Dalquest (1948:139) it is commonest at high altitudes in western
Washington. In the Hudsonian Life-zone where shrew habitat is more
restricted and marginal than it is at lower altitudes in the humid
part of Washington, _setosus_ might be expected to compete with _S. v.
vagrans_ and to supplant it. Records of occurrence in the Olympic
Mountains suggest a degree of such separation there.
_Specimens examined._--Total number, 135.
BRITISH COLUMBIA: Lund, Malaspina Inlet, 4 BS; Gibson's Landing, 10
BS; Port Moody, 19 BS; Langley, 2 BS; Chilliwack, 1 BS; Manning Park, 2
PMBC.
WASHINGTON: _Whatcom Co._: Mt. Baker, 6 WSC; Barron, 1 BS. _Chelan
Co._: Clovay Pass, 1 WSC; Stehekin, 6 (4 WSC, 2 BS); Cascade Tunnel, 1
WSC. _King Co._: Scenic, 1 WSC. _Kittitas Co._: Lake Kachess, 1 WSC;
Easton, 10 BS. _Clallam Co._: 8 mi. W Sekin River, 1 WSC; mouth of
Sekin River, 1 WSC; Clallam Bay, 1 CMNH; 7 mi. W Port Angeles, 1 WSC;
Ozette Lake, 1 CMNH; 12 mi. S Port Angeles, 4 WSC; Forks, 1 CMNH; Deer
Lake, 7 CMNH; Hoh Lake, 1 CMNH; Bogachiel Peak, 1 CMNH; Sol Duc Hot
Springs, 3 CMNH; Sol Duc Park, 1 CMNH; Canyon Creek, 1 WSC; Sol Duc
Divide, 2 WSC; Cat Creek, 2 WSC. _Jefferson Co._: Jackson Ranger
Station, 1 CMNH; Mt. Kimta, 2 CMNH; Reflection Lake, 6 CMNH; Blue
Glacier, 3 CMNH. _Gray's Harbor Co._: Westport, 1 WSC. _Pierce Co._:
Fort Lewis, 1 FC; Mt. Rainier, 19 (16 BS, 3 WSC). _Pacific Co._:
Tokeland, 2 BS. _Yakima Co._: Gotchen Creek, 3 WSC; Mt. Adams, 1 WSC.
_Skamania Co._: Mt. St. Helens, 1.
OREGON: _Hood River Co._: 2 mi. W Parkdale, 2 BS.
_Marginal Records._--BRITISH COLUMBIA: Rivers Inlet (Anderson,
1947:20); _Agassiz_ (Jackson, 1928:136); Chilliwack Lake. WASHINGTON:
Barron; Lyman Lake (Jackson, 1928:137); Mt. Stuart (Dalquest,
1948:141); Mt. Adams. OREGON: _2 mi. W Parkdale_. WASHINGTON: Ilwaco
(Jackson, 1928:137); Lund, Malaspina Inlet.
=Sorex vagrans longicauda= Merriam
_Sorex obscurus longicauda_ Merriam, N. Amer. Fauna, 10:74,
December 31, 1895.
_Type._--Adult male, skin and skull; No. 74711, U. S. Biol. Surv.
Coll.; obtained on September 9, 1895 by C. P. Streator, from Wrangell,
Alaska.
_Range._--The British Columbian and Alaskan coasts from Rivers Inlet
north to near Juneau and also certain islands including Etolin,
Gravina, Revillagigedo, Sergeif, and Wrangell.
_Diagnosis._--Size medium for the species, tail relatively long;
average and extreme measurements of 17 specimens from the type
locality are: total length, 128.4 (122-138); tail, 57.8 (53-66); hind
foot, 15.1 (14-16). Color dark in summer and winter.
