males tend to be heavier (65%) and longer (15%) than females. They have light brown or black hair on their back and legs with a yellowish-orange bib of fur extending from their face to the chest. Their 5 finger paws allow them a great amount of dexterity, just like other members of the weasel family.
Range: Habitat knows best
Historically, the American Marten range extended from the Northeast, through Canada, to the Pacific coast. Included in this range is the upper Midwest, Rocky Mountains, and extending through the northern Appalachian range, into as south as Tennessee. Outside of a few small reintroduction populations in Maine, Vermont, Wisconsin, Michigan, and South Dakota, most of the southern portion of their historic range is currently occupied.
Quality of habitat is the main driver in where American Martens can be found. With a home range of 2-6 miles, where males do not overlap with other males, there needs to be ample room to roam. They prefer mature stands of forest that contain a strong population of conifers. This mature stand of timber must, however, contain a diverse and complex structure in both the canopy and forest floor. Optimal habitat will have less than 30% fragmentation and which can be verified through their avoidance of clearcuts within timber stands.
Diet: What do they really eat?
The diet of the American Marten can best be classified as opportunistic foragers with their selections showing a generalist make up. Unlike many of the anecdotal stories you will hear about what they eat, the bulk of their diet consists of small mammals such as voles, mice, and shrews. The next highest choice consists of insects, fish, and amphibians, followed closely by plant material; both soft and hard mast. Birds and Squirrels make up a relatively small percentage of their diet. Will an American Marten eat a Ruffed Grouse or Turkey eggs? Yes, but they tend not to seek out these types of food sources. Opting, instead, for a diet rich in understory rodents and plant material.
Reintroduction: How would it work?
With all this information in mind, the Pennsylvania Game Commission has proposed a reintroduction plan for the American Marten. This effort has been led by Furbearer Biologist Tom Keller. After conducting a feasibility study, the PGC has determined that the American Marten can be reintroduced to select locations within the state successfully. Items that have been considered in the feasibility study include dietary needs, impact on other wildlife, and habitat suitability. According to the study, the areas most likely to have success include the PA Wilds region, Laurel Highlands, and the Ridge and Valley areas of the state. Much of the habitat that is suitable for reintroduction can be found in National Forest, State Forest, and State Game Lands. This reduces the need for private landowners to be concerned about how activities on their land will be impacted by the addition of the American Marten to the landscape.
To hear Tom Keller talk about the reintroduction process, listen to Ep 146: The American Marten, a Reintroduction Plan in PA of the Conservation Unfiltered podcast
To read the PA Marten Reintroduction Feasibility Assessment 2022, click here