Martes americana
American Marten
Troy Radtke
Description
The American marten (Martes americana) is commonly referred to as the
American marten or the pine marten. This carnivore is a member of the family mustelidae.
It resembles a small house cat with shorter legs, a bushy tail, and a more slender body with
dark brown fur. Martens show sexual dimorphism with the males generally slightly larger
than the females (Smith and Schaefer, 2002).
Fossil History and Distribution
Marten fossils do not appear until the middle Pliocene in Poland. The subgenus
Martes did not appear in North America until the late Pliocene (Stone and Cook accessed
21 October, 2003). The marten usually inhabits relatively unfragmented mature coniferous
forests but is sometimes also found in mixed conifer/deciduous forests. It is found
throughout Canada’s and Alaska’s forested regions. They are also found in the northern
part of the United States such as Minnesota, Maine, and New York, and in the Rocky
Mountains (Kurta, 2001). Before the logging movement, northern Wisconsin had optimal
habitat for martens. Trapping and habitat destruction in the form of logging led to the
extirpation of the marten in Wisconsin by 1939 and has led to a decline in their numbers
and distribution throughout their range. Between 1975 and 1983, the Wisconsin
Department of Natural Resources and the U.S. Forest Service released 172 marten in the
Nicolet Forest in northeastern Wisconsin. Between 1987 and 1990, the Wisconsin DNR
released 139 more animals in the Chequamegon National Forest in the northwestern part of
the state (Wisconsin DNR accessed 21 October, 2003). These two populations remain
separate and DNR estimates put the current population size at 500 to 1000 animals (Fig. 1).
However, there is evidence that the population in the northwest is declining. But, with
limited surveying and data, it is still uncertain. Winter DNR surveys in 2004 should reveal
more about their ranges and population sizes in Wisconsin (Dr. Kevin Russell, personal
communication 23 Oct. 2003).
Figure 1. Marten Distribution in Wisconsin (Wisconsin Department of Natural Resources
accessed October 21, 2003).
Ontogeny and Reproduction
Martens do not reproduce until they are two years old. They mate in July or August
but experience delayed implantation and development of the embryo stops until the
beginning of March. Young are born in late March or April. Litter size is usually 2-3
(Kurta, 2001). They are weaned at 6-7 weeks and disperse and set up their own territories
in the fall (Wisconsin Department of Natural Resources accessed 21 October, 2003).
Ecology and Behavior
Martens are generally nocturnal. Their nocturnal activity is thought to help them
avoid predation, especially from avian predators. However, martens in the northern part of
their range may be diurnal during the winter. Although martens live in relatively cold
climates, they have few morphological or physiological adaptations to the cold and this
daytime activity for those in the north helps them avoid the cold temperatures in winter
(Drew and Bissonette, 1997).
Martens will become inactive either because of extreme cold or because of the high
cost of locomotion after a heavy snowfall. The most thermally efficient place for marten to
remain inactive is below the snow (subnivean). Forests that have a lot of coarse woody
debris or lower branches on or near the ground provide access to subnivean resting
locations by creating air pockets in the snow. Martens in winter prefer to rest in subnivean
locations, but they may also rest in trees, usually conifers (Wilbert et al., 2000). In
addition martens rest in logs, rock crevices, and any other spot that offers them
concealment (Ruggiero et al., 1998).
Martens are carnivorous. They hunt primarily subnivean (Drew and Bissonette,
1997). The coarse woody debris that they use for denning and resting is also where they
spend much of their time hunting for small mammals. Although voles and other small
mammals seem to be the most common prey items, it is the grouse, squirrels, and snowshoe
hares that make up the vast majority of calories consumed and consequently energy intake.
They will also eat fruit, insects, and vegetation, although more commonly in the summer
(Cumberland et al., 2001).
Its home range size is about 1 km2 for females and about 2-4 km2 for males (Kurta,
2001).
Remarks
The marten is well established in the neighboring state of Minnesota as well as
northeast states like Maine. These states have a habitat similar to Wisconsin, yet in
Wisconsin the population is struggling. The reason for this is still undetermined.
Currently, the two core areas where marten live in Wisconsin are closed to dry land
trapping in order to avoid accidental marten catches by trappers and help the population to
get established.
Marten are still trapped for their fur throughout Canada and in a few states in the
United States.
Literature Cited
Cumberland, R.E., J.A. Dempsy, and G.J. Forbes. 2001 Should diet be based on biomass?
Importance of larger prey to the American marten. Wildlife Society Bulletin,
29(4) 1125-1130.
Drew, S.G., and John A. Bissonette. 1997 Winter Activity patterns of American martens
(Martes americana): rejection of the hypothesis of thermal-cost minimization.
Canadian Journal of Zoology, 75(5) 812-816.
Kurta, Allen. 2001 Mammals of the Great Lakes Region. University of Michigan Press.
223-226.
Ruggiero, L.F., D.E. Pearson, and S.E. Henry. 1998 Characteristics of American marten
den sites in Wyoming. Journal of Wildlife Management, 62(2) 663-673.
Russell, K. 23 October, 2003.
Smith, A.C., and J.A. Schaefer. 2002 Home range size and habitat selection by American
Marten (Martes Americana) in Labrador. Canadian Journal of Zoology, 80(9)
1602-1609.
Stone, K.D., and J.A. Cook. Molecular evolution of Holarctic martens (genus Martes,
Mammalia: Carnivora: Mustelidae)
<http://www.sou.edu/biology/Faculty/Stone/images/Molecular%20evolution%
20of%20martens.pdf> 23 October, 2003.
Wilbert, C.J., S.W. Burskirk, and K.G. Gerow. 2000. Effects of weather and snow on
habitat selection of American martens (Martes americana). Canadian Journal of
Zoology, 78(10) 1691-1696.
Wisconsin Department of Natural Resources. American Marten.
<http://www.dnr.state.wi.us/org/land/er/factsheets/mammals/Marten.htm> 23
October, 2003.
Reference written by Troy Radtke, Biology 378 student. Edited by Christopher Yahnke.
Page last updated.