_Comparisons._--For comparison with _S. v. setosus_ see account of
that subspecies. Larger and darker than _S. v. obscurus_ with which it
intergrades east of the humid coastal region; larger and darker than
_S. v. alascensis_ with which it intergrades in the Lynn Canal area;
larger and darker than _S. v. calvertensis_ which occurs on Calvert
Island and Banks Island, British Columbia; differs from _S. v.
insularis_ of Smythe, Townsend, and Reginald islands in larger size
and blackish rather than brown winter pelage; larger and relatively
longer-tailed than _S. v. elassodon_ which occurs on most of the
islands west of the range of _longicauda_; larger and relatively
longer-tailed than _S. v. isolatus_.
_Specimens examined._--Total number, 151.
ALASKA: Wrangell, 54 BS; 8 AMNH; Crittenden Creek, 1 BS; Ketchikan, 2
BS; Loring, 11 BS.
BRITISH COLUMBIA: Port Simpson, 25 BS; Inverness, 15 BS; head of
Rivers Inlet, 35 BS.
_Marginal Records._--BRITISH COLUMBIA: Great Glacier, Stikine River
(Jackson, 1928:133). ALASKA: Burroughs Bay (_ibid._). BRITISH
COLUMBIA: Bella Coola region (Anderson, 1947:19); head of Rivers
Inlet; Spider Island (Cowan, 1941:101); Goose Island (Cowan, 1941:99);
Princess Royal Island (Cowan, 1941:98); Pitt Island (_ibid._);
Metlakatla (Jackson, 1928:133); Port Simpson. ALASKA: Gravina Island
(_ibid._); Helm Bay (_ibid._); Etolin Island (_ibid._); Sergeif
Island, mouth of Stikine River (_ibid._); Sumdum Village (_ibid._);
Port Snettisham (_ibid._).
=Sorex vagrans mixtus= Hall
_Sorex obscurus mixtus_ Hall, American Nat., 72:462, September
10, 1938.
_Type._--Adult male, skin and skull; No. 70376, Mus. Vert. Zool.;
obtained on May 4, 1936, by R. A. Cumming, from Vanada, Texada Island,
Georgia Strait, British Columbia.
_Range._--Known only from the type locality.
_Diagnosis._--Size medium; average and extreme measurements of 5
specimens from the type locality are: total length, 111 (108-117);
tail, 48 (44-49); hind foot, 12 (12-13) (Hall, 1938:463).
_Comparisons._--Color much as in _S. v. setosus_ or _S. v. isolatus_;
palate longer than that of _isolatus_ or _setosus_; hind foot shorter
than either; smaller than _S. v. longicauda_.
=Sorex vagrans isolatus= Jackson
_Sorex obscurus isolatus_ Jackson, Jour. Washington Acad.
Sci., 12:263, June 14, 1922.
_Type._--Adult male, skin and skull; No. 177719, U. S. Biol. Surv.
Coll.; obtained on May 21, 1911, by Alexander Wetmore from mouth of
Millstone Creek, Nanaimo, Vancouver Island, British Columbia.
_Range._--Vancouver Island.
_Diagnosis._--Size medium; measurements of two from the type locality
are: total length, 113, 118; tail, 48, 49; hind foot, 14, 14. Dark in
summer and winter, underparts brownish.
_Comparisons._--Smaller than _S. v. setosus_ but color much the same;
resembles _S. v. obscurus_ in size and cranial characters but darker
in all pelages; similar in color to _S. v. vancouverensis_ with which
_isolatus_ is sympatric but with longer tail, longer hind feet,
broader rostrum and larger teeth. For comparison with _S. v. mixtus_
see account of that subspecies.
_Remarks._--_S. v. isolatus_ and _S. v. vancouverensis_ seemingly
approach one another morphologically more closely than do any other
pair of sympatric subspecies of _Sorex vagrans_. The exceptions may be
_S. v. vagrans_ and _S. v. obscurus_ which are geographically
sympatric in a few places although they may be ecologically separated.
_Specimens examined._--Total number, 9. BRITISH COLUMBIA, Vancouver
Island: Nanaimo, 3 BS; Barclay Sound, 1 AMNH; Goldstream, 5 BS.
