Gray Wolf (Canis lupus) Fact Sheet: Behavior & Ecology

Activity patterns vary

• Predictable patterns observed, though variable across season, between locations, and among individuals (Packard 2003)

Daily patterns

• With pups in summer (Mech and Merrill 1998)
• Daytime: attend pups at den/homesite
• Dusk: depart to forage; typically, though departures also noted at dawn (Harrington and Mech 1982; Mech and Merrill 1998)

Annual patterns

• Late spring to summer (May-Sep):
  • Individuals often travel alone (Fuller et al. 2003)
  • "Stationary" -- activity focused around homesites where pups are raised (Harrington and Mech 1979)
• Late summer to spring (Oct-Apr):
  • Pack individuals regroup (Fuller et al. 2003)
  • Nomadic hunting; pack moves throughout territory (Harrington and Mech 1979)
    • Traveling up to 50 km/day (c. 30 mi/day) (Harrington and Mech 1979)
  • Rarely in the same location more than a few times (Harrington and Mech 1979)

Territory size

• Smaller in areas with higher prey density (Fuller et al. 2003)
• Larger in areas where moose provide the greatest ungulate biomass  (Fuller et al. 2003)
• Range data listed in table below

Extremely social, forming packs

• Cooperatively defend territory
  • Move within exclusive home ranges commonly (Packard 2003)
  • Hostile to outsiders and neighboring packs; some exceptions (Packard 2003)
    • Outsider acceptance by widowed breeder most commonly (Packard 2003)
• Offspring care shared (Packard 2003)

Pack composition (from Mech and Boitani 2003; Mech and Nelson 1990; Packard 2003 unless otherwise noted)

• Regulated by social and physical environmental factors
• Family units
  • Typically 1 breeding male and female with their offspring
  • Polygamous relationships rarely form, occurring in wolf step-families (eg. when a new member immigrates into pack replacing a dead member of the breeding pair)
• Founded by unrelated male and female pair dispersing from natal/birth packs, typically (Packard 2003)
  • Expand if pups are produced
  • Shrink in size as offspring disperse at 10-36 months of age
• Pack size highly variable
  • Range: 2-42 individuals; typically 3-11 (Fuller et al. 2003; Mech and Boitani 2003)
  • Adjusts to food supply and prey biomass within territories (Fuller et al. 2003)
  • Seasonal fluctuation
    • Largest after birth of pups (Fuller et al. 2003)
    • Declines through fall and winter when adult mortality peaks (Fuller et al. 2003)
• Lone individuals common, those dispersing from natal pack (Mech and Boitani 2003; Packard 2003)
  • 10-15% of wolf population in winter (Fuller et al. 2003)

Social structure within packs

• Linear dominance hierarchy, based on behavior and age ranks (Packard 2003)
  • Aggression or submission based social dominance (Mech 1999; Packard 2003)
    • "Alpha" wolf wins all fights within the pack
    • "Beta" loses only to the alpha
    • "Omega" loses all fights within the pack, the least dominant member
  • Age-graded dominance (Packard 2003)
    • Older members dominate younger ones; linear dominance order within each sex
    • Breeding male dominant to the breeding female
  • Most packs have more complex family dynamics and don't strictly align with a single model (Packard 2003)
• Dominant behavior commonly observed; believed to maintain social structure (Packard 2003)
  • Access to food dictated by parents, when present (Packard 2003)
    • Breeders intimidate offspring who demonstrate appeasement/"groveling" behavior (Packard 2003)
    • Order of feeding determined by appeasement gestures and conflict interactions (Packard 2003)
  • Dominant individual pins down or mounts and bites the neck of a subordinate (Harrington and Asa 2003; Mech and Cluff 2010)
• Appeasement behaviors reduce conflict between pack members (Packard 2003)

Leadership within a pack

• Duties of pack leader (Mech 2000b)
  • Initiate daily activity
  • Regulate socialization
  • Initiate, lead, and abort travel and foraging
  • Initiate attacks on prey
  • Provision female and pups with food; female remains with pups for several weeks after birth
• Typically breeding male is leader, influenced by reproductive season, familial relation to leader (step-parentage), and demonstrated hunting success of pack members (Packard 2003)
  • Members often follow breeding male during travel and hunting (Mech 2000b; Packard 2003)
  • In breeding season, the breeding male often remains with his mate at the den site (Mech 2000b)
• Pup care and protection generally initiated and dominated by the breeding female (Mech 2000b)
• Overlap in leadership roles common (Mech 2000b)

Highly territorial (Mech and Boitani 2003)

• Direct and indirect defensive strategies minimize encounters with adjacent packs (Mech and Boitani 2003; Mech et al. 1998)
• Direct encounters with a trespasser may rapidly escalate, often resulting in aggressive chases, injury, and death (Mahrenke 1971; Mech 1993)

