My own study and thoughts on the abilities of the Grey Wolf (Canis Lupus)
First of all, their diet:
- Potential prey species for the wolves on the Scandinavian peninsula include moose (Alces alces), roe
deer (Capreolus capreolus), beaver (Castor fiber), badger (Meles meles), hare (Lepus europaeus, L.
timidus), capercaillie (Tetrao urogallus), black grouse (Tetrao tetrix) as well as small rodents
(Apodemus spec., Microtus spec., Sciurus spec. etc.) (OLSSON et al. 1997, JOHANSSON 2004). In
Norway the diet can be supplemented regionally with red deer (Cervus elaphus) and wild reindeer
(Rangifer tarandus) (WABAKKEN et al. 2001). The main prey for wolves in Scandinavia is moose and
roe deer (SAND et al. in press). The population densities of the two cervid species have been estimated
by pellet group counts in most of the wolf territories with an average of 0,6 - 2,5 moose/km
Throughout the Scandanavian region Wolves tend to actively prey on the species, with the main prey being Eurasian Elk (Alces Alces) and Roe Deer (Capreolus capreolus).
During the Winter, the Wolves main prey tends to get bigger, and arguably more easier to kill as males start to shed their antlers, and a 100 pound weight loss usually after breeding season in fall.
Wolves may also scavenge on carcasses as well, particularly in Winter during times of scarcity of prey.
- Our study showed that moose is the preferred cervid species on the Scandinavian peninsula, both in
summer and winter. This result contrasts with the statement by MECH (1970), POTVIN et al. (1988),
SPAULDING et al. (1998) und TREMBLAY et al. (2001) that wolves prefer the species that is smaller or
easier to catch if there are 2 or more cervid species available. On an intra specific level this statement
applies to the Scandinavian wolf population, since 80% of all moose killed are calves (PEDERSEN et al.
2005, SAND unpublished data). Concerning the selection of moose and roe deer we seem to face a
different situation in Scandinavia. KUNKEL et al. (2004) argue that the selection of prey takes place on
two levels. Wolves select prey that is easiest to locate and that provides the largest amount of biomass
per successful attack. Both criterions fit for moose in Scandinavia due to the comparatively high
population density and the high biomass per individual
(0,6 – 2,5 individuals per km2
, SAND 2005)
(78kg – 350kg, JOHANSSON 2004, SAND unpublished data). Anyhow large prey species and in
particular moose are dangerous to attack and a wolf might get injured or even killed when attacking a
moose (WEAVER et al. 1992). Nevertheless moose seem to be an easy prey for wolves in Scandinavia.
SAND et al. (2006) state that moose in Scandinavia are currently naive to wolves due to the missing
and low predation pressure when wolves were extinct on the Scandinavian peninsula in the 1960s and
slowly expanded again in the 1980s. The long period of separation of moose and wolves in
Scandinavia apparently caused a loss of an effective anti-predator behaviour, which needs to be
regained now. Because of their inexperience with large carnivores moose on the Scandinavian
peninsula are more vulnerable to wolf attacks than moose in North America (SAND et al.2006).
Another reason for the preference of moose and the avoidance of roe deer in summer and winter
might be the coexistence of wolves with lynx in Scandinavia. MOSHØJ (XXXX) in Sweden and SUNDE
et al. (2000) in Norway describe that roe deer is an important prey for lynx. Hence the prey selection
by wolves might also be explained by food niche separation
A long time without a natural predator can lead to an absence of methods to knowing how to fight them off, clearly demonstrated here.
A ratio of regular Wolf predation on Moose and Roe Deer according to age:
moose => calves : yearlings : adults => 80:10:10
roe deer => fawns : adults => 50:50
In Northern regions, Wolves may prey upon bovines, however, single kills on Musk Ox and sickly Bison have been recorded, however these attempts may lead to death or serious wounds in old wolves:
The single killing of a musk Ox by a wolf, in a fight that lasted 57 minutes, was documented:
Kills by wolf pairs have also been noted:
- The kill we observed took place on Ellesmere Island, Northwest Territories, Canada (80° N, 86°W) on 8 July 1998 when there is continuous daylight. The terrain is barren soil, gravel, rock outcrops and open tundra with no vegetation except widely scattered ground cover. The two Wolves involved were an adult male of unknown origin and a six-year-old female ("Explorer"), which the senior author had habituated to his close presence as a pup around a den in 1992 and studied in 1993 and 1994 (Mech 1995). In 1998, this animal lacked pups, as evidenced by her inconspicuous nipples and nomadic travels.
