the nose elongate and pointed. The legs are short and the feet small and
weak. The fur is short but soft and posteriorly directed. The cinereous
shrew, for example, is about 4 inches in length, of which the tail
comprises 1-3/4 inches. The upper parts are dark grayish brown and the
underparts dull gray.
Shrews of the genus _Sorex_ are cosmopolitan in distribution. In North
America they range from the arctic south to Central America. Three
subgenera are recognized by Jackson (1928: 27), all three of which are
represented in the state of Washington. The twelve subspecies present
occupy numerous habitats, and their ranges include almost all of the
state.
Jackson pointed out (1928: 1) that "No other group of American mammals
having a wide distribution, and in many localities an abundance of
individuals, is so little known to the nonprofessional mammalogist as
the long-tailed shrews." In Washington, especially in the coastal area
of western Washington, shrews are widespread and abundant in many
habitats. In some places they are the most common mammal present. In
spite of this their presence is often unsuspected by persons that are
otherwise alert to the animal life around them. This is even more
surprising when one takes into account the facts that long-tailed shrews
are diurnal as well as nocturnal and are less apt to detect the presence
of man than are most other species of mammals.
An important factor making long-tailed shrews inconspicuous is their
small size, and contributing factors include their rapid movements and
dull colors. On several occasions the writer, after seeing a long-tailed
shrew vanish soundlessly under a log or into a patch of dead leaves, was
left wondering if one actually had been seen or if instead his
imagination had conjured up an animal from a dust mote or wind-blown
leaf.
The environment of the long-tailed shrews, except for the water shrews,
is the zone at the very surface of the earth, just beneath the layer of
moss, grass, dead leaves, and decaying vegetation. The removal of the
covering vegetative layer reveals a maze of tiny tunnels, the branchings
and complexities of which are infinite. Tiny traps baited with oats or
meat and set in these runways catch the long-tailed shrews that inhabit
them.
The food of long-tailed shrews is varied. It is principally soft-bodied
insects, insect pupae, and earthworms. At times a considerable quantity
of soft vegetation and some seeds are eaten. Recent studies (Moore,
1940: 1942) have shown that by destroying seeds some shrews may
adversely affect the reforestation of some coniferous trees. Shrews
readily eat meat, and often destroy the small mammals, including other
shrews, taken in the mammal collector's traps.
Hamilton (1940: 485) found that in one species of long-tailed shrew in
the United States individuals rarely lived more than one year. This
seems not to be true of at least some of the species found in
Washington.
Parasites, internal or external, are not commonly found on long-tailed
shrews. They are regularly eaten by owls and snakes, but most
carnivorous mammals, though they readily kill them, rarely eat them.
=Sorex cinereus= Kerr
Cinereous shrew
The cinereous shrew ranges over most of Alaska, Canada and the northern
half of the United States. A number of subspecies have been described,
of which two have been reported from Washington. The cinereous shrew is
of medium size and difficult to distinguish from the dusky and wandering
shrews, especially in eastern Washington, without studying the skulls.
In _cinereus_ the fourth unicuspid tooth is smaller than the third; in
_vagrans_ and _obscurus_ it is larger. The relatively narrow rostrum of
_cinereus_ also serves to separate it from the other two species.
The cinereous shrew seems to be less restricted to the vicinity of
streams and marshes than _Sorex vagrans_, resembling _Sorex obscurus_
and _Sorex trowbridgii_ in this respect. In Washington it seems to be
rare and has not been taken by the writer. Published records for _Sorex
c. cinereus_ indicate that this race is, in Washington, confined to
mountainous areas. The coastal race, _streatori_, seems to be confined
to the humid area.
=Sorex cinereus cinereus= Kerr
_Sorex arcticus cinereus_ Kerr. Anim. Kingd., p. 206, 1792.
_Sorex cinereus cinereus_ Jackson. Jour. Mamm., 6: 56, February 9,
1925.
_Type._--None. Name based on the account of a shrew seen at Fort
Severn, Canada, by J. R. Forster in 1772.
