Field Guide/Mammals/Masked Shrew

Masked Shrew sorex cinereus MaskedShrew23.jpg thumb MaskedShrew23 Masked Shrew Soricidae The masked shrew usually weighs between .08-1.4 ounces (2.5-4.0g) and is approximately 3.9 inches (10cm) in length. Average length of the tail is 1.5 inches (3.9cm), comprising over 40% its the total length.Leel W. 2010 Masked Shrew University of Michigan Museum of Zoology http://animaldiversity.ummz.umich.edu/accounts/sorex_cinereus/ October 10, 2012 The fur along the back is brown, while underside fur is white. The coat tends to be darker overall in winter. The tail is brown above and pale underneath, with a blackish tip.last1Whitakerl J.O. 2004 Sorex Cinereus Mammalian Species 743 1–9. http://www.science.smith.edu/msi/pdf/743_Sorex_cinereus.pdf October 10, 2012 The masked shrew can easily be mistaken with the pygmy shrew (Sorex hoyi)which is slightly smaller. Although similar in size, their coloration is different where the masked shrew is darker in color. The masked shrew is the most widely distributed shrew found in North America. They 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.last1Whitakerl J.O. 2004 Sorex Cinereus Mammalian Species 743 1–9. http://www.science.smith.edu/msi/pdf/743_Sorex_cinereus.pdf October 10, 2012 The masked shrew typically live in 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 where water is easily accessible.Leel W. 2010 Masked Shrew University of Michigan Museum of Zoology http://animaldiversity.ummz.umich.edu/accounts/sorex_cinereus/ October 10, 2012 The Masked shrew is omnivorous although they are on the carnivorous side as they primarily eat a variety of insects primarily consisting of ants.They also commonly consume insect larvae and caterpillars. Masked shrews are primarily nocturnal and are solitary. They can run fast to protect themselves from predation.Leel W. 2010 Masked Shrew University of Michigan Museum of Zoology http://animaldiversity.ummz.umich.edu/accounts/sorex_cinereus/ October 10, 2012 Young become sexually active at 2 months although few females have their first litter until the spring after their birth. Their average litter size is around 6.5 neonates at birth the young can exhibit movements but cannot crawl, see, or hear. they are weaned and grown enough to leave the nest at 27 days of age.Hazardl E. 1982 The Masked Shrew Mammals in Minnesota 21–27 The masked shrew typically lives 1-2 years.Hazardl E. 1982 The Masked Shrew Mammals in Minnesota 21–27 All shrews (including the masked shrew) have a very high metabolic rate which includes and very fast heart beat. Some shrews have had their heartbeats measured at 1200 beats per minute. To maintain themselves they must eat their weight in food every day. This is accomplished by eating every few minutes. With a heart beating so fast the animals are easily startled and with deadly consequences, as they have been known to die of fright after a loud burst of thunder.