Canis lupus - Linnaeus, 1758
Gray Wolf
Other English Common Names: Grey Wolf, Wolf
Taxonomic Status: Accepted
Related ITIS Name(s): Canis lupus Linnaeus, 1758 (TSN 180596)
French Common Names: loup gris
Spanish Common Names: Lobo Gris
Unique Identifier: ELEMENT_GLOBAL.2.105212
Element Code: AMAJA01030
Informal Taxonomy: Animals, Vertebrates - Mammals - Carnivores
Image 12037

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Kingdom Phylum Class Order Family Genus
Animalia Craniata Mammalia Carnivora Canidae Canis
Genus Size: C - Small genus (6-20 species)
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Concept Reference
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Concept Reference: Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/.
Concept Reference Code: B93WIL01NAUS
Name Used in Concept Reference: Canis lupus
Taxonomic Comments: Based on recent genetic studies, Wilson et al. (2000) concluded that the eastern timber wolf (Canis lupus lycaon) and the red wolf (Canis rufus) are sister taxa and are best considered to be conspecific. Additionally, Wilson et al. found that these two taxa form a North American lineage with the coyote (Canis latrans) that is distinct from that of the gray wolf (Canis lupus), which is Eurasian in origin. Wilson et al. (2000, 2003) proposed that the eastern timber wolf (Canis lycaon) be recognized as a species distinct from the gray wolf (C. lupus). Nowak (2002) presented an analysis of cranial morphology of recent and Pleistocene Canis and concluded that Canis rufus is a valid species and that lycaon may be a hybrid between Canis rufus and western Canis lupus.

In a recent checklist of North American mammals, Baker et al. (2003) accepted C. lycaon and C. lupus as separate species as proposed by Wilson et al. (2000, 2003). Without explanation they retained the red wolf (Canis rufus) as a third North American wolf species. Wozencraft (in Wilson and Reeder 2005) recognized one Northern Hemisphere wolf species (Canis lupus) and listed rufus and lycaon as subspecies, noting that rufus appears to be a hybrid. In view of the unstable taxonomy of North American wolves and pending further information, this database retains the traditional arrangement of two wolf species in North America (C. lupus and C. rufus), with lycaon treated as a subspecies of C. lupus.

Recently, the eastern timber wolf and coyote have come into contact and have subsequently hybridized (Wilson et al. 2000). For example, genetic transfer of coyote mitochondrial DNA into eastern wolf (Canis lupus lycaon) populations has occurred through hybridization in a contiguous geographic region in Minnesota, Ontario, and Quebec; the frequency of coyote-type mtDNA in these wolf populations is greater than 50%; no coyotes sampled had a wolf-derived mtDNA genotype; probably hybridization is occurring between male wolves and female coyotes in regions where coyotes only recently have become abundant following conversion of forests to farmlands (Lehman et al. 1991).

Genetic data from northwestern Canada suggests the existence of a large panmictic population resulting from extensive movements of individuals and packs and from natural and human impacts on pack structure and function (Kennedy et al. 1991).

Wayne et al. (1992) examined mtDNA variability in North America, Europe, and southern Asia and found 18 mtDNA genotypes, seven derived from hybridization with coyotes, four confined to the New World, six confined to the Old World, and one shared by both areas. Genetic differentiation among populations is small but significant. In the Old World most localities have a single unique genotype, whereas in the New World several genotypes occur at most localities and three of the five genotypes are nearly ubiquitous. They concluded that apparent genetic differences among extant wolf populations may be a recent phenomenon reflecting population declines and habitat fragmentation rather than a long history of genetic isolation.
Conservation Status
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NatureServe Status

Global Status: G5
Global Status Last Reviewed: 04Apr2016
Global Status Last Changed: 04Apr2016
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G5 - Secure
Reasons: Holarctic distribution; survives in wilderness that is not subject to human population pressures; extirpated from most of contiguous U.S. due to human-caused direct mortality; reintroduced populations in Yellowstone and central Idaho have been increasing rapidly; many (tens of thousands) remain in Canada/Alaska, about 2000 south of Canada, 100,000+ in Palearctic. NatureServe rank calculator version 3.1 yielded a rank of G5? and this species is nationally ranked N5 in Canada. 
Nation: United States
National Status: N4 (05Sep1996)
Nation: Canada
National Status: N5 (19Feb2016)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alabama (SX), Alaska (S4), Arizona (S1), Arkansas (SX), California (S1), Colorado (SX), Connecticut (SX), Delaware (SX), District of Columbia (SX), Florida (SX), Georgia (SX), Idaho (S4), Illinois (S1), Indiana (SX), Iowa (SX), Kansas (SX), Kentucky (SX), Maine (SH), Maryland (SX), Massachusetts (SX), Michigan (S4), Minnesota (S3), Missouri (SX), Montana (S4), Navajo Nation (SX), Nebraska (SX), Nevada (SH), New Hampshire (SX), New Jersey (SX), New Mexico (S1), New York (SX), North Carolina (SX), North Dakota (SX), Ohio (SX), Oklahoma (SX), Oregon (S1S2), Pennsylvania (SX), Rhode Island (SX), Tennessee (SX), Texas (SX), Utah (SX), Vermont (SX), Virginia (SX), Washington (S1), West Virginia (SX), Wisconsin (S4), Wyoming (S1)
Canada Alberta (S4), British Columbia (S4S5), Labrador (S3S4), Manitoba (S5), New Brunswick (SX), Newfoundland Island (SNA), Northwest Territories (S5), Nova Scotia (SX), Nunavut (S5), Ontario (S4), Prince Edward Island (SX), Quebec (S4S5), Saskatchewan (S4), Yukon Territory (S4)