_Racial characters._--Small size and pale color.
_Measurements._--Seven males and 8 females from Indian Point Lake,
British Columbia, average, respectively: total length 99, 95;
length of tail 43.5, 42.2; hind foot 12.7, 12.3.
_Distribution._--Northeastern Washington (Metaline and Loon Lake,
Jackson, 1928: 49) and the Cascades from Whatcom Pass (Jackson,
1928: 55) southward to Conrad Meadows (Jackson, 1928: 49). There
is a specimen in the collection of the California Academy of
Sciences, from Mt. Rainier.
_Remarks._--This is the most wide-ranging subspecies of shrew, being
recorded from Alaska, 10 Canadian provinces and 26 states (Jackson,
1928: 46-50). In the more northern and eastern parts of its range it is
sometimes the commonest shrew.
[Illustration: FIG. 27. Distribution of the cinereous shrew in
Washington. A. _Sorex cinereus cinereus._ B. _Sorex cinereus
streatori._]
=Sorex cinereus streatori= Merriam
_Sorex personatus streatori_ Merriam. N. Amer. Fauna, 10:62,
December 31. 1895.
_Sorex cinereus streatori_ Jackson. Jour. Mamm., 6:56. February 9,
1925.
_Type._--Obtained at Yakutat, Alaska, by C. P. Streator on July 9,
1895; type in the United States National Museum.
_Racial characters._--Larger and darker than _Sorex cinereus
cinereus_.
_Measurements._--Five females from Alta Lake, British Columbia,
average: total length 103; length of tail 45; hind foot 12.5.
_Distribution._--The western part of the northern Cascades
(Glacier, Jackson, 1928: 55) and the Olympic Peninsula (Neah Bay
south to Cedarville, Jackson, 1928: 55).
_Remarks._--This shrew seems to occupy the same range as _Sorex obscurus
setosus_ but is rare where _obscurus_ is common.
=Sorex merriami merriami= Dobson
Merriam shrew
_Sorex merriami_ Dobson. Monogr. Insectivora, pt. 3, fasc. 1, pl.
23, fig. 6, May, 1890.
_Sorex merriami merriami_ Benson and Bond. Jour. Mamm., 20: 348,
August 14, 1939.
_Type._--Obtained on Little Bighorn River, about a mile and a half
above Fort Custer, Crow Indian Reservation, Montana, by Charles E.
Bendire on December 26, 1884; type in United States National
Museum.
_Measurements._--Of type: total length 90; length of tail 35; hind
foot 11.5 (after Jackson, 1928: 80).
_Distribution._--A single specimen of this rare shrew is known
from Washington. Jackson (1928: 81) states that it "was collected
by George G. Cantwell, November 18, 1919, at the entrance to an
old badger digging on top of a 'high bunch grass hill' at Starbuck
(altitude 645 feet), Columbia County, Wash."
_Description._--Similar to _Sorex cinereus_ but upper parts pale grayish
and underparts white.
The Merriam shrew has been recorded from but a few localities in the
western United States. It is one of the rarest of the small mammals
known to occur in North America. All the known specimens have been found
in desert areas.
=Sorex trowbridgii= Baird
Trowbridge shrew
_Description._--The Trowbridge shrew closely resembles the cinereous
shrew in body form but possesses a longer tail. The head and body of
adults measure about 2-1/4 inches and the tail about 2 inches. The
Trowbridge shrew may be separated from all other small shrews that
occur in Washington by its dark bluish upper parts and bluish or slaty
underparts. The tail is distinctly bicolor.
Trowbridge shrews occur from southern British Columbia south to central
California. Their distribution, to the south, is more extensive than
that of many members of the Pacific Coastal Fauna. They are forest
animals, ranging widely over the dry ground beneath the fir forest,
where they are usually the only shrews present. They are abundant in
ravines and in some swampy woods when other shrews are absent, but they
avoid open meadows or marshes. Vertically, they occur from the humid
division of the Transition Life-zone to the Hudsonian Life-zone.
