Weasel Family

Classification: Non-game Wildlife Species

Mustela nivalis

Order: Carnivora
Family: Mustelidae

Status: Unprotected predator.

Identifying Characteristics: The smallest weasel and smallest carnivore in North America.  Similar to other weasels in color and body form.  Males are larger than females.  Fur is brown above and whitish below during summer.  Entirely white during winter.  No black tip at end of short tail  Total length: less than 10 inches.  Weight: 1 to 3 ounces.

Habitat: 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.

Food Habits: Feeds almost entirely on mice.  Small enough to pursue rodents into runways, burrows, and nest chambers.

Life History: 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.

Similar Species: Much smaller than the short or long-tailed weasel.  Both short and long-tailed weasels have a black tip on tail.

Characteristics
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.

Life Cycle
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 days.

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 winter.

Food
Weasels 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 hour period.

Habits
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.

Population
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.

Habitat
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.

Economic Value
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.

NOTICES

The MTA Board of Directors will meet December 7, 2014 in Lewistown at the Yogo Inn. MTA members are encouraged to attend.

Deadline for articles, pictures and other information for the Winter newsletter is December 20, 2014. Articles received after that date will not be printed. To forward your report or for more information

Click Here

LATEST NEWS

2014 Rendezvous Photo Gallery

View Here

2014 Rendezvous Raffle and Winners List

View Here

First Annual Bitterroot Area Trappers Appreciation Camp-Out a Success!

Read Here

I-169 and All Other Citizen Inititives Do Not Make Montana's November Ballot

Read Here

Did You Know?

James Felix "Jim" Bridger (March 17, 1804 – July 17, 1881) was among the foremost mountain men, trappers, scouts and guides who explored and trapped the Western United States during the decades of 1820-1850, as well as mediating between native tribes and encroaching whites. He was of English ancestry, and his family had been in North America since the early colonial period.

 

The Hudson's Bay Company was started in 1670 along the James and Hudson Bays. Natives would barter furs for trade goods such as knives, beads, needles and blankets. HBC company is in their 4th Century of retail and still going strong.

 

Robert Campbell (1804-1879) was an American frontiersman, fur trader and businessman. He joined a fur trapping expedition to Rocky Mountains in 1825 with Jedediah Smith, Moses Harris, and Jim Beckwourth. He continued as a trapper and trader through most of the mountain man era.

 

Fort Leavenworth, 1867, was the first settlement in Kansas territory and is the oldest active Army post west of the Mississippi River. The fort initially served as a quartermaster depot, arsenal, and troop post, and was dedicated to protecting the fur trade and safeguarding commerce on the Santa Fe Trail.

 

From 1828-1867 Fort Union was the most important fur trading post on the Upper Missouri. Here, seven Northern Plains Indian Tribes, including the Assiniboine, traded buffalo robes and other furs for goods such as cloth, guns, blankets and beads. This fort was a bastion of peaceful coexistence, annually trading over 25,000 buffalo robes and $100,000 of merchandise.

 

The Mountain Men explored and opened up the Rocky Mountain region. The Rocky Mountain Fur Company (1822-1834) established the brigade system, with teams of trappers working together. In one year they could earn half a million dollars in pelts. Eventually they were outdone by Astor's American Fur Company. By 1834, the fur trade was being played out; Astor's and the Hudson's Bay trappers were all tough competitors.