Variety of habitats, including meadows, fields,
brushy areas, and open woods. Avoids dense
forest, prefers ecotones. Abundance of small
mammals is important in determining the local
distribution of least weasels.
Feeds almost entirely on mice. Small enough to
pursue rodents into runways, burrows, and nest
Most active at night. With abundant food
sometimes produces more than one litter per year.
Breeds year round; young born any time of the year;
delayed implantation does not occur; litter size
usually 4 to 5.
Much smaller than the short or long-tailed weasel.
Both short and long-tailed weasels have a blac
The least weasel is considerable smaller, with a very
short tail, and males may measure up to 8 inches in
length, while females measure about 6 inches.
The least weasel also has a
long, slender, muscular body with short legs. The head
is small, with beady eyes, small ears and a pointed
nose. They move with quick movements and a graceful,
bounding gait. All three weasels change color with the
seasons, and there is no color difference between the
sexes. All the senses are well developed in the weasel.
The least weasel lacks the black
tipped tail of the other two species.
Both the short tailed and long tailed weasel females
mature at 3 to 4 months and males mature at about one
year. The breeding season is in July. There is a period
of delayed implantation with a gestation period of 9 to
10 months. The period of active pregnancy is 23 to 17
Litter sizes varies from four to
thirteen, with an average of six to eight. The young are
born in April or May in nests constructed in underground
dens or hay piles. Mouse nests and burrows are often
used and heavily lined with fine grass and mouse fur.
The male begins to bring food to the den about 1 month
after the young are born. The young are weaned at the
end of 5 weeks and are able to hunt for themselves by 7
or 8 weeks of age. The family stays together until late
summer and then disperses. The life expectancy of
weasels is short, probably less than a year, although
they are capable of living as long as 6 years.
The least weasel may have three
to ten young, but averages five which may be born at any
time of the year but most frequently are born in late
prey on small rodents such as mice, rats, voles, hares,
rabbits, and chipmunks. They also take shrews, birds,
birds eggs, frogs, bats, insects, earthworms and may
occasionally kill domestic chickens. The least weasel
depends almost exclusively on mice for food.
The weasel hunts by tirelessly
and persistently investigating every small hole,
crevice, bush or rock pile it encounters. They will
track prey by following their scent trails and generally
attack prey by ambushing and pouncing on it. They are
very quick and kill by piercing the base of the skull
with their teeth. The weasel frequently kills more than
it can eat and often caches leftover food. The weasel
can consume up to one third of its own weight in a 24
Weasels are curious, alert and bold. They are persistent
hunters who seldom remain long in their dens and may be
abroad hunting at any hour, although they are usually
most active at night. Weasels are active year round.
Weasels occasionally hunt in pairs but, for the most
part, are solitary except during breeding and rearing
season. They are good swimmers and can also climb trees.
All species emit a strong musk odor when alarmed, and
the weasel may stamp its feet when annoyed. Weasels may
mark their trails with droppings. Home ranges very from
30 to 400 acres.
Weasel populations often cycle with mouse populations.
Several parasites can infect weasels, such as guinea
worm and kidney worms. These probably have little impact
on the population.
Weasels are subject to predation
from hawks, owls, foxes, coyotes, dogs, cats and man.
In agricultural areas, weasels
are more common due to the practice of storing grain
which provides ideal conditions for mice.
Weasels prefer woodlands or open country with hedgerows,
thickets or fence rows. They are usually found near
water but are not semi-aquatic as is the mink. They
frequent stone piles, brush heaps, wood piles, hay
stacks, log piles and old abandoned buildings.
The least weasel has a variety
of habitats including meadows, fields, brushy areas, and
open woods. It avoids dense forests.
The dens of weasels are shallow
chambers about 6 inches underground with two to three
entrances and are lined with mouse fur and grass.
The fur of the least weasel is seldom taken and is so
small that it is of little or no value in the fur trade.
Weasels play an important role
in helping to control rodent populations.
Best Management Practices