_Marginal Records._--BRITISH COLUMBIA, Vancouver Island. (Anderson,
1947:19): Cape Scott; Victoria.
=Sorex vagrans insularis= Cowan
_Sorex obscurus insularis_ Cowan, Proc. Biol. Soc. Washington,
54:103, July 31, 1941.
_Type._--Adult female, skin and skull; No. 3110, Prov. Mus. British
Columbia; obtained on August 24, 1938, by T. T. and E. B. McCabe from
Smythe Island, Bardswell Group, British Columbia.
_Range._--Smythe, Townsend, and Reginald islands, British Columbia.
_Diagnosis._--Size medium; average and extreme measurements of 50
specimens from within the range of the subspecies are: total length,
122.3 (111-134); tail 52.6 (46-58); hind foot, 14.6 (13-15) (Cowan,
1941:107).
_Comparisons._--Smaller externally and cranially than _S. v.
longicauda_ and brown instead of blackish or grayish in winter pelage.
Skull broader than that of _S. v. calvertensis_ and color brown rather
than blackish or grayish in winter pelage.
_Remarks._--_S. v. insularis_ occurs together with _S. cinereus_ on
Townsend and Smythe islands. _S. vagrans_ far outnumbered the cinereus
shrew (Cowan, 1941:96).
_Records of occurrence._--BRITISH COLUMBIA (Cowan, 1941:104): Smythe
Island, Townsend Island, Reginald Island.
=Sorex vagrans calvertensis= Cowan
_Sorex obscurus calvertensis_ Cowan, Proc. Biol. Soc.
Washington, 54:103, July 31, 1941.
_Type._--Adult male, skin and skull; No. 1947, Prov. Mus. British
Columbia; obtained on July 14, 1937, by T. T. and E. T. McCabe from
Safety Cove, Calvert Island, British Columbia.
_Diagnosis._--Size medium; average and extreme measurements of 13
specimens from Calvert Island are: total length, 121.6 (109-129);
tail, 54.0 (52-58); hind foot, 14.7 (13-15) (Cowan, 1941:106).
Blackish or grayish in winter pelage.
_Comparisons._--Smaller externally and cranially and paler in winter
and summer than _S. v. longicauda_; for comparisons with _S. v.
insularis_ see account of that subspecies.
_Remarks_.--_S. v. calvertensis_ seems to be the only shrew on Calvert
and Banks islands.
_Records of occurrence._--BRITISH COLUMBIA (Cowan, 1941:103): Safety
Cove, Calvert Island; Larson Harbor, Banks Island.
_Marginal Records._--BRITISH COLUMBIA: Larson Harbor, Banks Island;
type locality.
=Sorex vagrans malitiosus= Jackson
_Sorex obscurus malitiosus_ Jackson, Proc. Biol. Soc. Washington,
32:23, April 11, 1919.
_Type._--Adult female, skin and skull; No. 8401; Mus. Vert. Zool.;
obtained on May 21, 1909, by H. S. Swarth from east side of Warren
Island, Alaska.
_Range._--Warren and Coronation islands, Alaska.
_Diagnosis._--Size medium; average and extreme measurements of 5
topotypes are: total length, 129.8 (126-135); tail, 56.4 (53-61); hind
foot, 15.4 (15-16). Color brownish in summer, brownish rather than
blackish in winter.
_Comparisons._--Somewhat more brownish than _S. v. longicauda_ but
resembling it in size; skull slightly more flattened and rostrum
broader. Larger than _S. v. elassodon_. Larger and relatively
longer-tailed than _S. v. alascensis_.
_Records of occurrence._--ALASKA (Jackson, 1928:130): Warren Island;
Coronation Island.
=Sorex vagrans elassodon= Osgood
_Sorex longicauda elassodon_ Osgood, N. Amer. Fauna, 21:35,
September 26, 1901.
_Sorex obscurus elassodon_, Elliott, Field Columb. Mus. Publ.
105, zool. ser. 6:450, 1905.
_Type._--Adult male, skin and skull; No. 100597, U. S. Biol. Surv.