Other Statuses

Implied Status under the U.S. Endangered Species Act (USESA): PS:LE, LT, XN, PDL
Comments on USESA: This species has had several federal status updates over the years, due to lawsuits or threat of lawsuits against USFWS delisting efforts. For the latest status information see the FWS species profile page at http://ecos.fws.gov/tess_public/profile/speciesProfile?spcode=A00D. Canis lupus is currently listed Endangered in the contiguous United States and Mexico; USFWS (2013) proposes to remove it from the List of Endangered and Threatened Wildlife but maintain endangered status for the Mexican wolf by listing it as a subspecies (Canis lupus baileyi).

The most recent updates as of May 2016 are:

In a 12-month finding on a petition to list the Alexander Archipelago wolf (Canis lupus ligoni) as an endangered or threatened species and to designate critical habitat, USFWS (2016) found that listing this wolf is not warranted at this time throughout all or a significant portion of its range. They also found that the wolf population on Prince of Wales Island (POW) does not meet the criteria of the Service?s DPS policy, and, therefore, it does not constitute a listable entity under the Act.

A final rule published in the Federal Register on May 1, 2017 amends the List by removing gray wolves in Wyoming. Background: USFWS (2015) issued a final rule to comply with court orders that reinstate the regulatory protections under the Endangered Species Act for the gray wolf in Wyoming and the western Great Lakes. Pursuant to the U.S. District Court for the District of Columbia court order dated September 23, 2014, this rule reinstates the April 2, 2009 final rule regulating the gray wolf in the State of Wyoming as a nonessential experimental population. Gray wolves in Montana, Idaho, the eastern third of Washington and Oregon, and north-central Utah retain their delisted status and are not impacted by this final rule. In addition, pursuant to the U.S. District Court for the District of Columbia court order dated December 19, 2014, this rule reinstates the March 9, 1978 final rule as it relates to gray wolves in the western Great Lakes including endangered status for gray wolves in all of Wisconsin and Michigan, the eastern half of North Dakota and South Dakota, the northern half of Iowa, the northern portions of Illinois and Indiana, and the northwestern portion of Ohio; threatened status for gray wolves in Minnesota; critical habitat for gray wolves in Minnesota and Michigan; and the rule promulgated under section 4(d) of the ESA for gray wolves in Minnesota.

USFWS (2015) has determined that a petition to reclassify all gray wolves in the conterminous United States, except for the Mexican wolf in the Southwest, as a threatened species under the Endangered Species Act (ESA) does not present substantial information indicating that reclassification may be warranted. As a result, the Service will take no further action on the petition, which was submitted by the Humane Society of the United States and 22 other petitioners in January.

Due to a Federal court decision, wolves in the western Great Lakes area (including Michigan, Minnesota, and Wisconsin) were relisted under the Endangered Species Act, effective December 19, 2014. This rule reinstates threatened status for gray wolves in Minnesota.

Implied Status under the Committee on the Status of Endangered Wildlife in Canada (COSEWIC):PS:SC,NAR,DD
Comments on COSEWIC: Subspecies lycaon is designated Special Concern. Subspecies occidentalis and nubilus are designated Not at Risk and subspecies arctos is designated Data Deficient.

IUCN Red List Category: LC - Least concern
Convention on International Trade in Endangered Species Protection Status (CITES): Appendix II

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: Formerly throughout North America south through much of Mexico; also Europe and Asia. Replaced by the red wolf in the southeastern United States. Today found south of Canada only in northern Mexico (no recent confirmed reports; extirpated or maybe a few in eastern Sonora, Chihuahua, and/or Zacatecas?), a few areas in the Rocky Mountains (northwestern Montana, reintroduction sites in Wyoming and Idaho), northwestern Great Lakes region (northeastern third of Minnesota, northern Wisconsin, Michigan Upper Peninsula), and Cascade Mountains of northern Washington. Formerly much more numerous in the Rocky Mountain states than in the southwestern U.S. (Johnson 1991). Extirpated in much of southern Canada (see Theberge [1992] and Can. Field-Nat. 106:138 for range/status map); remains in 85% of former total Canadian range (Theberge 1991).

In 1995, wolf reintroductions were initiated in the Yellowstone ecosystem and in central Idaho (nonessential experimental populations) (USFWS 1994; Federal Register, 16 August 1994; Bangs and Fritts 1993; End. Sp. Bull. 20(4):4-5). See Bangs et al. (1998) for information on the status of gray wolf restoration in Montana, Idaho, and Wyoming. In 1998, USFWS (Federal Register, 12 January 1998) announced its intention to reintroduce the Mexican gray wolf (subspecies baileyi) into Arizona and New Mexico (Apache and Gila national forests, also possibly White Sands Missile Range).

Wolf observations in the Dakotas have increased in recent years, likely related to range expansion and population increases in adjacent areas, especially Minnesota; most occurrences have been of young individuals, suggesting dispersal (Licht and Fritts 1994).

Grewal et al. (2004) used genetic data to determine that the wolf population in Algonquin Provincial Park in Ontario, Canada, is a southern part of a larger metapopulation of Canis lycaon (or Canis lupus lycaon).

