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American Marten (Martes
americana)
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Description:
Marten are largely nocturnal, medium-sized carnivores in the weasel
family (Mustelidae). The major identification challenge is distinguishing
marten from fishers, as they are found in similar habitat in trees
and on the ground, and both have thick fur and bushy tails.
Marten are much smaller than fishers and have orange on their
throat and chest, which fishers lack. In addition, marten ears and
snout appear pointier than fishers.
Size:
Measurements from Minnesota are from Hazard (1982), from Wisconsin
are from Jackson (1961), and from the Eastern United States are
from Hamilton and Whitaker (1998).
Total length averaged 24.2 (615 mm) in Minnesota, ranged
from 23.6 to 26.6 (600-675 mm) in Wisconsin, and ranged
from 21.7 to 25.6 (551-650 mm) in the Eastern United
States.
Tail length averaged 7.7 (195 mm) in Minnesota, ranged from
7.5 to 8.7 (190-220 mm) in Wisconsin, and ranged from
5.9 to 8.1 (150-205 mm) in the Eastern United States.
Female body weight ranged from 1.5 to 2.2 pounds (0.7-1.0 kg) in
Wisconsin, and from 1.3 to 1.8 pounds (0.6-0.8 kg) in the Eastern
United States.
Male body weight ranged from 2.2 to 3.1 pounds (1.0-1.4 kg) in
Wisconsin, and from 2.4 to 2.9 pounds (1.1-1.3 kg) in the Eastern
United States.
Males are typically larger than females.
Distribution & Status:
Marten are found in forested regions throughout Alaska and Canada
to just south of the conifer tree line in the U.S. (Hazard, 1982;
Ruggiero et al., 1994). Martens were trapped for their fur
and were extirpated from the lower Great Lakes region in 1925 (De
Vos, 1964). Regionally, marten can be found in northeast Minnesota,
Ontario, Michigan, and Wisconsin; this current distribution encompasses
80% of their historical range (Laliberte and Ripple, 2004; Moen
et al., 2014). Marten have state endangered status in Wisconsin.
Populations are secure in Ontario and Minnesota, vulnerable in Michigan,
imperiled in Wisconsin, and are presumed extirpated from North Dakota.
Worldwide, Martes americana is restricted to northern North
America. Other Martes species occur throughout Europe and
Asia.
Marten have an IUCN rank of Least Concern, IUCN
information.
Life History:
Marten diet consists primarily of snowshoe hare (Lepus americanus)
and squirrels (Sciuridae), supplemented by other small mammals,
birds, insects, fruits, and berries (Clark et al., 1987;
Drew and Bissonette, 1997; Gosse et al., 2005). The marten
is mostly associated with climax conifer forests and other mature
hardwoods and requires large amounts of undergrowth and canopy cover
(Wright, 1999; Wilbert et al., 2000; Godbout and Ouellet,
2007). Marten mate in mid-summer, but zygotes do not implant in
females until mid-winter due to delayed implantation. Females bear
2-6 young from March to May (average 3-4 kits) after a 60 day gestation,
and can mate in their second summer (Hamilton and Whitaker, 1998).
Dens are usually in bushes, hollow logs, trees, and rock crevices.
Kits can open their eyes at 6 weeks, are ready to leave the nest
at 2 months, and disperse in the fall. Marten are prey for raptors
and larger mammal carnivores.
Reduced amounts of snow will affect marten distribution (Waltari
and Guralnick, 2009). Deep snow gives the marten a competitive advantage
over the fisher (M. pennanti) in winter periods (Raine, 1983;
Krohn et al., 2004; Waltari and Guralnick, 2009). In montane
areas, the marten is expected lose part of its lower elevation range
and be more concentrated at higher elevations (Johnston et al.,
2012). This loss is expected to reduce genetic diversity, connectivity
of populations, and hinder the ability to disperse (Wasserman et
al., 2013).
Contacts with Humans:
Fur-trapping can be a major source of mortality. Since marten require
forested habitat, they are uncommon near farms and are little threat
to poultry. Loss of forested habitat from logging combined with
fur-trapping harvest can be expected to reduce marten abundance.
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