During the present observations, we used 4-wheeled All Terrain Vehicles to accompany this pair as they traveled and hunted (Mech 1994). We allowed the male to lead, and we paralleled him at distances of 50-100 m, while Explorer remained within a few meters of us; we continually watched ahead for any prey.
At about 0200 on 8 July 1998, the Wolves headed up some foothills along the side of a high escarpment and passed through a valley alongside the ridge. We spotted three Muskoxen about 500 m ahead in a valley at 0224 and immediately stopped and watched through 15X stabilized binoculars. The Wolves continued on toward the Muskoxen, and when about 100 m away, ran straight at them. The Muskoxen fled some 30 m and headed in a tight group up a steep slope, with the two largest animals (one a bull and the other presumably a bull) about half a body length ahead of the smallest, a cow.
As the Muskoxen were running about a third of the way up the slope at 0226, the male Wolf grabbed the last one (a cow) by the rump and hung on, and the female lunged toward the head. The cow wheeled around, and the male lost his grip. Both Wolves focused their attacks on the head and neck of the Muskox, biting at her nose and neck, sometimes hanging on and sometimes losing grip. The Muskox kept pushing up with her lowered head and horns but did not use her hooves. After about 30 seconds of the focused attack, one Wolf gained a solid grip on the cow's nose and the other immediately attacked the side of her neck, repeatedly grabbing a new purchase. The cow appeared to struggle little once the wolves had gained solid grips on her.
The two bulls had stopped about 15 m farther up the hill, and one of them suddenly charged down at the Wolves that were attacking the cow, sending one of the Wolves tumbling about 10 m down the hill. (We could not see whether contact was made, for the bull charged on the opposite side of the cow from us.) The bull hooked repeatedly at the remaining Wolf which eventually released its grip on the cow's nose. By now, the third Muskox had joined the other two, and they headed back up the hill with the cow tightly wedged between the 2 bulls. The Wolves quickly dashed back after the Muskox. Again one of the Wolves grabbed the rump of the cow, which wheeled to meet the wolf head on. The female then grabbed the cow by the nose, and the male by the side of the neck. The wolves kept their grips on the cow for about 30 seconds, and at 0231 the cow fell on a flat area of the hillside about 2/3 toward the top and stopped struggling. The Wolves continued to tear at her head and neck, but the Muskox did not move.
Explorer fed on the Muskox, but the male climbed to the top of the ridge, possibly still wary of us even though we remained about 0.5 km away, and at 0243 he lay down about 20 m above the carcass. Explorer fed on the kill until 0324. She then immediately headed downhill intently searching around as if to begin caching, and went out of sight. At 0340, she passed by us, and we began accompanying her. At 0345, when about 1.5 km from the kill, Explorer dug a hole, regurgitated into it, and covered it. About 50 m away she repeated the behavior. She continued on out of sight at 0349, but the terrain prevented us from following.
At 0413, we saw Explorer about 0.8 km beyond the two caches, returning toward the kill, which she reached at 0441. She then slept near the carcass. Thus she was gone from the carcass for 77 minutes and had traveled at least as far as 2.3 km away from the carcass. From where and when we saw her disappear and reappear, we estimated that she had probably traveled as far as 5 km from the carcass, presumably continuing to cache throughout her trip.
We dug up the two caches and found that their contents of well-chewed, walnut-sized chunks of muscle meat weighed 0.65 and 0.66 kg. A Wolf's stomach can hold 10 kg of meat (Mech unpublished), so if Explorer ate and cached maximally, she could have made about 16 caches of the size we found. Her time and behavior away from the carcass suggests that she did make many caches, but her sleeping and lack of feeding immediately after returning to the carcass suggests that she may have retained at least some of what she had eaten.
We did not observe the Wolves from 0605 to 2150 on 8 July. From 2325 on 8 July to 0003 on 9 July, Explorer again fed on the carcass. Afterwards she alternately slept near the carcass and chased off an Arctic Fox (Alopex lagopus).