Number of Occurrences: 81 to >300
Number of Occurrences Comments: Because wolves are wide-ranging it is difficult to estimate the number of distinct occurrences. The 30-km separation between EOs given in EOSPECS is a compromise figure. It could have been smaller in the northern USA where pack home ranges in Minnesota were 130 km2, or larger in Alaska where home ranges up to 13,000 km2 are reported (Mech and Frenzel 1971, Burkholder 1959).

Population Size: 10,000 to >1,000,000 individuals
Population Size Comments: Canada: about 50,000-58,500 in 1990; subject to hunting and trapping in all but a few percent of the range (Cohn 1990, Theberge 1991).

Alaska: about 6000 (Theberge 1991).

In 1998, there were at least 65 wolves in northwestern Montana, at least 122 in central Idaho, and 116 in the Greater Yellowstone Area (Bangs et al. 1998). In 2004, the northern Rocky Mountains population included more than 800 wolves (USFWS 2006).

Isle Royale population was about 14-16 in 1995. Michigan Upper Peninsula population was 112 in 1996/1997 (End. Sp. Bull. 22(3):21). Wisconsin: 150 in 1997-1997 (End. Sp. Bull. 22(3):21). Minnesota: nearly 2000 in mid-1990s (Mladenoff et al. 1997).

Southwestern U.S. and Mexico: none in the U.S. and very few if any in Mexico.

See Jhala and Giles (1991) for information on status in northwestern India (several hundred remain). Population estimates for the 1980s: former Soviet Union, 88,000; Inner Mongolia, less than 10,000; Yugoslavia, 2000-5000; Poland, about 1000; Spain, about 1000; 2000 or less in each of Iran, Afganistan, India, and Romania (see Theberge 1991). Population in the USSR in the mid-1940s was about 200,000-300,000; reduced to lowest numbers in history by the 1960s; increased to 1940s level by the 1980s; about 40,000 in Russia in 1995 (Yuli Gabur 1996, Natural Areas News 1(2):8-9).

Overall Threat Impact Comments: Exterminated from large areas through trapping, shooting, poisoning, and reduction in prey populations (ungulate herds). Threatened by direct human-caused mortality and possibly habitat loss. Landscape change resulting from development may interfere with restoration in some areas (Carroll et al. 2003). Heavily persecuted in former Soviet Union and in China.

The threats to the northern Rocky Mountain wolf population have been reduced or eliminated as evidenced by the population exceeding the numerical, distributional, and temporal recovery goals each year since 2002 (USFWS 2006).

Short-term Trend Comments: The Northern Rocky Mountain population increased steadily from 1979 to 2004 (USFWS 2006). Wolf recovery in the Greater Yellowstone Ecosystem and in central Idaho has progressed faster than predicted (Bangs et al. 1998).

Currently expanding in the northcentral United States. Mech et al. (1995) documented dispersal and recolonization from northern Minnesota to Wisconsin and Michigan.

Wolf recovery has been noted in some areas of Europe (see Cohn 1990). Increasing in Russia in the mid-1990s (Y. Gabur). Trends elsewhere are unknown.

Other NatureServe Conservation Status Information

Inventory Needs: Determine distribution in Europe and Asia.

Protection Needs: Need to protect several large tracts of lands as rangeland for wolf packs.

Distribution
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Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) Formerly throughout North America south through much of Mexico; also Europe and Asia. Replaced by the red wolf in the southeastern United States. Today found south of Canada only in northern Mexico (no recent confirmed reports; extirpated or maybe a few in eastern Sonora, Chihuahua, and/or Zacatecas?), a few areas in the Rocky Mountains (northwestern Montana, reintroduction sites in Wyoming and Idaho), northwestern Great Lakes region (northeastern third of Minnesota, northern Wisconsin, Michigan Upper Peninsula), and Cascade Mountains of northern Washington. Formerly much more numerous in the Rocky Mountain states than in the southwestern U.S. (Johnson 1991). Extirpated in much of southern Canada (see Theberge [1992] and Can. Field-Nat. 106:138 for range/status map); remains in 85% of former total Canadian range (Theberge 1991).

In 1995, wolf reintroductions were initiated in the Yellowstone ecosystem and in central Idaho (nonessential experimental populations) (USFWS 1994; Federal Register, 16 August 1994; Bangs and Fritts 1993; End. Sp. Bull. 20(4):4-5). See Bangs et al. (1998) for information on the status of gray wolf restoration in Montana, Idaho, and Wyoming. In 1998, USFWS (Federal Register, 12 January 1998) announced its intention to reintroduce the Mexican gray wolf (subspecies baileyi) into Arizona and New Mexico (Apache and Gila national forests, also possibly White Sands Missile Range).

Wolf observations in the Dakotas have increased in recent years, likely related to range expansion and population increases in adjacent areas, especially Minnesota; most occurrences have been of young individuals, suggesting dispersal (Licht and Fritts 1994).