Indirect defense

• Maintain visual presence, with widespread and regular travel inside territory in search of prey (Mech and Boitani 2003)
• Howls advertise pack presence across great distances, see description of vocalization below (Harrington and Mech 1979; Mech 1970)
  • Adjacent packs are unlikely to move toward one another during or immediately following inter-pact howling; likely to remain in the same location (Harrington and Mech 1979)
• Scent marks are long lasting (2-3 weeks) indicators of pack presence and structure, see description of behavior below (Mech and Boitani 2003)
  • Encountered c. every 240 meters throughout a territory, concentrated along regularly traveled paths (Mech and Boitani 2003)
  • Rates of scent deposition increase when signs of an outsider are encountered (Peters and Mech 1978)
    • Result in chemically defined boundaries between packs, as with coyotes (Mech and Boitani 2003)
  • Lone-wolf and non-territorial packs do not mark (Mech and Boitani 2003)

Direct defense

• Chase intruders often for considerable distance, > 2 km one observation (Mech 1993; Mech 2000b; Mech and Boitani 2003)
  • Wolves often snap and/or lunge at one another (Mech 1993)
  • Often as a series of advances and retreats (Mech 1993; Mech 2000b; Mech and Boitani 2003)
• Fights occur, though it is unclear why one encounter results in a chase and another in a fight (Mech 1993)
  • Series of attacks and retreats (Mech 1966b; Mech et al. 1998)
  • Commonly result in injury and death (Mech 1993; Mech et al. 1998)
  • Most wolf-killed wolves found near territorial boundaries (Mech et al. 1998)

Facial expressions numerous

Aggressive behavior

• High body posture with slow, deliberate movements (Schenkel 1947)
  • Shortened and wrinkled nose, bared teeth, direct stare
  • Ears erect and forward
  • Tongue retracted
  • Tail held high
• Components of submission and/or play may be associated with aggressive displays (Harrington and Asa 2003)
• Ritualized fighting (Harrington and Asa 2003; Schenkel 1947; Schenkel 1967)
  • Ambush threat: dominant wolf in low, stalking posture
  • Bite threat: dominant stares at rival, teeth bared, forehead and nose wrinkled, ears erect, body tense, and hair raised
  • Defensive snapping: biting the air, often accompanied by barking

Submissive behavior

• Resembles begging and licking behaviors performed by pups to solicit feeding; many variations
• Examples
• Active submission often seen when one wolf approaches another; often in "greeting" or during "group ceremonies" (Harrington and Asa 2003)
  • Submissive approaches dominant with a low posture, slightly crouched, ears back and tail held low (Schenkel 1947; Schenkel 1967)
  • Often wagging tail and hindquarters; anal presentation
  • Attempts to lick or mouth the dominant wolf
• Passive submission often reactionary; following approach and/or investigation by a dominant wolf (Harrington and Asa 2003; Schenkel 1947; Schenkel 1967)
  • Anal withdrawal, submissive tucks tail and lowers hindquarters
  • Lies partly on side and back, tail curved between the legs
  • Ears held flat and directed backward
  • Exposes more of the belly, which is examined further by the dominant

Play

• Wolves mimic or practice hunting skills with fellow pack mates or with novel objects, animals, or plants
  • Stalk or chase (Packard 2003)
  • Ambush and pounce (Mech and Boitani 2003)
  • Face pawing (Packard 2003)
• Other forms of play
  • Tail-pulling, wrestling, keep-away (Mech and Boitani 2003)
  • Bowing, forequarter lowered with hindquarters and tail raised and often wagging (Harrington and Asa 2003; Schenkel 1947; Schenkel 1967)
  • Tail wagging, grinning, head tossing (Packard 2003)
  • Pups playing with novel objects or stimuli, eg. water (Packard 2003)
• Role of play in wolf packs, some hypotheses (Packard 2003)
  • Physical exercise for aerobic conditioning
  • Muscle development and coordination
  • Practice hunting instincts
  • Social bonding

Other

• Group ceremony/rally: mutual muzzle nuzzling, body rubbing, accompanied by whimpering/whining vocalizations (Harrington and Asa 2003; Schenkel 1947; Schenkel 1967)
  • Often occurs prior to pack activities, such as chorus howling or movement away from the current location

Wolf audio provided by Wolf Park and the Cornell Lab of Ornithology Macaulay Library.