From 0251 to 0336, 9 July 1998, Explorer fed once more from the carcass. She then pulled off a front leg and shoulder and carried it off while zig-zagging and looking around as if searching for a place to cache it. She brought the leg to us, and paraded around us a bit. Her abdomen was noticeably distended. After a couple of minutes, she continued on another 600 m to a rocky stream wash and buried the leg in gravel at 0415; only the hoof and ankle were exposed. She continued on in the same direction as when on her previous caching trip, and we lost sight of her again. We did not see her until she arrived back at the carcass at 0541. Her sides were no longer bulging, so apparently she had continued to cache. When we returned to our lookout at 0445, the male was feeding and he continued to do so until 0537, alternately chasing the Fox. Explorer fed again from 0543 to 0559 and lay down about 30 m away from the carcass. We left at 0645.
When we returned at 2130, the Wolves were gone. We then determined that the Muskox was a cow with well-worn teeth and an estimated 25% fat in her femur marrow. This poor condition may explain why the Wolves so readily attacked the cow and killed her so quickly, for often Wolf attacks on Muskoxen are far more prolonged (Gray 1970, 1983, 1987; Mech 1988 and unpublished). We each independently estimated that the amount eaten and cached from the carcass was about 90 kg, which was about all the readily available flesh.
Most Wolf food consumption estimates (summarized by Mech 1970 and by Schmidt and Mech 1997) are made by calculating the weight of edible material taken from a carcass and dividing that by the number of Wolves and days. In this case, the estimate would have been about 22.5 kg/Wolf/day. However, after two of the four feedings we observed, the Wolf cached unknown amounts. If the amount cached were about equal to that digested, then the actual consumption rate would have been only about half the estimate.
How often Wolves cache after killing large animals is unknown, but such caching is not uncommon (Murie 1944, Cowan 1947, Mech 1988, Mech et al. 1998). However, because most observations of Wolf predation are made from aircraft circling around a kill site for short periods, detailed observations such as we relate here are not usually made. Therefore, we suggest that previous food consumption estimates derived as described above may have to be qualified to account for possible caching that went undetected. In particular, conclusions derived from observations over intervals of a few days could be greatly inflated. We also suggest that future research emphasize attempting to determine how commonly Wolves cache after killing large animals, and under what circumstances.
Next, hunting methods in North America:
- Wolves hunt in a pack structure, often overrunning larger prey (such as deer, elk
or moose in Minnesota) and taking it down as a group. The wolf pack will often single
out a weaker member of a herd, such as an older animal or younger animal and section
that animal off away from the rest of the herd. Then they will basically run that animal
down until it can be taken by the pack. Biologists have estimated that less than 10% of all
wolf attacks on large animals are successful, this has been listed as one reason that
wolves will single out weaker members of the heard – to hedge their bets a little. Wolves
have also been known to eat smaller prey, such as rabbits, beavers, small rodents and
even fish when they can’t get sufficient amount of the larger prey. In Minnesota the wolf
Minnesota State University Moorhead –Natural History of the Gray Wolf.
- The United States Fish and Wildlife Service.
population is highly dependant upon deer – of which is takes approximately twenty deer
per year per wolf to keep the wolf healthy.
Grey Wolves are common predators of young moose and elk, simutaneously distracting the mother and leaving a single member to grab the forty pound calf and run off with it.
These animals have often costed significant loss in farm area:
- Since 1987 total confirmed minimum livestock
losses in NW Montana totaled 82 cattle, 68 sheep, 7
dogs, and 2 llamas. Depredations averaged 6 cattle, 5
sheep, and less than 1 dog annually. Agency control
killed about 3 wolves a year. On average, less than
6% of the wolf population is annually affected by
agency wolf control actions (Bangs et al. 1995).
Minimum confirmed livestock losses have annually
averaged about 4 cattle, 28 sheep, and 4 dogs in the
Yellowstone area and 10 cattle, 30 sheep, and 2 dogs
in central Idaho. In addition, 1 newborn horse and
probably 3 adult horses were killed in the Yellowstone area. In total there have been 148 cattle, 356
sheep and 37 dogs confirmed killed by wolves from
1987 until January 2001. Since 1987, the Service and
USDA Wildlife Services have relocated or killed,
respectively, 32 and 41 wolves in NW Montana, 33
and 18 in central Idaho, 34 and 26 in the Yellowstone area, because of conflicts with livestock.