Coll.; obtained on June 13, 1900, by W. H. Osgood from Cumshewa Inlet,
near old Indian village of Clew, Moresby Island, Queen Charlotte
Islands, British Columbia.
_Range._--Alaskan and British Columbian islands from Admiralty Island
south to Moresby Island.
_Diagnosis._--Size medium; average and extreme measurements of 4 from
the type locality are: total length, 126, (119-131); tail, 53.5
(52-55); hind foot, 13.8 (13-14). Color dark.
[Illustration: FIG. 17. Probable geographic ranges of the
subspecies of _Sorex vagrans_ on the coast of British Columbia
and southeastern Alaska.
1. _Sorex vagrans malitiosus_
2. _Sorex vagrans elassodon_
3. _Sorex vagrans prevostensis_
4. _Sorex vagrans calvertensis_
5. _Sorex vagrans insularis_
6. _Sorex vagrans longicauda_
7. _Sorex vagrans obscurus_
]
_Comparisons._--Smaller with relatively smaller tail and hind feet
than _S. v. longicauda_, but resembling it in color. Smaller and paler
than _S. v. prevostensis_ with relatively narrower rostrum. Larger,
darker, and with relatively longer tail than _S. v. obscurus_.
Resembles _S. v. alascensis_ but hind foot smaller and skull
relatively narrower. Smaller than _S. v. malitiosus_.
_Remarks._--In the northern part of its range _S. v. elassodon_ occurs
with _Sorex cinereus_. In the southern part it is the only shrew
present.
_Specimens examined._--Total number 93.
ALASKA: near Killisnoo, Admiralty Island, 2 BS; Kupreanof Island, 15
BS; Petersburg, Mitkof Island, 10 BS; Woewodski Island, 4 AMNH; Kasaan
Bay, Prince of Wales Island, 18 BS.
BRITISH COLUMBIA: Cumshewa Inlet, Moresby Island, 25 BS; Massett,
Graham Island, 6 BS; Queen Charlotte Islands, 13 AMNH.
_Marginal Records._--ALASKA: Hawk Inlet, Admiralty Island (Jackson,
1928:131); Kupreanof Island; Mitkof Island; St. John Harbor, Zarembo
Island (Jackson, 1928:131); Kasaan Bay, Prince of Wales Island; Duke
Island (Jackson, 1928:131). BRITISH COLUMBIA: Massett, Graham Island,
Queen Charlotte Islands; type locality; Langara Island, Queen
Charlotte Islands (Jackson, 1928:131). ALASKA: Forrester Island
(_ibid._); Rocky Bay, Dall Island (_ibid._); Shakan (really on
Kosciusko Island) (_ibid._); Point Baker (_ibid._); Kuiu Island
(_ibid._); Port Conclusion, Baranof Island (_ibid._).
=Sorex vagrans prevostensis= Osgood
_Sorex longicauda prevostensis_ Osgood, N. Amer. Fauna, 21:35,
September 26, 1901.
_Sorex obscurus prevostensis_, Elliott, Field Columb. Mus.
Publ. 105, zool. ser. 6:450, 1905.
_Type._--Adult male, skin and skull; No. 100618, U. S. Biol. Surv.
Coll.; obtained on July 3, 1900, by W. H. Osgood from north end of
Prevost Island (Kunghit Island on some maps) on coast of Houston
Stewart Channel, Queen Charlotte Islands, British Columbia.
_Range._--Known only from the type locality.
_Diagnosis._--Size medium; measurements of two specimens from the type
locality are: total length, 132, 142; tail, 53, 59; hind foot, 14, 15.
Color dark.
_Comparisons._--Larger and darker than _S. v. elassodon_. Resembles
_S. v. longicauda_ but darker, tail relatively somewhat shorter on the
average and rostrum relatively slightly broader.
_Specimens examined._--Total number, 14. BRITISH COLUMBIA: Prevost
Island, Queen Charlotte Group, 14 BS.