These little shrews do not live well in captivity and I have learned
relatively little concerning their habits from live specimens. They
seem to be slower-moving and less aggressive than the wandering shrew.
Population studies showed that the Trowbridge shrew is unable to
compete with the wandering shrew in ravine habitats (Dalquest, 1941A:
173). The principal food of the Trowbridge shrew includes soft-bodied
insects and insect pupae.
[Illustration: FIG. 28. Distribution of the Merriam and Trowbridge
shrews in Washington. A. _Sorex merriami merriami._ B. _Sorex
trowbridgii trowbridgii._ C. _Sorex trowbridgii destructioni._]
Moore (1942) has shown that shrews eat the seeds of the Douglas fir
and may be a serious check on the reproduction of this important tree.
The Trowbridge shrew is the most abundant shrew in the fir forests and
probably constitutes the principal shrew that might be classed as a
pest.
A specimen containing 4 embryos was taken near Shelton, Mason County,
on April 23, 1937. Males with enlarged, greenish testes were taken in
April of 1938, 1939 and 1940. Specimens obtained in other months showed
no indications of breeding.
=Sorex trowbridgii trowbridgii= Baird
_Sorex trowbridgii_ Baird, Rept. Pacific R. R. Survey, 8 (pt.
1):13, 1857.
_Type._--Two cotypes were obtained at Astoria, Clatsop County,
Oregon. The skin of one (the lectotype) was entered in the U. S.
National Museum catalogue in July, 1855, and the skull in January,
1857. The other was obtained by J. Wayne on July 10, 1855.
_Racial characters._--Small size and narrow skull.
_Measurements._--The average measurements of 38 adults from King
County, Washington, are: total length 115.3; length of tail 54.4;
hind foot 13.4.
_Distribution._--Forested areas from the Pacific Coast eastward
through the Cascades to Stehekin (Jackson, 1928: 96), 2 mi. S.
Blewitt Pass (Jackson, 1928: 96) and Satus Pass (M.V.Z.).
=Sorex trowbridgii destructioni= Scheffer and Dalquest
_Sorex trowbridgii destructioni_ Scheffer and Dalquest, Jour.
Mamm., 23:334, August 13, 1942.
_Type._--Obtained on Destruction Island, Jefferson County,
Washington, by V. B. Scheffer on April 22, 1941; type in United
States National Museum.
_Racial characters._--Large size and wide skull.
_Measurements._--Thirty topotypes average: total length 122.5;
length of tail 56.7; hind foot 14.3; weight 7.5 grams.
_Distribution._--Known only from Destruction Island, 35 acres in
area, lying 4 miles off the Washington Coast.
=Sorex vagrans= Baird
Wandering shrew
_Description._--This species closely resembles the cinereous shrew in
body form. Its head and body measure about 2-1/4 inches; the tail
slightly less than 2 inches. In summer the upper parts are reddish brown
and the underparts gray tinged with brownish. In winter the upper parts
are more dusky.
Several races of the wandering shrew range over western North America
from southwestern British Columbia south to southern Mexico. Two races
occur in the state of Washington.
Marshy areas and damp places are the habitat of the wandering shrew.
Cattail and tule marshes, sphagnum bogs, and meadows are favored.
They frequent streams through forests but rarely are taken in places
away from water. On some of the San Juan Islands, wandering shrews
were found along the beaches where they were feeding on the amphipods
that live in the dead seaweed and litter at the high tide line. In a
favorable habitat, wandering shrews may be the most abundant mammal
present. Specimens are occasionally taken in 90 per cent or more of a
mammal collector's traps.
The preference of the wandering shrew for damp areas makes it more
or less independent of life-zones, for marshy areas, whether in
Transition, Canadian, or Upper Sonoran life-zones, present comparable
ecological conditions.