Grewal et al. (2004) used genetic data to determine that the wolf population in Algonquin Provincial Park in Ontario, Canada, is a southern part of a larger metapopulation of Canis lycaon (or Canis lupus lycaon).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, ALextirpated, ARextirpated, AZ, CA, COextirpated, CTextirpated, DCextirpated, DEextirpated, FLextirpated, GAextirpated, IAextirpated, ID, IL, INextirpated, KSextirpated, KYextirpated, MAextirpated, MDextirpated, ME, MI, MN, MOextirpated, MT, NCextirpated, NDextirpated, NEextirpated, NHextirpated, NJextirpated, NM, NNextirpated, NV, NYextirpated, OHextirpated, OKextirpated, OR, PAextirpated, RIextirpated, TNextirpated, TXextirpated, UTextirpated, VAextirpated, VTextirpated, WA, WI, WVextirpated, WY
Canada AB, BC, LB, MB, NBextirpated, NF, NSextirpated, NT, NU, ON, PEextirpated, QC, SK, YT

Range Map
Note: Range depicted for New World only. The scale of the maps may cause narrow coastal ranges or ranges on small islands not to appear. Not all vagrant or small disjunct occurrences are depicted. For migratory birds, some individuals occur outside of the passage migrant range depicted. For information on how to obtain shapefiles of species ranges see our Species Mapping pages at www.natureserve.org/conservation-tools/data-maps-tools.

