U.S. Fish & Wildlife Service

Gray wolfCanis lupus

Gray wolves have evoked a variety ofresponses from humans throughouthistory. Most Native Americansrevered gray wolves, trying to emulatetheir cunning hunting abilities.However, wolves became nearly extinctin the lower 48 states in the early part ofthe 20th Century because settlersbelieved wolves caused widespreadlivestock losses. Constantly persecutedand targeted by predator eradicationprograms sponsored by the Federalgovernment, wolves have been pursuedwith more passion and determinationthan any other animal in U.S. history. Bythe time wolves were finally protectedby the Endangered Species Act of 1973,they had been exterminated from thelower 48 states except for a few hundredinhabiting extreme northeasternMinnesota and a small number on IsleRoyale, Michigan.

Second only to humans in their adapta-tion to climate extremes, gray wolveswere equally at home in the deserts ofIsrael, the deciduous forests ofWisconsin, and the frozen arctic ofSiberia. Within the continental UnitedStates, gray wolves once ranged fromcoast to coast and from Canada toMexico, but they were absent from areasof the Southeast and East that wereoccupied by red wolves (Canis rufus).

Wolf groups, or packs, usually consist ofa set of parents (alpha pair), theiroffspring, and other non-breeding adults.Wolves begin mating when they are 2 to3 years old, sometimes establishinglifelong mates. Wolves usually reartheir pups in dens for the first 6 weeks.Dens are often used year after year, butwolves may also dig new dens or usesome other type of shelter, such as acave. An average of five pups are born inearly spring and are cared for by theentire pack. They depend on theirmother’s milk for the first month, thenthey are gradually weaned and fedregurgitated meat brought by other packmembers. By 7 to 8 months of age, when

they are almost fully grown, the pupsbegin traveling with the adults. Often,after 1 or 2 years of age, a young wolfleaves and tries to find a mate and formits own pack. Lone dispersing wolveshave traveled as far as 500 miles insearch of a new home.

Wolf packs usually live within a specificterritory. Territories range in size from50 square miles to more than 1000square miles depending on how muchprey is available and seasonal preymovements. Packs use a traditionalarea and defend it from strange wolves.Their ability to travel over large areasto seek out vulnerable prey makeswolves good hunters. Wolves may travelas far as 30 miles in a day. Although theyusually trot along at 5 m.p.h., wolves canattain speed as high as 45 m.p.h. for shortdistances.Indirectly, wolves support a wide variety

of other animals. Ravens, foxes,wolverines, vultures and even bears feedon the carcasses of animals killed bywolves. In some areas, bald eaglesroutinely feed on the carcasses ofanimals killed by wolves during thewinter. Antelope are swift, elk are alert,and mountain goats can climb steepcliffs, in part, because of the long-termeffects of wolf predation. Wolves alsohelp regulate the balance between theseungulates (hoofed animals) and theirfood supply, making room for smallerplant-eaters such as beavers and smallrodents.

Wolves are noted for their distinctivehowl, which they use as a form ofcommunication. Biologists haveidentified a few of the reasons wolveshowl: before and after a hunt, to soundan alarm, and to locate other members ofthe pack when separated. Wolves howl

Western settlers believed that the graywolf caused widespread livestock losses,leading to the wolf’s near extinction in thelower 48 states in the early part of the 20th

century. Under predator control pro-grams, wolves were hunted and killedwith more passion and zeal than anyother animal in U.S. history.

more frequently in the evening and earlymorning, especially during winterbreeding and pup-rearing. Howling isalso one way that packs warn otherwolves to stay out of their territory.

Early settlers moving westwardseverely depleted most populations ofbison, deer, elk, and moose – animalsthat were important prey for wolves.With little alternative, wolves turned tosheep and cattle that had replaced theirnatural prey. To protect livestock,ranchers and government agenciesbegan a campaign to eliminate wolves.Bounty programs initiated in the 19th

Century continued as late as 1965,offering $20 to $50 per wolf. Wolveswere trapped, shot from planes andsnowmobiles, dug from their dens, andhunted with dogs. Animal carcassessalted with strychnine were left out forwolves to eat. This practice alsoindiscriminately killed eagles, ravens,foxes, bears and other animals that fedon the poisoned carrion.