Broadbrooks (1939: 65) found that captives taken at Seattle ate rolled
oats, apple, fresh or cooked meat, sow bugs, centipedes, earthworms,
frogs (_Hyla regilla_), a salamander (_Plethodon vehiculum_), and
small, black slugs (_Arean arean_). Wandering shrews proved incapable
of destroying snails (_Helisoma occidentalis_) and large slugs. The
captive shrews kept by Broadbrooks ate an average of 1.3 times their
own weight in food each day.
[Illustration: FIG. 29. Distribution of the wandering shrew in
Washington. A. _Sorex vagrans vagrans._ B. _Sorex vagrans monticola._]
The wandering shrew changes from winter to summer pelage in a few days,
seemingly in the second week of October (Dalquest, 1944: 147). The
spring molt occurs rapidly but perhaps at a less regular date. Rarely a
midsummer molt occurs.
The earliest evidence of breeding in a wandering shrew was discovered
on January 27, 1937. Most adult females taken in February, March, April
and May were pregnant. Embryos were less often found in summer and
fall, but one pregnant female was taken in November. Embryos varied in
number from 3 to 8 with an average of six.
=Sorex vagrans vagrans= Baird
_Sorex vagrans_ Baird, Rept. Pacific R. R. Survey, 8 (pt. 1):15,
1857.
_Sorex suckleyi_ Baird, Rept. Pacific R. R. Survey, 8 (pt. 1):18,
1857 (type from Steilacoom Pierce County, Washington).
_Type._--Obtained at Willapa Bay [Shoalwater Bay], Pacific County,
Washington, by J. G. Cooper; entered in U. S. Nat. Mus. catalogue
on October 23, 1856.
_Racial characters._--Dark color.
_Measurements._--Twenty-five males and 25 females from Seattle,
King County, average, respectively: total length 110.5, 107;
length of tail 44.6, 45; hind foot 12.4, 12.4.
_Distribution._--This is the common marsh shrew of western
Washington and occurs from the Pacific Ocean east to the Cascades
at Lake Keechelus (W.S.M.) and 15 mi. NW White Salmon (Jackson,
1928: 106).
=Sorex vagrans monticola= Merriam
_Sorex monticolus_ Merriam, N. Amer. Fauna, 3:43, September 11,
1896.
_Sorex vagrans monticola_ Merriam, N. Amer. Fauna, 10:69, December
31, 1895.
_Type._--Obtained on San Francisco Mountain, 1150 ft. altitude,
Coconino County, Arizona, by C. H. Merriam and V. Bailey on August
28, 1889; type in United States National Museum.
_Racial characters._--Pale color.
_Measurements._--Five males and 5 females from Selah, Yakima
County, average, respectively: total length 100, 98.4; length of
tail 40.6, 39.2; hind foot 12.2, 12.
_Distribution._--Eastern Washington. The range of this shrew
extends west to Bauerman Ridge (Jackson, 1928: 113), Merritt
(W.W.D.) and Maryhill (M.V.Z.).
_Remarks._--A series of shrews from Moses Lake, Grant County,
differs from _monticola_ in larger size and darker color. They
agree rather closely with _Sorex r. amoenus_ from California and
Nevada. Because they are isolated from that subspecies it seems
best to consider them a microgeographic race referable to
_monticola_.
=Sorex obscurus= Merriam
Dusky shrew
_Description._--The dusky shrew is similar in form of body to the
cinereous shrew. The length of head and body is about 2-1/4 inches. The
tail is about 2-1/2 inches. The upper parts are rusty or reddish brown.
The underparts are brownish gray. The dusky shrew differs from the
wandering shrew in possessing a slightly longer body and longer tail,
but in eastern Washington the two species are almost indistinguishable.
Dusky shrews range from northern Alaska to southern New Mexico, and from
the Rocky Mountains to the Pacific Ocean. Thirteen subspecies are
recognized by Jackson (1928: 115), of which two occur in Washington.
Records of the dusky shrew are not available from the arid subdivision
of the Transition or the Upper Sonoran life-zones. It occurs sparingly
in the humid subdivision of the Transition and is common in the Canadian
and Hudsonian life-zones.