=Sorex vagrans alascensis= Merriam
_Sorex obscurus alascensis_ Merriam, N. Amer. Fauna, 10:76,
December 31, 1895.
_Sorex glacialis_ Merriam, Proc. Washington Acad. Sci., 2:16,
March 14, 1900, type from Point Gustavus, east side of
entrance to Glacier Bay, Alaska.
_S[orex]. alascensis_, Merriam, Proc. Washington Acad. Sci.,
2:18, March 14, 1900.
_[Sorex glacialis] alascensis_, Elliott, Field Columb. Mus.
Publ. 45, zool. ser. 2:372, 1901.
_Sorex alascensis alascensis_, Miller, U. S. Nat. Mus. Bull.,
79:16, December 31, 1912.
_Type._--Adult female, skin and skull; No. 73539, U. S. Biol. Surv.
Coll.; obtained on July 10, 1895, by C. P. Streator from Yakutat,
Alaska.
_Range._--The coast of southern Alaska from the vicinity of Juneau
west to include eastern part of the Kenai Peninsula.
_Diagnosis._--Size medium for the species; average and extreme
measurements of 9 specimens from 9 mi. W and 4 mi. N of Haines,
Alaska, are: total length, 110 (104-128); tail, 45.4 (41-52); hind
foot, 14 (14-14). Color grayish brown.
_Comparisons._--For comparison with _S. v. longicauda_ and _S. v.
elassodon_ see accounts of those subspecies. Resembles _S. v.
obscurus_ in color but differs in larger skull, longer hind foot and
in somewhat darker color. Larger and darker than _S. v.
shumaginensis_; the two intergrade near the base of the Kenai
Peninsula.
_Remarks._--This subspecies is transitional between the large, usually
dark subspecies of the southeastern Alaskan and British Columbian
coast and islands, and the smaller, paler subspecies of western and
interior Alaska. There seem to be no sharp breaks between _alascensis_
and _shumaginesis_. North of Haines, Alaska, size of shrews decreases
in a short distance across a narrow intergradational zone between
_alascensis_ and _obscurus_. Throughout most of its range _S. v.
alascensis_ occurs with _Sorex cinereus_.
_Specimens examined._--Total number, 88.
ALASKA: Orca, 1 BS; Montague Island, Prince William Sound, 2 BS;
Yakutat, 8 BS; north shore Yakutat Bay, 2 BS; Yakutat Bay, 1 BS; E
side Chilkat River, 100 ft., 9 mi. W and 4 mi. N Haines, 12 KU; 1 mi.
S Haines, 5 ft., 10 KU; 7 mi. SSE Haines, 10 ft., 2 KU; N end Sullivan
Island, 10 ft., 6 KU; SE end Sullivan Island, 10 ft., 2 KU; Glacier
Bay, 3 BS; Mendenhall River, 1 BS; Juneau, 36 BS.
BRITISH COLUMBIA: Sheslay River, 1 AMNH; headwaters Sheslay River, 1
AMNH.
_Marginal Records._--ALASKA: Valdez Narrows, Prince William Sound
(Jackson, 1928:128); north shore Yakutat Bay; east side Chilkat River,
100 ft., 9 mi. W and 4 mi. N Haines. BRITISH COLUMBIA: Sheslay River
(Jackson, 1928:128). ALASKA: Juneau; Glacier Bay; Montague Island,
Prince William Sound (ibid.); Port Nell Juan (ibid.).
=Sorex vagrans shumaginensis= Merriam
_Sorex alascensis shumaginensis_ Merriam, Proc. Washington
Acad. Sci., 2:18, March 14, 1900.
[_Sorex glacialis_] _shumaginensis_, Elliott, Field Columb.
Mus. Publ. 45, zool. ser. 2:373, 1901.
_Sorex obscurus shumaginensis_, Allen, Bull. American Mus.
Nat. Hist., 16:228, July 12, 1902.
_Type._--Adult male, skin and skull; No. 97993, U. S. Biol. Surv.
