286 Marmota monaxbe a signal for the time when spring crops might be planted.
When Europeans immigrated to North America, the wood-
chuck was selected as a proxy in the absence of the com-
monly used species in their homeland.
Males often emerge earlier than females; mating occurs
soon after females arouse and emerge from hibernation. The
mating system is polygynous. Each year 50–80 percent of
adult females may reproduce; yearling females can repro-
duce, but usually in lower proportions than adults. As many
as nine—but typically three to fi ve—young are born in the
burrow after a gestation of 31–32 days. The young emerge
from the burrow after 5–6 weeks, in early summer to mid-
summer. Most juveniles disperse from their natal area at the
end of their fi rst growing season; however some (especially
females) remain near their natal area. Although independent
after dispersal, woodchucks continue to grow for two to
three years before achieving adult body size. Annual cycles of
fat deposition in preparation for hibernation changed after
two years when individuals were transported to the South-
ern Hemisphere. Woodchucks are generalist herbivores and
eat an incredible diversity of forbs, grasses, sedges, fl owers,
fruits, and buds. They can climb trees to consume leaves and
(occasionally) fruits or soft seeds. They will feed on orchard
fruits and the vegetation in hayfi elds. They sometimes are
known to eat insects and to scavenge small vertebrates.
Adults are solitary and territorial. Male home ranges vary
from 0.5 to 4.0 ha, with female home ranges being about half
that size. Females, in particular, tend to overlap only a little in
their home ranges, whereas the overlap between males and
females is more signifi cant. Because individuals are relatively
asocial, interactions among adults are typically agonistic.
Kin ship does infl uence interactions, however, and close rela-
tives demonstrate slightly more amicable and slightly less ag-
gressive interactions toward each other. Olfactory communi-
cation appears important to woodchucks; they scent-mark on
structures and plants using well-developed glands in the up-
per lip and the corner of the mouth. Vocalizations are less
varied in woodchucks than in marmot species that are more
social. Calls are rarely given, and the woodchucks’ high-
pitched alarms are probably to warn off spring of potential
dangers. Their predators include most raptors, felids, canids,
and large mustelids that occur within the distribution area
of M. monax. Woodchucks are hunted for food and sport in
much of their range. They are considered a nuisance on golf
courses and in urban areas, where they dig under structures.
In orchards and croplands, M. monax can cause considerable
crop losses in local settings.
general references: Anonymous 1990; Caire and Sloan
1996; Jordheim 1990; Kaufman and Kaufman 2002; Kwiecin-
ski 1998; Maher 2009; Roehrs and Genoways 2004; S. S. Rob-
inson and Lee 1980; Stevenson 1990; Tumlinson et al. 2001;
Zervanos et al. 2010.Marmota olympus (Merriam, 1898)
Olympic Marmotdescription: The Olympic marmot has a yellow brown to
light brown dorsum, with a long and densely haired tail of
similar color. The snout is white, and a white band often ex-
tends back to between the eyes. The venter is similar in col-
oration to the dorsum but can be more rufous or gray. The
dorsal pelage appears to fade to yellow over the summer.size: Male—HB 740 mm (720–750 mm); T 219 mm (210–237
mm); Mass 4100 g (4100–4300 g; n = 6) after hibernation,
9300 g (8500–11000 g; n = 5) before hibernation.
Female—HB 680 mm (670–690 mm); T 186 mm (180–192
mm); Mass 3100 g (2700–3500 g; n = 4) after hibernation,
7100 g (6700–7500 g; n = 6) before hibernation.
Male-biased sexual dimorphism is apparent.distribution: This species is endemic to the Olympic
Mountains of western Washington (USA).geographic variation: None.