Kansas Mammal Atlas

Distribution:
Sorex cinereus, is the most widely distributed shrew found in North American. Common shrews occur throughout the northern United States, most of Canada, and Alaska. They do not occur on Vancouver Island, the Queen Charlotte Islands, in tundra habitats, arctic islands, or in extreme northern Quebec. (Nagorsen, 1996; van Zyll de Jong, 1983). Common shrews occupy a diversity of habitats, most common are open and closed forests, meadows, river banks, lake shores, and willow thickets. Habitat suitability depends on the availability of water and the highest population densities can be found in moist environments. Common shrews also do well in disturbed habitats such as those disturbed by fire or logging. The average home range is 0.6 hectares (Nagorsen, 1996; Pagels, et al. 1994)).

(, Museum Voucher) (, Observation) (, Literature Record)
Open icons are questionable records; Click on a marker to view details.

• Occurrence Summary:  
• 55 Total Records 
• 55 Museum Vouchers 
• 0 Other Observations 

Some county occurrences indicated below may be too imprecise to map above.
County Breakdown: County Name (# occurrences):
Jewell (16); Marshall (2); Mitchell (3); Nemaha (1); Osborne (1); Ottawa (4); Phillips (3); Republic (14); Riley (1); Rooks (1); Smith (8); Washington (1);

Natural History:
Masked Shrews are most active after dark, when 85 per cent of activity occurs. They are especially active between 01:00 and 02:00, when there has been a rainfall, or on very dark nights. Their primary activity is hunting. Common shrews hunt primarily on the ground but may also climb into low vegetation and shrubs. They run quickly, can jump to 10-15 cm high, and dig in loose substrate (Nagorsen, 1996; van Zyll de Jong, 1983).
Masked shrews probably do not live much past 1 to 2 years old, most probably die before reaching adulthood, they avoid being preyed upon by staying under cover and being active mostly at night, they are rarely seen.
Masked Shrews are most active after dark, when 85 per cent of activity occurs. They are especially active between 01:00 and 02:00, when there has been a rainfall, or on very dark nights. Their primary activity is hunting. Common shrews hunt primarily on the ground but may also climb into low vegetation and shrubs. They run quickly, can jump to 10-15 cm high, and dig in loose substrate (Nagorsen, 1996; van Zyll de Jong, 1983).
Because Sorex cinereus inhabits a wide range there is great geographic variation in diet. Ants represent 50% of the food source for common shrews in Michigan, whereas insect larvae are the dominant prey item in New Brunswick. Kelp flies and marine amphipods are major dietary items in Nova Scotia. They are also important predators of forest insect pests such as Jack Pine Budworms and Larch Sawflies. In general, common shrews consume a variety of invertebrates including insect larvae, ants, beetles, crickets, grasshoppers, spiders, harvestmen, centipedes, slugs, snails. Seeds and fungi are also consumed (Nagorsen, 1996).
Masked shrews avoid being preyed upon by staying under cover and being active mostly at night, they are rarely seen.
The breeding season for Sorex cinereus occurs from April to October in eastern North America but may extend into November if food is plentiful. Length of gestation is unknown. The average number of embryo produced by various populations ranges from five to eight across North America, with at least two litters produced by a female in a breeding season. Both males and females may breed in their first summer but this is not typical (Nagorsen, 1996).Young are cared for and nursed by their mother in her nest until they reach about 20 days old.

Occurrence Activity:

Remarks:
Little is known of communication in masked shrews. They have an excellent sense of smell and can see fairly well. They use their sensitive whiskers to find their way around and detect prey. Masked shrews also probably squeak and hiss as a way of communicating.

Bibliography:

Account Last Updated:
7/13/2017 10:48:54 AM