Coll.; obtained on July 17, 1899, by De Alton Saunders from Popof
Island, Shumagin Islands, Alaska. (Measured by C. Hart Merriam and
numbered 2210 in A. K. Fisher's catalog.)
_Range._--Southwestern Alaska from Seward Peninsula southeasterly to
western part of Kenai Peninsula and southwesterly to the southwestern
end of the Alaskan Peninsula.
_Diagnosis._--Size medium to small for the species; average and
extreme measurements of 6 specimens from King Cove, Alaska, are: total
length, 112.7 (107-118); tail, 48.3 (45-52); hind foot, 13.8 (13-14).
Tending toward the development of a tricolor pattern, the back
darkest, the sides buffy, and the venter paler.
_Comparisons._--Paler and more definitely tricolored than _S. v.
obscurus_; also with relatively shorter palate, narrower rostrum and
smaller teeth. For comparison with _S. v. alascensis_ see account of
that subspecies.
_Remarks._--_S. v. shumaginensis_ occurs together with _Sorex
cinereus_ over much of southwestern Alaska. Part of the range of
_shumaginensis_ falls within the tundra of the Arctic Life-zone. This
may be a partial explanation of the tricolored pattern of the animal.
_Sorex tundrensis_, _S. cinereus ugyunak_, and _S. cinereus haydeni_,
shrews which dwell mostly in treeless areas, are markedly tricolored,
or bicolored. _Sorex arcticus_, however, although tricolored, is found
in forested areas.
_Specimens examined._--Total number, 340. ALASKA: Sawtooth Mts., Nome
River, 2 AMNH; Nulato, 5 BS; St. Michaels, 1 BS; Bethel, 7 BS; Aniak,
1 BS; Skeventna River, 1 BS; 6 mi. WSW Snowshoe Lake, 1 KU; 1 mi. NE
Anchorage, 1 KU; Tyonek River, 48 BS; Hope, 15 BS; Hope, Mts. near, 13
BS; Moose Camp, 3 AMNH; Kenai Peninsula, 24 AMNH; Kakwok River, 80 mi.
up, 1 BS; Kakhtul River, 5 BS; Kakwok, 3 BS; Goodnews Bay, 1 BS; Lake
Aleknagik, 6 BS; Nushagak River, 25 mi. above Nushagak, 1 BS;
Dillingham, 1 BS; Nushagak Village, 15 BS; Homer, 1 AMNH; Kenai Mts.,
37 AMNH; Seldovia, 24 AMNH; Barabor, 1 AMNH; Caribou Camp, 7 AMNH;
Ugagik River, 3 BS; Becharof Lake, 8 BS; Cold Bay, 14 BS; Kanatak,
Portgage Bay, 4 BS; Chignik, 6 BS; Moller Bay, 1 BS; Alaska Peninsula,
near Popof Island, 6 AMNH; Frosty Peak, 15 BS; Morzhovoi Bay, 7 BS;
Ungu Island, 3 BS; Sand Point, Popof Island, 45 AMNH; Popof Island, 3
BS.
_Marginal Records._--ALASKA: Nome River; Nulato; Kuskokwim River, 200
mi. above Bethel, Crooked Creek (Jackson, 1928:126); 6 mi. WSW
Snowshoe Lake; Seldovia; mts. near Hope; Morhzovoi Bay; thence along
coast to St. Michael.
=Sorex vagrans obscurus= Merriam
_Sorex vagrans similis_ Merriam, N. Amer. Fauna, 5:34, July
31, 1891, _nec. S. similis_ Hensel, Zeitschr. der Deutsch.
Geolog. Gesellsch., 7:459, 1855 (= _Neomys similis_).
_Sorex obscurus_ Merriam, N. Amer. Fauna, 10:72, December 31,
1895, new name for _Sorex vagrans similis_ Merriam.
_Sorex obscurus obscurus_, Miller, Bull. U. S. Nat. Mus.,
79:15, December 31, 1912.
_Type._--Adult female, skin and skull; No. 23525/30943, U. S. Biol.
