Masked Shrew

The masked shrew has an arched brow and a rounded forehead. The upper parts are an ashy to cinnamon color in summer, darker brown in winter. The lower portions of the body are a lighter shade of the dorsal color. The relatively long tail is brown above and a paler buff below, the tip darker. The total length of an average-sized adult is 101 mm (4.0 in) which includes a tail about 41 mm (1.6 in) long. Adults weigh 3-6.5 g (0.11-0.23 oz.). The masked shrew is intermediate in size between the smaller, more slender pygmy shrew and the larger, stockier smoky shrew. The masked shrew has the largest range of any North American shrew and occurs throughout Alaska, Canada, the northern third of the U.S., as well as portions of the Great Basin, Rockies, and the Appalachians. This shrew is found in all terrestrial habitats, natural or disturbed, from the lowest to highest elevations in the Adirondack Park, but is most abundant in cool, moist places within mixed forests, bogs, and swamp edges. The nest, made of plant fibers and 7.6-12.7 cm (3-5 in) in diameter, may be in decaying logs, stumps, the burrows of other mammals, or in the 19 mm (0.75 in) diameter tunnels the masked shrew digs in loose soil. 
Insects comprise 65% of the diet, which also includes centipedes, spiders, earthworms, and carrion. Occasionally, masked shrews kill and consume small animals such as salamanders and nestling birds. Small, soft seeds may form part of the winter diet. A masked shrew requires large quantities of food each day, and one kept in captivity ate 3.3 times its own body weight in a 24 hour period. Merriam (p. 174) described three captive shrews kept in one cage, “....Almost immediately they commenced fighting, and in a few minutes one was slaughtered and eaten by the other two. Before night one of these killed and ate its only surviving companion, and its abdomen was much distended by the meal. Hence in less than 8 hours one of these tiny little beasts had attacked, overcome, and ravenously consumed two of its own species, each as large and heavy itself!” Starvation, brought on by insect populations diminished by autumn cold spells, may explain the dead masked shrews seen along woodland trails at this time of the year.
Category:Shrews
Category:Mammals
Category:Wildlife
Category:American Animals