Hearing very sensitive

• Detect (likely) sounds up to 26,000 cycles per second, as do domestic dogs (Mech 1970)

4 primary vocalizations (Joslin 1966)

• Howl (summarized by Harrington and Mech 1978)
  • Prolonged (5-11 seconds), deep wailing; shorter and higher pitched in pups
  • Heard across long distances; one estimate of over 4 miles (Mech 1970)
  • Individual howl characteristics may allow wolves to recognize fellow pack members
    • No direct evidence of significant variation in an individual's howl
  • Induces howling by other wolves in the area
  • Howling sessions, chorus of wolves howling, may continue to c.1.5 minutes
    • Daily trends: between dusk and dawn most frequently (also Harrington and Mech 1982)
    • Seasonal trends: adults increasing prior to the breeding season, declining when with young pups (also Harrington and Mech 1979)
  • A call for assembly; after becoming separated, when encountering an abandoned rendezvous site
  • Inter-pact howling may proceed for hours
    • Territorial maintenance; potential to minimize contact between adjacent packs (Harrington and Mech 1979)
    • Adjacent packs are unlikely to move toward one another during or immediately following inter-pact howling; likely to remain in the same location (Harrington and Mech 1979)
• Bark (summarized by Harrington and Mech 1978)
  • Short, explosive sound
  • Meaning unclear; tends to direct attention toward the individual barking
• Whimper(summarized by Harrington and Mech 1978)
  • Associated with decreasing social distance
  • High pitched sometimes fairly soft
  • Performed by adult to pup; pup to adult; adult to adult; wolf to human (when socialized); during chorus howls
    • Greeting or call
    • During courtship
  • Described as whines, squeaks, singing
• Growl (summarized by Harrington and Mech 1978)
  • Deep, coarse sound; 250-1500 Hz, centered around 800 Hz
  • Performed by adults and pups
  • Aggressive display; typically results in increased social distance
    • Threat or warning, assertion of dominance, in defense of food
    • By mothers toward pups to discourage nursing and over exuberant play, or to warn of danger
  • Described as a snarl by some

Strong sense of smell (Mech 1970)

• Important for identifying territorial boundaries, signaling fellow pack members, and identifying prey (Peters and Mech 1978; Rothman and Mech 1979)
  • Used to signal recently hunted areas within territory and to identify nearby pack mates
  • Used to detect upwind prey when within a few hundred yards, distances shorter when prey are downwind

Scent marking

• Raised-leg urination, most frequently deposited scent (Peters and Mech 1978; Rothman and Mech 1979)
  • Small amounts of urine; directed at conspicuous objects (eg. trees, shrubs, rocks, blocks of snow)
  • Primarily on well traveled routes, less common when cutting cross-country
  • Frequency of urination increases before and during the breeding season (Peters and Mech 1978; Rothman and Mech 1979)
  • Pups typically do not scent mark in this way
• Squat urination (Peters and Mech 1978; Rothman and Mech 1979)
• Defecation (Peters and Mech 1978; Rothman and Mech 1979)
  • Placed on prominent objects or locations (eg. stumps, trail junctions, rendezvous sites (pups are left while adults hunt)
  • Contain secretions of anal sacs
• Scratching (Peters and Mech 1978; Rothman and Mech 1979)
  • May release secretions from glands in the paws
  • High ranking wolves most often perform this behavior

Digitigrade

• Walk on the toes (Mech 1970)

Run quickly for long distance (Mech and Boitani 2003)

• Speeds of 56-64 km/hr
• Distances over 72 km/day (43 mi/day) possible
• Legs on same side of body swing in the same line (Mech 1970)

Trott

• Body well suited for this form of motion (Mech 1970)

Swim well

• Distances of 13 km (8 mi) reported (Mech and Boitani 2003) 

Solitary or pack hunters (Sullivan 1978)

• Packs often "test" herds of large prey species, allows wolves to identify injured or straggling individuals (Sullivan 1978)
  • E.g., rushing at a herd of caribou induces individuals to run; healthy caribou are not pursued
• Drive ungulates onto frozen lakes and rivers, into deep snow (Bibikov 1982)

Chase characteristics

• May last for long periods, but often abandoned before capturing prey (Mech 1966a)
• 6 km or less typical
• Reports of chasing/following prey for several kilometers; deer seen chased for c. 21 km by wolves in Minnesota (Mech and Korb 1978)
• Prey standing their ground and those fleeing upslope often not pursued (Bibikov 1982; Mech 1966a)

Attack

• Typically when within 10-200 m (Bibikov 1982; Mech 1970)
• Run head first into large prey, knocking it over (Sullivan 1978)
• Pounce on smaller prey
• Bite nose or neck (Mech 1970; Sullivan 1978)
  • Small prey shaken side-to-side
  • Large prey bitten on the nose; strong canine teeth and jaw muscles hold fast
    • A wolf biting the nose of a large moose was seen lifted off the ground and swung from side to side without being dislodged (Mech 1970)

