Fauna Series No. 3

Fauna of the National Parks — No. 3 Birds and Mammals of Mount McKinley National Park

Mammals

DESCRIPTIONS OF MAMMAL SPECIES

MASKED SHREW
Sorex personatus personatus [I. GOEFFROY]

GENERAL APPEARANCE.—A very small, active mammal with a sharp pointed nose and small beady eyes. The ears are nearly hidden in the brownish fur of the animal. The tail is well covered with hairs, yellowish white beneath and brown above; the feet are small and delicate. Total length, 4 inches; tail, 1.6 inches; hind foot, 0.5 inch.

IDENTIFICATION.—In contrast to the rather uniform coloration of the dusky shrew, the back of the masked shrew is sepia brown sprinkled with lighter and darker hairs giving the appearance of the animal a "salt and pepper" effect.

DISTRIBUTION.—It is found in the Boreal and Transition Zones of North America from New England to Alaska. On October 8, 1907, shrews were abundant in Sheldon's winter cabin on the main Toklat River.

We found the shrews to be scarce in 1926, and in 1932 I found them to be scarcer still. Some years they are abundant but at other times they are not at all plentiful.

HABITS.—According to Sheldon (1930, p. 169), the shrews were especially cannibalistic, eating mice or shrews that had been caught in the traps each night.

TUNDRA SHREW
Sorex tundrensis [MERRIAM]

GENERAL APPEARANCE.—The tundra shrew is similar to the masked shrew but the tail is shorter. This shrew is large in size. Total length, 4.3 inches; tail, 1.3 inches; hind foot, 0.5 inch.

IDENTIFICATION.—In many instances cranial characters are those relied upon by the specialist to separate different geographic forms or species of shrews. Such characters are not available to the field student; therefore, specimens must be examined in detail later in the laboratory. This shrew is larger in size as compared with other shrews in the McKinley region.

DISTRIBUTION.—It is found in the tundra belt in the region above and east of Norton Sound, Alaska. Sheldon reports this species taken along with other shrews in the Toklat region. We did not encounter it either in 1926 or in 1932 and are inclined to believe that it is rare in McKinley Park.

HABITS.—So far as is known, the habits of this species in McKinley Park are similar to those of personatus.

DUSKY SHREW
Sorex obscurus obscurus [MERRIAM]

GENERAL APPEARANCE.—The upper surface of the animal is rich brown. The under parts are ashy. The tail is bicolored, that is, whitish below and brown like the back above. It is large in size and the tail is relatively long. Total length, 4.4 inches; tail, 1.8 inches; hind foot, 0.5 inch.

IDENTIFICATION.—In McKinley Park this species may be distinguished from personatus by the uniform color of the upper parts and by the slightly longer tail.

DISTRIBUTION.—It is found in the Boreal Zone of the higher mountain ranges of western North America from Mount Whitney, in California, to Mount McKinley, in Alaska.

In an old cabin at Copper Mountain on July 12, 1926, I found the dried-up remains of a dusky shrew in an old dishpan. It was evident that the animal had fallen into the pan from which it had been unable to escape. This specimen was sent to Washington and through the kindness of Dr. Hartley H. T. Jackson of the United States Biological Survey it was identified by him.

HABITS.—Mr. and Mrs. John E. Anderson reported the capture of this shrew in their garden at Wonder Lake.

It is probably the commonest species of shrew in the park.

COOK INLET PIGMY SHREW
Microsorex hoyi eximius [OSGOOD]

GENERAL APPEARANCE.—It is the smallest of the shrews. In color it is dark brown above and buffy or ashy on the throat, breast, and belly. The tail is bicolored. The sexes are alike in color and size. Total length, 3.3 inches; tail, 1.3 inches; hind foot, 0.4 inch.

IDENTIFICATION—The small size of this shrew will identify it among the adults of other species found in the region.

DISTRIBUTION.—Microsorex is found chiefly in eastern North America but this geographic race is found on the Kenai Peninsula and in the Mount McKinley region. Charles Sheldon collected specimens on the upper Toklat River along the base of the Alaska Range in 1906-8. We searched for this shrew, but did not find it either in 1926 or in 1932, and we consider it a rare species in Mount McKinley National Park.

HABITS.—Little is known of the habits of this species other than that which applies to shrews in general in the park.

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Last Modified: Thurs, Oct 4 2001 10:00:00 pm PDT
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