Range Map Compilers: Sechrest, 2002


U.S. Distribution by County Help
State County Name (FIPS Code)
AK Haines (02100), Juneau (02110), Ketchikan Gateway (02130), Prince of Wales-Outer Ketchikan (CA) (02201), Skagway-Hoonah-Angoon (CA) (02232), Wrangell-Petersburg (CA) (02280), Yakutat (02282)
CA Lassen (06035)*, Modoc (06049)*, San Bernardino (06071)*
ID Adams (16003), Benewah (16009), Blaine (16013), Boise (16015), Bonner (16017), Boundary (16021), Camas (16025), Clark (16033), Clearwater (16035), Custer (16037), Elmore (16039), Fremont (16043), Gem (16045), Idaho (16049), Kootenai (16055), Latah (16057), Lemhi (16059), Madison (16065), Shoshone (16079), Teton (16081), Valley (16085)
IL Carroll (17015), Grundy (17063), Jo Daviess (17085), Kane (17089), La Salle (17099), Lake (17097), Marshall (17123), Pike (17149), Stephenson (17177), Whiteside (17195)
MI Chippewa (26033)*, Iron (26071), Keweenaw (26083)
MT Beaverhead (30001), Broadwater (30007), Carbon (30009), Cascade (30013), Deer Lodge (30023), Flathead (30029), Gallatin (30031), Glacier (30035), Granite (30039), Jefferson (30043), Judith Basin (30045), Lake (30047), Lewis and Clark (30049), Lincoln (30053), Madison (30057), Meagher (30059), Mineral (30061), Missoula (30063), Park (30067), Pondera (30073), Powell (30077), Ravalli (30081), Sanders (30089), Silver Bow (30093), Stillwater (30095), Sweet Grass (30097), Teton (30099), Wheatland (30107)
NM Catron (35003)*, Hidalgo (35023)*, Socorro (35053)*
OR Baker (41001), Clackamas (41005)*, Deschutes (41017)*, Douglas (41019)*, Grant (41023), Jackson (41029), Josephine (41033)*, Klamath (41035), Lake (41037), Lane (41039)*, Malheur (41045)*, Umatilla (41059), Union (41061), Wallowa (41063)
UT Box Elder (49003)*, Duchesne (49013)*, San Juan (49037)*, Summit (49043)*, Washington (49053)*, Weber (49057)*
WA Asotin (53003)+, Chelan (53007)+, Clallam (53009)+, Clark (53011)+, Columbia (53013)+, Cowlitz (53015)+, Douglas (53017)+, Ferry (53019)+, King (53033)+, Kittitas (53037)+, Klickitat (53039)+, Lewis (53041)+, Lincoln (53043)+, Mason (53045)+, Okanogan (53047)+, Pend Oreille (53051)+, Pierce (53053)+, Skagit (53057)+, Skamania (53059)+, Snohomish (53061)+, Spokane (53063)+, Stevens (53065)+, Whatcom (53073)+, Yakima (53077)+
WI Ashland (55003), Bayfield (55007), Burnett (55013), Douglas (55031), Dunn (55033), Florence (55037), Iron (55051), Jackson (55053), Juneau (55057), Langlade (55067), Lincoln (55069), Marathon (55073), Marinette (55075), Marquette (55077), Menominee (55078), Monroe (55081), Oconto (55083), Oneida (55085), Polk (55095), Price (55099), Rusk (55107), Sawyer (55113), Shawano (55115), Vilas (55125), Washburn (55129)
WY Albany (56001)*, Big Horn (56003), Campbell (56005)*, Carbon (56007)*, Converse (56009)*, Crook (56011)*, Fremont (56013), Hot Springs (56017), Johnson (56019), Laramie (56021)*, Lincoln (56023), Natrona (56025)*, Niobrara (56027)*, Park (56029), Platte (56031)*, Sheridan (56033)*, Sublette (56035), Sweetwater (56037)*, Teton (56039), Washakie (56043), Weston (56045)*
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
04 Beartrap-Nemadji (04010301)+, Bad-Montreal (04010302)+, Lake Superior (04020300)+, Oconto (04030104)+, Peshtigo (04030105)+, Brule (04030106)+, Menominee (04030108)+, Upper Fox (04030201)+, Wolf (04030202)+, St. Marys (04070001)+*, Lake Huron (04080300)+*
07 Upper St. Croix (07030001)+, Namekagon (07030002)+, Lower St. Croix (07030005)+, La Crosse-Pine (07040006)+, Black (07040007)+, Upper Chippewa (07050001)+, Flambeau (07050002)+, South Fork Flambeau (07050003)+, Jump (07050004)+, Red Cedar (07050007)+, Apple-Plum (07060005)+, Upper Wisconsin (07070001)+, Lake Dubay (07070002)+, Castle Rock (07070003)+, Pecatonica (07090003)+, Lower Rock (07090005)+, The Sny (07110004)+, Upper Illinois (07120005)+, Upper Fox (07120006)+, Lower Fox (07120007)+, Lower Illinois-Senachwine Lake (07130001)+, Vermilion (07130002)+
09 St. Marys (09040001)+, Belly (09040002)+
10 Red Rock (10020001)+, Beaverhead (10020002)+, Ruby (10020003)+, Big Hole (10020004)+, Jefferson (10020005)+, Boulder (10020006)+, Madison (10020007)+, Gallatin (10020008)+, Upper Missouri (10030101)+, Upper Missouri-Dearborn (10030102)+, Smith (10030103)+, Sun (10030104)+, Belt (10030105)+, Two Medicine (10030201)+, Cut Bank (10030202)+, Marias (10030203)+, Teton (10030205)+, Arrow (10040102)+, Judith (10040103)+, Upper Musselshell (10040201)+, Milk Headwaters (10050001)+, Yellowstone Headwaters (10070001)+, Upper Yellowstone (10070002)+, Shields (10070003)+, Upper Yellowstone-Lake Basin (10070004)+, Stillwater (10070005)+, Clarks Fork Yellowstone (10070006)+, Upper Wind (10080001)+, Little Wind (10080002)+*, Lower Wind (10080005)+*, Badwater (10080006)+*, Upper Bighorn (10080007)+, Nowood (10080008)+, Greybull (10080009)+, Big Horn Lake (10080010)+*, North Fork Shoshone (10080012)+, South Fork Shoshone (10080013)+, Shoshone (10080014)+, Little Bighorn (10080016)+*, Upper Tongue (10090101)+*, Middle Fork Powder (10090201)+, Upper Powder (10090202)+*, South Fork Powder (10090203)+*, Salt (10090204)+*, Crazy Woman (10090205)+, Clear (10090206)+, Little Powder (10090208)+*, Upper Little Missouri (10110201)+*, Antelope (10120101)+*, Dry Fork Cheyenne (10120102)+*, Upper Cheyenne (10120103)+*, Lance (10120104)+*, Lightning (10120105)+*, Angostura Reservoir (10120106)+*, Beaver (10120107)+*, Hat (10120108)+*, Upper Belle Fourche (10120201)+*, Lower Belle Fourche (10120202)+*, Redwater (10120203)+*, Niobrara Headwaters (10150002)+*, Pathfinder-Seminoe Reservoirs (10180003)+*, Sweetwater (10180006)+*, Middle North Platte-Casper (10180007)+*, Glendo Reservoir (10180008)+*, Upper Laramie (10180010)+*, Crow (10190009)+*, Upper Lodgepole (10190015)+*
13 Rio Grande-Albuquerque (13020203)+*, Elephant Butte Reservoir (13020211)+*, Mimbres (13030200)+*, Playas Lake (13030201)+*
14 Upper Dolores (14030002)+*, Upper Colorado-Kane Springs (14030005)+*, Upper Green (14040101)+, New Fork (14040102)+, Bitter (14040105)+*, Blacks Fork (14040107)+*, Muddy (14040108)+*, Great Divide closed basin (14040200)+*, Little Snake (14050003)+*, Muddy (14050004)+*, Duchesne (14060003)+*, Strawberry (14060004)+*
15 Fort Pierce Wash (15010009)+*, Upper Gila (15040001)+*, Animas Valley (15040003)+*, San Simon (15040006)+*, Cloverdale (15080303)+*
16 Upper Bear (16010101)+*, Central Bear (16010102)+*, Lower Weber (16020102)+*, Northern Great Salt Lake Desert (16020308)+*