Surv. Coll.; obtained on August 26, 1890, by Vernon Bailey and B. H.
Dutcher from near Timber Creek, 8200 ft., Lemhi Mts., 10 mi. SSW
Junction (now Leadore), Lemhi Co., Idaho.
_Range._--Mountainous interior of western North America from central
Alaska east across Yukon and southwestern Northwest Territories to
northeastern Alberta, south in the mountains through north-central and
western Washington, Idaho, western Montana, Wyoming, Utah, and
Colorado, into northern New Mexico.
_Diagnosis._--Size medium to small for the species; average and
extreme measurements of 9 topotypes are: total length, 110.3
(105-117); tail, 46.4 (42-50); hind foot, 13.1 (12.5-13.5). Color
grayish or brownish gray in summer, light grayish in winter.
_Comparisons._--For comparisons with _S. v. setosus_, _S. v.
longicauda_, _S. v. alascensis_ and _S. v. shumaginensis_ see accounts
of those subspecies. Paler and slightly larger than S. v. soperi.
Larger than the subspecies from central Montana herein described as
new. Smaller than _S. v. neomexicanus_. Averaging larger in all
dimensions than _S. v. monticola_ with which _obscurus_ intergrades in
northern New Mexico and northern Arizona. Larger than _S. v. vagrans_
with more grayish rather than reddish fresh summer pelage and light
gray rather than dark grayish-black fresh winter pelage.
_Remarks._--Intergradation of _S. v. obscurus_ with _S. v. setosus_,
_S. v. longicauda_, _S. v. alascensis_, and the new subspecies from
Montana takes place in the usual way with specimens from intermediate
localities being intermediate in size and color. However the
relationship of _S. v. obscurus_ and _S. v. vagrans_ (as the latter
subspecies is defined in this study) is rather complicated. In
southern British Columbia where the two subspecies come together a
situation of remarkable complexity prevails. Series from some
localities seem to represent intergrades between _obscurus_ and
_vagrans_; from other localities some specimens seem to be referable
to one and some to the other subspecies; from other localities all
specimens seem referable to one subspecies. A similar situation is
seen in specimens from northeastern Washington, northern and central
Idaho, and extreme western Montana. The region mentioned is one of
extensive interfingering of life-zones. In southern British Columbia
the main axes of the rivers, valleys and mountain ranges are north and
south. Most of the valleys are in the Transition Life-zone; the
forests are rather dry and of pine with more or less isolated
hydrosere communities about streams and ponds. These hydrosere
situations are the habitat of _Sorex vagrans_. Shrews from these
situations are usually referable to _vagrans_. The high ridges and
mountain ranges are usually in the Canadian Life-zone or higher and
most of the shrews referable to _obscurus_ come from such places.
Marginal localities with regard to life-zone produce most of the
populations which seem to represent intergrades between the two
subspecies. Isolated areas of Canadian Life-zone, even though
surrounded with Transition Life-zone, often harbor a population of
_obscurus_, whereas the streams in the nearby dry valleys harbor
populations of _vagrans_. Farther south in the Rocky Mountain chain,
_obscurus_ seemingly intergrades regularly with _vagrans_. This
intergradation is seen in populations from several localities in Utah.
There the lower elevations west of the Wasatch and Uinta mountains
are inhabited by _S. v. vagrans_, the higher elevations by _obscurus_
and where the ranges of the two abut intergrading populations occur.
In these series of intergrades there are specimens which, using size
as a subspecific criterion, would unhesitatingly be assigned, as
individuals, to _obscurus_, and others would be assigned to _vagrans_,
but these individuals represent extremes of a normally variable
population. At Cuddy Mountain, Idaho, the two subspecies seemingly
abut without intergradation; anyhow the available specimens from this
locality are referable to one or the other subspecies and none is
intermediate. The situation just described understandably has been the
source of much anguish to students who sought to identify shrews from
the Rocky Mountains. The reason for the relationship just described
has been discussed at length in a previous section.