The habitat of the dusky shrew is varied. Near Seattle, King County,
several specimens were trapped in marshes where _Sorex vagrans_ was
abundant. Near Stevens Pass, King County, two were taken in a marsh; two
others were trapped in a dry, coniferous forest; one was taken in a
small bed of heather on a barren mountain top; and another was found
dead in a pan of pancake batter in camp. Two specimens were trapped
along a small stream at Dewey Lake, Mt. Rainier, Yakima County. Four
specimens were caught in traps set in a talus slope on a dry hillside at
the North Fork of the Quinault River, Jefferson County. Three others
were trapped in dense, rain-forest thickets along the ocean at La Push,
Jefferson County. These records indicate that the dusky shrew has a
wider environmental range than other Washington shrews. Despite this
wide range of tolerance the dusky shrew is common only locally, except
in the Hudsonian Life-zone.
Little is known of the habits of dusky shrews but they seem to be as
diurnal as they are nocturnal. At Wolf Bar, North Fork of the Quinault
River, Jefferson County, a dusky shrew was seen on the packed-earth
floor of an old trapper's cabin. A hat was carefully dropped over the
live animal but, when the hat was lifted, the shrew was found dead. In
an old cabin at Stevens Pass, King County, a dusky shrew was found dead
one morning in a pan of flapjack batter prepared the evening before. As
this pan was on a table about three feet from the floor, the shrew must
have climbed to the table by way of the rough cabin wall, but how the
animal managed to scale the side of the pan is a mystery.
Slipp (1942: 211) discovered the nest of a dusky shrew between Round
Pass and Lake George, 4200 feet elevation, in Mt. Rainier National Park,
on July 25, 1937. The nest was in a rotten fir log 20 inches in
diameter. The nest, a ball of dry grass the size of a man's fist, had no
central cavity or passages, the occupants "merely pushed through
wherever they wished." Seven young shrews were found in and near the
nest. Though the eyes of the young were still closed, they were able to
creep about and squeal.
A specimen obtained 5 miles west-southwest of Guler, Skamania County,
contained 4 embryos on July 10, 1939.
[Illustration: FIG. 30. Distribution of the dusky shrew in Washington.
A. _Sorex obscurus obscurus._ B. _Sorex obscurus setosus._]
=Sorex obscurus obscurus= Merriam
_Sorex vagrans similis_ Merriam, N. Amer. Fauna, 5: 34, July 30,
1891 (not of Hensel, 1855).
_Sorex obscurus_ Merriam, N. Amer. Fauna, 10: 72, December 31,
1895 (substitute for _similis_ Merriam).
_Type._--Obtained on Timber Creek, 8,200 ft., Lemhi Mountains,
Lemhi County, Idaho, by V. Bailey and B. H. Dutcher on August 26,
1890; type in United States National Museum.
_Racial characters._--Tail relatively short, color pale.
_Measurements._--Thirteen males and 10 females from Indian-point
Lake, British Columbia, average, respectively: total length 105,
107; length of tail 45, 46; hind foot 13.3, 13.3.
_Distribution._--Northeastern Washington west, according to
Jackson (1928: 122), to Pasayten River, Stehekin and Wenatchee.
Because specimens from Tye, King County, and Mt. Stuart, Easton
and Lake Keechelus are clearly referable to _S. o. setosus_, the
specimens recorded by Jackson (1928: 122), from Easton and Signal
Peak, are mapped in the range of _setosus_.
=Sorex obscurus setosus= Elliot
_Sorex setosus_ Elliot, Field Columb. Mus. Publ. 32. zoöl. ser.,
1:274. March, 1899.
_Sorex obscurus setosus_ Jackson, Proc. Biol. Soc. Washington.
31:127. November 29, 1918.
_Sorex obscurus bairdi_ Jackson, N. Amer. Fauna, 51:140. July 24,
1928.
_Type._--Obtained at Happy Lake, Clallam County, Washington, by D.
G. Elliot on August 18, 1898; type in Field Museum of Natural
History.