17 Upper Kootenai (17010101)+, Fisher (17010102)+, Yaak (17010103)+, Lower Kootenai (17010104)+, Moyie (17010105)+, Elk (17010106)+, Upper Clark Fork (17010201)+, Flint-Rock (17010202)+, Blackfoot (17010203)+, Middle Clark Fork (17010204)+, Bitterroot (17010205)+, North Fork Flathead (17010206)+, Middle Fork Flathead (17010207)+, Flathead Lake (17010208)+, South Fork Flathead (17010209)+, Stillwater (17010210)+, Swan (17010211)+, Lower Flathead (17010212)+, Lower Clark Fork (17010213)+, Pend Oreille Lake (17010214)+, Priest (17010215)+, Pend Oreille (17010216)+, Upper Coeur D'alene (17010301)+, South Fork Coeur D'alene (17010302)+, Coeur D'alene Lake (17010303)+, St. Joe (17010304)+, Upper Spokane (17010305)+, Hangman (17010306), Lower Spokane (17010307), Little Spokane (17010308)+, Franklin D. Roosevelt Lake (17020001), Kettle (17020002), Colville (17020003), Sanpoil (17020004), Chief Joseph (17020005), Okanogan (17020006), Similkameen (17020007), Methow (17020008), Lake Chelan (17020009), Upper Columbia-Entiat (17020010), Wenatchee (17020011), Upper Crab (17020013), Banks Lake (17020014), Upper Yakima (17030001), Naches (17030002), Lower Yakima, Washington (17030003), Snake headwaters (17040101)+, Gros Ventre (17040102)+, Greys-Hobock (17040103)+, Upper Henrys (17040202)+, Lower Henrys (17040203)+, Teton (17040204)+, Beaver-Camas (17040214)+, Medicine Lodge (17040215)+, Birch (17040216)+, Big Lost (17040218)+, Big Wood (17040219)+, Camas (17040220)+, Little Wood (17040221)+, North and Middle Forks Boise (17050111)+, Boise-Mores (17050112)+, South Fork Boise (17050113)+, Lower Boise (17050114)+, Upper Malheur (17050116)+*, South Fork Payette (17050120)+, Middle Fork Payette (17050121)+, Payette (17050122)+, North Fork Payette (17050123)+, Weiser (17050124)+, Brownlee Reservoir (17050201)+, Burnt (17050202)+*, Powder (17050203)+, Hells Canyon (17060101)+, Imnaha (17060102)+, Lower Snake-Asotin (17060103)+, Upper Grande Ronde (17060104)+, Wallowa (17060105)+, Lower Grande Ronde (17060106)+, Lower Snake-Tucannon (17060107), Palouse (17060108)+, Upper Salmon (17060201)+, Pahsimeroi (17060202)+, Middle Salmon-Panther (17060203)+, Lemhi (17060204)+, Upper Middle Fork Salmon (17060205)+, Lower Middle Fork Salmon (17060206)+, Middle Salmon-Chamberlain (17060207)+, South Fork Salmon (17060208)+, Lower Salmon (17060209)+, Little Salmon (17060210)+, Upper Selway (17060301)+, Lower Selway (17060302)+, Lochsa (17060303)+, Middle Fork Clearwater (17060304)+, South Fork Clearwater (17060305)+, Clearwater (17060306)+, Upper North Fork Clearwater (17060307)+, Lower North Fork Clearwater (17060308)+, Middle Columbia-Lake Wallula (17070101), Walla Walla (17070102)+, Umatilla (17070103)+, Middle Columbia-Hood (17070105), Klickitat (17070106), North Fork John Day (17070202)+, Middle Fork John Day (17070203)+, Upper Deschutes (17070301)+*, Little Deschutes (17070302)+, Lower Columbia-Sandy (17080001), Lewis (17080002), Upper Cowlitz (17080004), Lower Cowlitz (17080005), Middle Fork Willamette (17090001)+*, Mckenzie (17090004)+*, Clackamas (17090011)+*, Lower Willamette (17090012), Lower Chehalis (17100104), North Umpqua (17100301)+*, South Umpqua (17100302)+*, Upper Rogue (17100307)+, Middle Rogue (17100308)+*, Lower Rogue (17100310)+*, Fraser (17110001), Strait of Georgia (17110002), Nooksack (17110004), Upper Skagit (17110005), Sauk (17110006), Lower Skagit (17110007), Stillaguamish (17110008), Skykomish (17110009), Snoqualmie (17110010), Lake Washington (17110012), Duwamish (17110013), Puyallup (17110014), Nisqually (17110015), Skokomish (17110017), Puget Sound (17110019), Dungeness-Elwha (17110020), Summer Lake (17120005)+
18 Williamson (18010201)+, Sprague (18010202)+, Upper Klamath Lake (18010203)+, Lost (18010204)+*, Upper Klamath (18010206)+, Upper Pit (18020002)+*, Honey-Eagle Lakes (18080003)+*, Southern Mojave (18100100)+*
19 Southeast Mainland (19010101)+, Ketchikan (19010102)+, Prince of Wales (19010103)+, Mainland (19010201)+, Kuiu-Kupreanof-Mitkof-Etolin-Zarembo-Wrangell Isla (19010202)+, Baranof-Chichagof Islands (19010203)+, Admiralty Island (19010204)+, Lower Iskut (19010205)+, Lynn Canal (19010301)+, Glacier Bay (19010302)+, Chilkat-Skagway Rivers (19010303)+, Taku River (19010304)+, Yakutat Bay (19010401)+, Icy Strait-Chatham Strait (19010500)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Basic Description: Wolf; a large dog-like mammal.
General Description: Largest of the wild dogs; total length to 205 cm, tail to 50 cm, nose pad averaging 31 mm or more in diameter; upper canine more than 12 mm in anteroposterior diameter at base and not extending below level of anterior mental foramen when lower jaw is in place; peleage varies from nearly black to white, some shade of gray in most areas; condylobasal length of skull 203-269 mm (Hall 1981).
Diagnostic Characteristics: Differs from the coyote in larger nose pad (greater than 1 inch vs. less than 1 inch), more rounded ears, larger anteroposterior diameter of upper canine at gum level (more than 11 mm vs. less than 11 mm), larger heel pad on forefoot (more than 1.25 inches vs. less than 1.25 inches), longer skull (more than 215 mm and 2.5 mm vs. less than 215 mm and 205 mm, for males and females, respectively), and relatively shorter canines (in coyote, tips of upper canines extend below level of anterior mental foramina when lower jaw is in place); also, gray wolf holds the tail high when running, coyote holds it low (see Hall 1981 and Hoffmeister 1986 for further details). In some parts of central and eastern North America, coyote approaches wolf in certain characteristics, due to interbreeding. Differs from the red wolf in larger size, longer skull (condylobasal length more than 213 mm and 203 mm vs. less than these measurements for males and females, respectively), and in certain features og the molars (see Hall 1981); however, the red wolf actually may be a coyote-gray wolf hybrid (see GTAXCOM for CANIS RUFUS). Differs from the domestic dog in generally larger size, broader nose pad, more massive skull with heavier teeth, rostrum relatively longer, supraoccipital shield larger and projecting farther posteriorly, front foot track longer and narrower (Hoffmeister 1986).
Reproduction Comments: Breeds late fall/early winter in south, February-March in north. Gestation lasts about 2 months. Young are born in March and early April in the south (Hoffmeister 1986), late April in northwestern Montana, late May-early June in Northwest Territories (Heard and Williams 1992). Litter size is 4-10 (average 6-7); 1 litter/year. Only the dominant male/female mate and rear offspring. Pups emerge from the den in about 3 weeks. Pups are weaned in 50 days (also reported as 5 weeks). Young and parents vacate the den when young are about 3 months old (Hoffmeister 1986). Some offspring remain with the pack, others disperse as they mature. Breeding first occurs in the second or third year (Hoffmeister 1986). Lone wolves generally do not successfully rear young, but they may if food is abundant (Boyd and Jimenez, 1994, J. Mamm. 75:14-17).
Ecology Comments: Territorial throughout the year in most areas (but see Migration/Mobility comments). Packs consist of one or more family groups (generally 2-8 members, up to 21) with dominance hierarchy. In the Glacier National Park area, packs generally include 8-12 individuals (Bangs and Fritts 1993). Not uncommonly solitary; lone wolves may move through territories of established packs (e.g., see Thurber and Peterson 1993).