Today about 2,445 wolves live in the wildin Minnesota, fewer than 20 on LakeSuperior’s Isle Royale, about 278 inMichigan’s Upper Peninsula, 323 inWisconsin, and about 664 in the northernRocky Mountains of Montana, Idaho, andWyoming. Wolves are being reintro-duced to Arizona and New Mexico. Anoccasional wolf is seen in WashingtonState, North Dakota, or South Dakota.Populations fluctuate with foodavailability, strife within packs, anddisease. In some areas, wolf populationsalso may change due to accidental andintentional killing by people.

Gray wolves are listed under theEndangered Species Act as endangeredin the southwest and as threatenedelsewhere in the lower 48 states withintheir historical range. Endangeredmeans a species is considered in dangerof extinction throughout all or a signifi-cant portion of its range, and threatenedmeans a species may becomeendangered in the foreseeable future. InAlaska wolf populations number 5,900 to7,200 and are not considered endangeredor threatened.

Wolf recovery under the EndangeredSpecies Act has been so successful thatin 2003, the U.S. Fish and WildlifeService reclassified wolves fromendangered to threatened throughout a

large portion of their historical range inthe coterminous United States. Thewolf’s comeback has been attributed to acombination of scientific research,increased protection, reintroduction andmanagement programs, and educationefforts that helped increase publicunderstanding of wolves.

Successful reintroduction andmanagement programs have acceleratedwolf recovery in the Rocky Mountains.Gray wolves have expanded theirnumbers thanks to science-based wolfmanagement; restoration of wolf preyspecies such as deer, elk, and moose; andlegal protection.

In Minnesota, home of the largest wolfpopulation in the lower 48 states, a stateprogram provides compensation forlivestock confirmed to be killed bywolves, and a Federal program conductstrapping of individual wolves that preyon domestic animals. Similarcompensation and trapping programsexist in Wisconsin and Michigan. In theWest and Southwest, a private compen-sation program run by the Defenders ofWildlife pays for livestock killed bywolves.

Wolf recovery and management are verypolarized, controversial, and emotionalissues stemming from people’s attitudes,fears, and misunderstandings more thanfrom wolves themselves. Attitudes areoften based on inaccurate information,making wolf management perhaps moredifficult than any other wildlifemanagement program.

Some people fear that if wolves are in anarea, outdoor activities will berestricted or they fear that wolves willattack people. However, wolves aretolerant of human activity but generallyavoid getting too close to humans. It isusually not necessary to restrict outdooractivities, such as logging, mining, oroutdoor recreation, to protect wolves.Also, wolf attacks on humans are rare inNorth America. Most documentedattacks have been in areas where wolvesbecame habituated to humans when theywere hand fed or attracted to garbage.

For the past 22 years, YellowstoneNational Park has been at the center ofdebate over the wolf. By about 1930,wolves had been deliberately extirpatedfrom the western United States,

including Yellowstone. After years ofcomprehensive study and planning, theU.S. Fish and Wildlife Servicereintroduced gray wolves intoYellowstone and U.S. Forest Servicelands in central Idaho. In 1995 and 1996,31 wolves from Canada were released inYellowstone National Park. At the sametime, 35 wolves were released onremote Forest Service lands in Idaho.All of the reintroduced wolves werefitted with radio collars and monitoredby biologists from the Fish and WildlifeService and other cooperating agencies.The reintroduction has been verysuccessful, and by December 2002 therewere about 560 wolves in theYellowstone area and Idaho.

The Yellowstone and Idaho wolves aredesignated as non-essential,experimental populations under theEndangered Species Act. Thisdesignation allows Federal, State, andTribal agencies and private citizensmore flexibility in managing thesepopulations. Wolves that prey onlivestock will be removed and, ifnecessary, destroyed. Ranchers may killwolves they catch in the act of preying ontheir livestock on private lands. Theymay be issued a permit to do the same onpublic lands after certain conditions aremet. The experimental program hasworked so well in the northern Rockiesthat a similar effort is being used torestore Mexican wolves to theirhistorical range in the southwesternUnited States.

Mexican gray wolves, which onceinhabited the southwest, existedrecently only in zoos until 1998 when 13wolves were released in Arizona. Todate, 74 wolves have been released inArizona and New Mexico. In 2002, atleast 21 wolves remain in the wild withanother 241 in zoos and other facilities.For the first time, four wolf packsproduced pups in the wild in 2002. Thegoal is to establish a self-sustaining wildpopulations of at least 100 wolves in thespecies’ historical range.

Wolf recovery efforts represent anopportunity to redress past mistakes inwildlife management and enhance ourunderstanding not only of wolves, butalso the complex interactions amongspecies in their natural environments.

Revised March 2003