• Observe and imitate actions of conspecifics/fellow wolves (from Range and Viranyi 2014)
• Apparently better than domestic dogs

Competition (Ballard et al 2003)

• For killed animal
  • Brown bears successfully defend own kill site, usually; wolves are just as likely to maintain their kill as lose it in such encounters (data from multiple sources summarized by Ballard et al. 2003)
  • Black bears unlikely to successfully defend kill site (data from multiple sources summarized by Ballard et al. 2003)
  • Coyotes feeding on wolf kills are chased off and commonly killed (not consumed) by wolves (Ballard et al. 2003)
• For den site
  • Brown bears generally unsuccessful in taking wolf den (data from multiple sources summarized by Ballard et al. 2003)
• For territory
  • Coyote populations expanded with reductions in wolf populations, North America (Ballard et al. 2003)
  • Tigers reported to displace wolf packs, Asia (Ballard et al. 2003 descriptions of others (Gromov and Matyushkin 1974; Yudin 1992))

Commensal relationships

• Scavengers (coyotes, crows, eagles, foxes, and ravens) benefit from feeding on remains of wolf kills (Ballard et al. 2003)
  • Ravens commonly follow wolf packs (Ballard et al. 2003)
  • Communal feeding occasionally observed in winter (Ballard et al. 2003)
    • Wolves, bears, coyotes, foxes, and ravens feeding at the same time on a carcass

Hybridization

• Coyote-wolf hybrids
  • Coywolf detected in wolf populations in some northeastern U.S. states (Nowak 2003)
  • Wolves with coyote-like features, both morphological and genetic
• Wolf-dog hybrids
  • Rare voluntary interbreeding with domestic dogs (Nowak 2003)

Food webs and trophic cascade

• Populations of plants and animals living with wolves are impacted by their presence
• Food webs are representations of feeding/trophic connections between all organisms within an ecosystem
  • Used to visualize relationships between organisms and understand how changes in one relationship may impact others
  • Direct interactions (eg. predator-prey) may have cascading consequences impacting organisms within the larger ecosystem
• Wolves directly impact their prey populations in many ways
  • Prey density often decreases following wolf proliferation and introduction (Mech and Peterson 2003)
  • Health and reproductive capacity of prey herds may increase as wolves preferentially target old, young, and unhealthy individuals (Mech and Peterson 2003)
  • Prey may alter habitat use and foraging behavior within wolf territories (Mech and Peterson 2003)
• Indirect and cascading effects of wolves on ecosystems are unclear (Mech 2012);select supporting studies detailed below (see summaries of all research in Eisenberg et al. 2013)
  • Reductions in the number and density of herbivorous prey may positively impact plant regrowth (Eisenberg et al. 2013)
    • Balsam fir tree growth rates track the pattern of expansion by a local wolf population; trees grew more in years when wolves suppressed moose numbers and indirectly lowered grazing pressure (McLaren and Peterson 1994)
      • Effects more pronounced in areas with higher numbers of wolves
    • Understory plant communities within Wisconsin wolf pack territories show greater species richness (i.e. more species of shrubs and forbs) in comparison to locations outside pack territories (Callan et al. 2013)
  • Altered prey behavior in response to increased predation threat may impact regrowth of vegetation; herbivores spend more time in watch and less time grazing (Eisenberg et al. 2013)
    • Elk in Yellowstone National Park found to avoid riparian areas frequented by wolf packs, releasing aspen trees from grazing pressure and promoting tree propagation and regrowth (Ripple et al. 2001)

Encounters between neighboring packs are generally avoided, as aggression can escalate rapidly and often results in injury or death.

Image credit: © Metassus from Flickr; some rights reserved

Wolf howls can be heard by humans for distances of over 4 miles. Inter-pack howling can last for hours and may play a role in territorial maintenance.

Image credit: © Metassus from Flickr; some rights reserved

Ballard et al. (2003)
Bibikov (1982)
Callan et al. (2013)
Eisenberg et al. (2013)
Fuller et al. (2003)
Harrington and Asa (2003)
Harrington and Mech (1978, 1979, 1982)
Joslin (1966)
Mahrenke (1971)
McLaren and Peterson (1994)
Mech (1966a, 1966b, 1970, 1993, 1999, 2000b, 2012)
Mech and Boitani (2003)
Mech and Cluff (2010)
Mech and Korb (1978)
Mech and Merrill (1998)
Mech and Nelson (1990)
Mech and Peterson (2003)
Mech et al. (1998)
Nowak (2003)
Packard (2003)
Peters and Mech (1978)
Range and Viranyi (2014)
Ripple et al. (2001)
Rothman and Mech (1979)
Schenkel (1947, 1967)
Sullivan (1978)