Population density is low; at Isle Royale National Park, Michigan, peak density was 9/100 sq km. Population density on Isle Royale followed trends in food supply (moose), with lag of 2-3 years (Peterson and Page 1988).

Generally wolves are not instrumental in causing prey declines; effect varies with other circumstances. In Quebec, winter weather appeared to affect deer population trend more than did wolf predation (Potvin et al. 1992). In south-central Alaska, wolf predation may have limited caribou recruitment (Bergerud and Ballard 1988), though winter starvation also was proposed as a significant poplation control. May take livestock as secondary prey when deer fawns (the primary summer prey) are less vulnerable due to better prenatal nutrition resulting from mild winter (USFWS 1990). In Minnesota, snow-induced changes in deer distribution and mobility resulted in changes in wolf movement patterns, sociality, and feeding behavior (when snow was shallow, wolves traveled farther and more often, spent less time with pack members, and used conifer cover less and killed fewer deer there) (Fuller 1991).

Non-Migrant: Y
Locally Migrant: N
Long Distance Migrant: N
Mobility and Migration Comments: Wolves in far northwestern North America may move as required to remain with migratory caribou.

Home ranges very large but very variable as well, generally ranging from less 100 to 10,000s of square kilometers. In Minnesota, Fritts and Mech (1981) found territory sizes ranging from 195 to 555 square kilometers; in south to central Alaska, Ballard et al. (1987) reported territory sizes from 943 to 2541 square kilometers; in the southern Yukon, Hayes (1992) found territory sizes of 583 to 794 km square kilometers; in the Kenai Peninsula, Alaska, Peterson et al. (1984) found average territory sizes of 638 square kilometers; and in coastal forests of Vancouver Island, Atkinson and Janz (1994) found territory sizes from 100 to 400 square kilometers. Packs that depend on barren ground caribou migrate with the caribou as far as 360 km (Kuyt 1972; Mech 1970, 1974). In the Glacier National Park area, territory size averages around 780 sq km (Bangs and Fritts 1993).

In the Northwest Territories and western Nunavut, Walton et al. (2001) fitted 23 wolves in 19 different packs with collar-mounted satellite transmitters. Annual home-range sizes (95% minimum convex polygon) averaged 63,058 sq km for males and 44,936 sq km for females. Straight-line distances from the most distant location on the winter range to the den site averaged 508 km in 1997-1998 and 265 km in 1998-1999 (wolves followed caribou). All but 2 of 15 wolves returned to within 25 km of a previous den, and 2 wolves returned to the same den site.

Dispersing young may move several hundred kilometers. In Minnesota, most dispersers left when they were 11-12 months old; dispersal occurred mainly in February-April and October-November; 35% of known-age wolves remained in their natal territory for more than 2 years (Gese and Mech 1991).

