SHREWS 47 



Shrews. Genus Sorex- 



Field characters. — Size varying, but always less than half that of House Mouse. Head 

 and body not over 3 inches (75 mm.) long, tail 2 inches (50 mm.) or less. Snout long 

 and pointed (pi. 20) ; eyes and ears inconspicuous; pelage short, dense and smooth- 

 appearing. Forefeet like hind feet, not specialized for digging. Coloration uniform, 

 brown above (varying in tone according to the species), lighter, sometimes whitish, 

 on under surface. 



Occurrence. — Common from upper margin of Upper Sonoran Zone up to upper edge 

 of Hudsonian Zone; recorded from Dudley, on Smith Creek (east of Coulterville), east- 

 ward to vicinity of Mono Lake.2 (See fig. 6.) Live chiefly in damp situations along 

 stream banks or in meadows, but sometimes found in protected situations at considerable 

 distances from water. 



Shrews are present in the Yosemite region in large numbers, yet because 

 of their small size and secretive habits they are much less well known than 

 are the majority of other small mammals, such as meadow mice. The 

 shrews leave little or no visible evidence of their activity, and it takes much 



2 Five species of true shrews (Genus Sorex) occur in the Yosemite region. The 

 general appearance and the habits are much the same in all of these, though but little 

 information other than that gained by trapping is available regarding their life histories. 

 The species, their ranges, and their chief characters are as foUows: 



Dusky Shrew, Sorex obscurus ohscurus Merriam, a wide-ranging species found both 

 in the Eocky Mountains and in the Sierra Nevada south to Tulare County, is common 

 in the Canadian and Hudsonian zones of the Yosemite region from Mono Meadow (near 

 Glacier Point) and from East Fork of Indian Canon eastwai'd to Warren Fork of Leevin- 

 ing Creek and to Williams Butte. Extreme altitudes of capture were 6900 and 10,800 

 feet. It lives not only along streams and in marshy places but also about logs on the 

 forest floor. Total length about 4 to 4^/^ inches, tail 1% inches, hind foot % inch 

 (12.2-13.0 mm.); coloration dull sepia brown above, ashy on under surface. (See 

 pi. 20c.) 



Adorned Shrew, Sorex ornatus Merriam, is found in mountainous parts of southern 

 California and on the lower west slope of the Sierra Nevada, from the Mexican boundary 

 north to the Yosemite region. Locally it is common at El Portal, and one individual 

 was taken at Dudley, 6 miles east of Coulterville. Lives both along streams and on 

 hillsides covered with live oaks and brush. Total length 4 inches, tail 1% inches, hind 

 foot about V^ inch (12-13.5 mm.). Coloration dull brown above, whitish beneath. 



Yosemite Shrew, Sorex montereyensis marijyosae Grinnell, lives in the Transition 

 Zone and lower part of the Canadian Zone on the west flank of the Sierra Nevada. It 

 was found from Sweetwater Creek and Merced Grove Big Trees eastward to East Fork 

 of Indian Canon and to Merced Lake; it is the only shrew recorded for the floor of 

 Yosemite Valley. Extreme altitudes of occurrence, 3800 and 7500 feet. It inhabits 

 almost exclusively damp places near streams. Total length 4% to 5 inches, tail 2 inches, 

 hind foot somewhat more than % inch (14-15 mm.). Largest local shrew of the genus 

 Sorex. Coloration mixed hair brown and drab gray above, drab gray below with a 

 silvery sheen. (See pi. 20b.) 



Sierra Nevada Shrew, Sorex vagrans amoenus Merriarn, of wide distribution along 

 the northern Sierra Nevada, was found by us only at Williams Butte and Mono Lake 

 Post Office. Lives near streams or in meadows. Total length about 4 inches, tail usually 

 less than 1^2 inches, hind foot about % inch (11.5-13 mm.). Pelage sooty brown, 

 grizzled with lighter brown above; under surface buflfy white. The relatively short tail 

 as compared with the tail of other shrews is a fairly good distinguishing feature. 



Lyell Shrew, Sorex lyelli Merriam, is a rare species, known at present only from 

 the general neighborhood of the peak for which it is named. Single specimens were 

 taken by our party at Vogelsang Lake, 10,350 feet altitude, September 1, 1915, head of 

 Lyell Canon (= slopes of Mount Lyell) at 9800 feet, July 24, 1915, and near Williams 

 Butte, at 6900 feet, September 20, 1915. Inhabits moist situations, near streams, in 

 grass or under willows. Total length about 4 inches, tail 1% inches or more, hind foot 

 less than y^ inch (11-12 mm.). Light hair brown above, paler on under surface. 