_Racial characters._--Tail long, color dark.
_Measurements._--Twelve males and 17 females from southwestern
Washington average, respectively: total length 118, 119; length of
tail 53, 53; hind foot 13.8, 13.7; weight 6.6, 5.2 grams.
_Distribution._--Western Washington, east through the Cascades to
Barron (Jackson, 1928: 137), Cascade River (Jackson 1928: 137) and
Satus Pass (W. W. D.).
=Sorex palustris navigator= (Baird)
Mountain water shrew
[Illustration: FIG. 31. Distribution of the mountain water shrew.
_Sorex palustris navigator_, in Washington.]
_Neosorex navigator_ Baird, Rept. Pacific R. R. Survey, 8 (pt. I):
11, 1857.
_Sorex (Neosorex) palustris navigator_ Merriam, N. Amer. Fauna,
10:92, December 31, 1895.
_Sorex palustris navigator_ Stephens, California Mammals, p. 254,
June, 1906.
_Type._--Obtained at head of Yakima River, Kittitas County,
Washington, by J. G. Cooper on August 31, 1853; type in United
States National Museum.
_Measurements._--Two males and 4 females from Washington average,
respectively: total length 150, 150; length of tail 70, 74; hind
foot 18.5, 20; weight?, 11.0 grams.
_Distribution._--Mountainous areas of entire state, including the
Olympic Mountains, from Elwah (Jackson, 1928: 188) south to
Quinault River (Jackson, 1928: 189); the Cascades from Tomyhoi
Lake (W. W. D.) south to 15 mi. N. Carson (Jackson, 1928: 189);
northeastern Washington from Shovel Creek (W. W. D.) south to
Gifford (Jackson, 1928: 189); the Blue Mountains at Godman Springs
(M. V. Z.) and Hompeg Falls (M. V. Z.).
_Description._--In general form of body the mountain water shrew
resembles the cinereous shrew but is perhaps more stocky. It is a large
shrew, nearly as large as a house mouse. The head and body measure about
3 inches; the tail also is about 3 inches long. The fur is exceedingly
soft. The upper parts are blackish in color, lightly frosted with paler
hairs. The underparts, from throat to vent, are whitish tinged with gray
or brown. The stiff, curved fringe of bristles on the outer part of the
hind foot serves as an aid in swimming.
Mountain water shrews range over much of Canada and in mountainous areas
of the western United States extend south to Arizona. The subspecies
found in Washington ranges over all of the western United States.
The mountain water shrew is primarily a mammal of the Hudsonian and
Canadian life-zones. It sometimes descends to the Transition Life-zone
along clear, cold streams where conditions are similar to those in the
Canadian Life-zone.
The favored habitats of the mountain water shrew are the clear, cold
streams of the alpine cirques and gushing streams on the mountain sides.
In the pools and waterfalls, and among the rocks and mosses that border
them, the larvae of aquatic insects, upon which the mountain water shrew
feeds, are abundant. Svihla (1934: 45) observed that the fur of a
swimming water shrew gathered air bubbles and "it had difficulty in
forcing its way down to the bottom [of an aquarium]. On reaching the
bottom it literally stood on its long flexible nose which was thrust
into the sand and debris, searching for food, its feet kicking rapidly
in order to maintain this position. A change in direction was brought
about by a twist of the body. To come to the surface again it merely
stopped kicking and immediately rose like a cork." The buoyancy of the
water shrew allows it to float in the water, like a duck. Jackson (1928:
9) observed a water shrew run across the surface of a small pool. Near
Stevens Pass a water shrew dashed from under a stone and ran, did not
swim, across the surface of a small, deep pool to escape in a burrow on
the other side. According to Jackson, an air bubble held in each foot
supports the shrew on the surface of the water. A mountain water shrew
observed at Shovel Creek, Ferry County, was as agile on land as any
other species of shrew. In summary, water shrews are able to swim, dive,
float like a duck, and walk on the surface of the water as well as walk
on land.