Arctic Shrew

Arctic Shrew

Blackback shrew, Saddlebacked shrew

Kingdom
Phylum
Subphylum
Class
Order
Family
Genus
SPECIES
Sorex arcticus
Population size
Unknown
Life Span
18 mos
WEIGHT
5-13 g
LENGTH
10-12 cm

The Arctic shrew is most distinctive in its tri-colored fur. It is dark brown or black on its back from its head to the base of its tail, while its flanks are a lighter brown, and its underside is lighter still grayish brown. Even its tail is bi-colored, dark brown on the dorsal side, and gradually fading to a lighter brown on the ventral side. The fur is grayer in wintertime, and its tricolor is most marked during the winter months from October to June, for the fur is thicker and brighter. Arctic shrews molt twice a year, and the tricolor bands in the fur are less prominent in younger shrews.

Di

Diurnal

No

Nocturnal

Cr

Crepuscular

Ca

Carnivore

In

Insectivores

Te

Terrestrial

Pr

Predator

Al

Altricial

Te

Territorial

So

Solitary

No

Not a migrant

A

starts with

Distribution

Geography

Continents
Introduced Countries
Biogeographical realms
WWF Biomes

Arctic shrews are native to North America, ranging from the Arctic Circle in the north and as far south as the northern United States, into North and South Dakota, Wisconsin, Michigan, and Minnesota. Their eastern limits are in eastern Quebec and the Atlantic Maritime provinces, and their western limits are the southern Yukon and Mackenzie valleys. These small animals live in areas near bodies of water, such as lakes, streams, marshes, wetlands, bogs, swamps, ditches, or open areas near wetlands. Arctic shrews can be found in clearings in boreal forests, and occasionally in mixed conifer swamps, dry or old fields, dense grasses near ditches, mixed grasses, in the undergrowth of forest clearings, alder thickets, and dry marsh with grasses, sedge hammocks, forbs, cattail, willow, and red-osier shrubs.

Arctic Shrew habitat map

Climate zones

Habits and Lifestyle

Arctic shrews are solitary territorial animals. They are active during the day and night. Arctic shrews are very active and move quickly. Periods of inactivity are spent lying on the ground, either on one side or with the ventral side down, body rolled up, and head tucked under the body. They also groom themselves by wiping the forefeet rapidly along the mouth.

Group name
Seasonal behavior

Diet and Nutrition

Arctic shrews are carnivores (insectivores). They eat insects, worms, and small invertebrates, with a large proportion of their diet made up of larch sawflies.

Mating Habits

REPRODUCTION SEASON
varies with location
PREGNANCY DURATION
13-21 days
BABY CARRYING
4-10 young
INDEPENDENT AGE
5-6.5 weeks
FEMALE NAME
sow
MALE NAME
boar
BABY NAME
shrewlet

There is little information about the mating habits of the Arctic shrew; however males of most shrew species mate with many females, and compete with other males for females, so the assumption is that Arctic shrews behave similarly. In Wisconsin, the breeding season lasts from February to August, and the breeding season is shorter in more northern areas, from April to August. Females give birth to one or two litters each year, and these litters range in size from 4 to 10 offspring, with an average of 7 offspring per litter. The gestation period ranges between 13 and 21 days, so the young stay with their mother until 5 to 6.5 weeks after conception, and males make no contribution to parental care. When they are born, young Arctic shrews are helpless. Their mother cares for them until the end of the weaning period, 20 to 24 days after birth. Both female and male Arctic shrews reach reproductive maturity after one year.

Population

Population threats

Arctic shrews do not face any major threats at present.

Population number

According to IUCN, the Arctic shrew is widespread throughout its range but no overall population estimate is available. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.

References

1. Arctic Shrew on Wikipedia - https://en.wikipedia.org/wiki/Arctic_shrew
2. Arctic Shrew on The IUCN Red List site - https://www.iucnredlist.org/species/41385/115182930

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