History of martens in Michigan’s Lower Peninsula
• American martens once ranged throughout Michigan as far south as Allegan County, following the distribution of northern coniferous forests.
• Marten populations declined sharply in the 19th and early 20th century, as a result of widespread timber harvest, widespread fires, and overharvest for fur.
• The last known sighting of a marten in the Lower Peninsula was 1911 in Montmorency County.
• In 1985-1986 the Michigan Department of Natural Resources and the U.S. Forest Service reintroduced martens into the Lower Peninsula from the Crown Chapleau Game Preserve in Ontario, Canada.
• Thirty-six martens (16 females and 20 males) were released into the Manistee National Forest and Pere-Marquette State Forest.
• Forty-nine martens (24 females and 25 males) were released into the Pigeon River Country State Forest.
• Martens were listed as a state threatened species in 1978, but were removed in 1999. Marten populations in the Upper Peninsula have reached levels permitting harvest in 2000. Trapping is still not permitted in the Lower Peninsula.
This information was obtained from:
Williams, B.W., J.H. Gilbert, and P.A. Zollner. 2007. Historical perspective on the reintroduction of the fisher and American marten in Michigan and Wisconsin. Gen. Tech. Rep. NRS-5. Newtown Square. PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 29 p.
Marten information
• Adult martens weigh between 1.3 – 3.3 pounds and are 22 – 26 inches in total length (7 – 8 inches of this is tail). Females are generally about two-thirds the size of males.
• Martens are members of the weasel family, and they have the long slim body of weasels, about the same size as a mink.
• Martens have golden to dark brown fur, with a highly variable throat patch ranging from light brown to yellow or bright orange. Their ears are rimmed in gray to white and their faces may be lighter in color as well.
• Historically, martens were associated with mature, boreal, coniferous forests (spruce, fir, and pine forests). Ideal habitat includes many large trees and a complex understory with lots of downed wood, which provides cover for martens and suitable habitat for its prey.
• Martens can be active at any time, but are most active around dawn and dusk. In warmer weather, it is common for them to rest in trees during the day. As temperatures fall, they are more likely to use tree cavities for sheltering.
• Home range size for martens in our study area is generally 1 – 4 square miles.
• Martens are omnivores, their diet contains small mammals, squirrels, birds, reptiles, amphibians, insects, and carrion when available. They also will consume berries when they are available in the summer and fall.
• Martens are active all year long and will hunt underneath snow for prey during the winter.
• Martens breed in mid/late summer, generally July in our study area, but any resulting embryos do not implant until early spring. Gestation is 27 days and 1-4 kits are generally born in April or May. Weaning occurs around 39 days and young reach adult size within 3 – 4 months. Young are capable of breeding in their second year.
This information was obtained from:
Kurta, A. 2017. Mammals of the Great Lakes region, 3rd edition. University of Michigan Press: Ann Arbor, 416p.
Similar species that might be confused with martens in Michigan
Fishers are larger members of the weasel family, found in the Upper Peninsula, but at least a couple of individuals have been sighted in the Lower Peninsula in recent years. Fishers weigh between 4 – 12 pounds and are 31 – 42 inches in total length (11 – 16 inches of this is tail). Martens weigh between 1.3 – 3.3 pounds and are 22 – 26 inches in total length (7 – 8 inches of this is tail). Fishers have coarser fur than martens and their abdomen is similar in color to their backs, a darkish brown, though they may have variable white markings on their abdomen.
Mink are generally the same size as martens, weighing 1.3 – 2.9 pounds and are 19 – 27 inches in total length (5 – 9 inches of this is tail). Mink are a more uniform chocolate brown on their back and abdomen, and they often have a white chin and variable amounts of white on their abdomen. In addition, mink are generally found near water. Long-tailed weasels and ermine (not pictured) are both smaller than martens, both have distinctly darker backs than abdomens (this photo overexposed because of the lightness of the long-tails abdomen). Long-tailed weasels are slightly larger than ermine, weighing 3 – 10 ounces and are 11 – 17 inches in total length (3 – 6 inches of this is tail). Their backs are cinnamon brown and their abdomens are yellowish in summer and in winter they molt to white, with a black tail tip.
Eastern gray squirrels are about the only other species that might be confused for a marten. In our region, many individuals are melanistic (darker than normal) and this is variable among individuals with some being almost black, to just slightly darker than normal. Eastern gray squirrels weigh 0.75 – 1.5 pounds and are 17 – 20 inches in total length (7 – 10 inches of this is tail). Their tails are much bigger and bushier than marten tails.