Terrestrial Habitat(s): Alpine, Desert, Forest - Conifer, Forest - Hardwood, Forest - Mixed, Grassland/herbaceous, Savanna, Shrubland/chaparral, Tundra, Woodland - Conifer, Woodland - Hardwood, Woodland - Mixed
Special Habitat Factors: Burrowing in or using soil
Habitat Comments: No particular habitat preference. In Minnesota and Wisconsin, usually occurs in areas with few roads, which increase human access and incompatible land uses (Thiel 1985, Mech et al. 1988, Mech 1989) but apparently can occupy semi-wild lands if ungulate prey are abundant and if not killed by humans (see Mladenoff et al. 1997). Minimum of 10,000-13,000 sq km (with low road density) might be necessary to support a viable population (USFWS 1990); a single pack does not constitute a "minimum viable population" (USFWS 1990). Young are born in an underground burrow that has been abandoned by another mammal or dug by wolf. In Northwest Territories, dens were most commonly located witin 50 km of northern tree line, which resulted in maximal availability of caribou during the denning and pup rearing period; within the tundra zone, dens were not preferentially located near caribou calving grounds (Heard and Williams 1992). In Minnesota, dens usually were not near territory boundaries; den use was traditional in most denning alpha females studied for more than 1 year; possibly the availability of a stable food supply source helped determine den location (Ciucci and Mech 1992).
Adult Food Habits: Carnivore
Immature Food Habits: Carnivore
Food Comments: Predominant prey: ungulates. When these are low or seasonally unavailable, eats alternative prey, such as beaver, snowshoe hare, rodents, and carrion. Commonly hunts in packs, but lone wolves and pairs are able to kill prey as large as adult moose (Thurber and Peterson 1993). In the vicinity of Glacier National Park, feeds primarily on white-tailed deer; sometimes kills mountain lions and sometimes usurps ungulate prey killed by lions (Bangs and Fritts 1993). White-tailed deer and moose carrion were the primary prey in southern Ontario (Forbes and Theberge 1996).
Adult Phenology: Crepuscular, Nocturnal
Immature Phenology: Crepuscular, Nocturnal
Phenology Comments: Mainly nocturnal. In fall-winter in Minnesota, spends most of time sleeping, resting, or traveling, little time feeding (Mech, 1992, J. Mamm. 73:570-571). In south-central Alaska, den site activity was mainly nocturnal; there was a high probability that groups of wolves would be present at the den at midday (Ballard et al., 1991, Can. Field-Nat. 105:497-504).
Length: 205 centimeters
Weight: 40000 grams
Economic Attributes
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Economic Comments: See Gasaway et al. (1983) for information on wolf-prey-human relations in interior Alaska. Wolves sometimes prey on livestock or game ungulates, especially during the wolf denning period. Wolf depredation on livestock increased in the late 1980s and reached a record high level in Minnesota by 1990, and wolf sightings in a designated "no wolf" zone dramatically increased (USFWS 1990; see also Fritts et al. 1992). In recent years the USDA Animal and Plant Health Inspection Service has killed 6-42 wolves annually in livestock-depredation control actions in the northcentral U.S. (USFWS 1990). As of 1990, wolf depredation control was to continue, though possibly limited by funding shortfalls. See Fritts (1982) for information on control of predation on livestock in Minnesota. In Canada, recent annual kill by humans was estimated at 7% of population (Theberge 1991).
Management Summary
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Restoration Potential: Natural recolonization from populations to the north may not be sufficient for restoration of wolf populations in the southern Rocky Mountains. Due to predicted reductions in carrying capacity resulting from development trends and likely landscape change, active reintroduction to two sites within the southern Rocky Mountain region may be necessary to ensure low extinction probability (Carroll et al. (2003).
Management Requirements: See Mladenoff et al. (1997) for a discussion of management related to wolf recovery in the Great Lakes region versus other aspects of biodiversity (e.g., wolves depend on high densities of deer, which can have negative impacts on natural communities and their constituent species). See Cohn (1990) and Matthews and Moseley (1990) for brief discussions of issues related to reintroduction (e.g., compensation for livestock losses, wolf protection status, state vs. federal jursidiction over wolf management). See Fritts et al. (1992) for information on management of wolf-livestock conflicts in Minnesota. See USFWS (1994, Final EIS) and Federal Register (16 August 1994) for an extensive discussion of all issues related to reintroduction in Yellowstone and central Idaho. See Jhala and Giles (1991) for management recommendations for populations in northwestern India. See Theberge (1991) for information on management in Canada.

Limit access of humans and livestock in protected areas.

Population/Occurrence Delineation
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Use Class: Not applicable
Subtype(s): Den
Minimum Criteria for an Occurrence: Evidence of historical presence, or current and likely recurring presence, at a given location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals in appropriate habitat where the species is presumed to be established and breeding.
Separation Barriers: None.
Alternate Separation Procedure: Occurrences generally should be based on major occupied physiographic or ecogeographic units that are separated along areas of relatively low wolf density or use (e.g., major urban areas, very rugged alpine ridges, very wide bodies of water, very sparsely used habitats). These units may be based on available wolf sightings/records or on movements of radio-tagged individuals, or they may be based on the subjective determinations by biologists familiar with wolves and their habitats. Where occupied habitat is exceptionally extensive and continuous, that habitat may be subdivided into multiple contiguous occurrences as long as that does not reduce the occurrence rank (i.e., do not split up an A occurrence into multiple occurrences that would be ranked less than A).
Separation Justification: In the vast majority of the northern part of the species' range in North America, there are few if any true breaks in the distribution.

Gray wolves are highly mobile and readily disperse or migrate hundreds of kilometers (e.g., Walton et al. 2001); populations and metapopulations tend to encompass very large areas (Craighead 1976, Pearson 1975). Hence, meaningful wolf occurrences should represent large occupied landscape units, but these often will not be demographically isolated from other occurrences. Occurrence separations often must be arbitrary.

Inferred Minimum Extent of Habitat Use (when actual extent is unknown): 16 km
Inferred Minimum Extent Justification: This distance is appropriate for much of the southern portion of the wolf's range; based on a home range of 200 square kilometers. In Alaska and northern Canada, distances of 28 to 36 kilometers (representing home ranges of 600 to 1000 square kilometers) are more appropriate.
Date: 29Sep2004
Author: Hammerson, G., and S. Cannings
Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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NatureServe Conservation Status Factors Edition Date: 17Feb2006
NatureServe Conservation Status Factors Author: Qureshi, B., J. D. Reichel, and G. Hammerson
Element Ecology & Life History Edition Date: 21Mar2005
Element Ecology & Life History Author(s): Hammerson, G.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
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