Wolves are removed by leg-hold trapping, neck snaring, and darting or shooting from the ground or air.
With prey size, Wolf hunting and killing methods tend to differ. With large prey, mature wolves usually avoid attacking frontally, instead focusing on the rear and sides of the animal. With Moose and Elk, it is often eliminated by biting chunks of flesh from the perinial region, causing often large and painful bleeding wounds and sometimes measuring up 17cm, with three well placed snares sufficient enough to bring even a healthy Eurasian Elk down, and tight holds to the hind-quarters may also be a common killing practice among more experienced wolves.
With moderate-sized prey, Wolves tend to kill by a throat hold, killing the animal by severing arteries and nerve tracks, often crushing the trachea and/or the carotid artery. This causes internal bleeding wounds and typically causes the animal to die within a few seconds, too one or two minutes.
With smaller prey, round about the size of a rat or rodent, in typical canid fashion it will leap up above the ground and attempt to flinch and paralyze the prey using their forepaws.
When facing other carnivores in their sympatric regions, they will usually kill them by either a skull bite, often penetrating and breaking the skull, or a neck bite, crushing the windpipe.
At the time, Garwood suspected that the cougar was searching for a new home range when it came across the dogs.
- A necropsy on the cougar showed no malnourishment. It had elk hair in its stomach and healthy fat reserves.
"It was living pretty well," Garwood said.
The investigation also proved the extent of the predator's injuries. Garwood said numerous puncture marks were visible on the cat's hindquarters and on its back all the way through to the spinal cord. But it was two deep bite marks on the cat's neck that were likely fatal, he said.
Enemies and competitors:
Lynx: Few interactions between lynx and wolves have been documented in North America. Erkki Pulliainen, a researcher at the Univeristy of Helsinki, found that wolves and lynx in Finland seem to be enemies and that they do not share territories. In Hungary and Finland, lynx numbers tend to increase in an area when wolf numbers in that area decrease.
Coyotes: Wolves will often chase away (and possibly kill and eat) coyotes that venture onto their territory. When wolves were reestablished in Yellow- stone National Park, coyote numbers in the park decreased and coyotes disappeared on Isle Royale about eight years after wolves reached the island. Some studies, such as those done by coyote biologist Wendy Arjo, suggest that coyotes often avoid wolves and choose home ranges that lie between the ranges of wolf packs. Coyotes are also active between the hours of 7:00 am and 11:00 am, while wolves are generally active at night. However, some coyotes will scanvenge off of wolf kills and some will even follow a wolf pack from a distance so they can scavenge off of the wolf kills when the wolves are some distance from it. The two species can interbreed, though they rarely do so. However, there is some evidence that the two species have interbred with each other in the eastern United States. Interbreeding between the two species is most likely to occur when wolf numbers are so low that a lone wolf would have a great deal of trouble finding a mate of the same species. Coyotes have also been breeding with the endangered red wolf.
Wolves are very protective of their kills, and will mostly chase Coyotes of them should they be discovered scavenging the kill, although some Wolves will actively pursue and kill the Coyote to remove the animal from presence, this is very common in situations in times of food scarcity.
Black Bear: The American Black Bear is a more averse animal than it's close cousin, the Grizzly Bear along with being smaller, naturally they will be more willing to give up a kill or carcass to a wolf pack than a Brown Bear, and more likely to be killed at that.
- INTERACTIONS OF WOLVES AND BLACK BEARS
IN NORTHEASTERN MINNESOTA
Wolves (Canis lupus) and black bears (Ursus americanus) were sympatric throughout much of their
former ranges in North America and still co-inhabit large parts of Canada, Alaska, and Minnesota (Hall and
Kelson, 1959; Mech, 1970).
However, the only published records of interactions between them are a
trapper's description of wolves killing a black bear of unknown age and sex (Young and Goldman, 1944)
and a report by Joslin (1966) of a black bear killing an adult female wolf near a den of pups. In addition, C.
C. Dickson (pers. comm.) found that wolves killed an immature black bear in northern Ontario on 18 May
1979. We now report on interactions between wolves and bears observed during concurrent telemetry
studies of both species in northeastern Minnesota between 1969 and 1979 (Rogers, 1977; Mech, 1979).
Territories of wolves and bears commonly overlapped in this area.
On 16 June 1972, a radio-tagged, 11-year-old female bear was observed from the air as she walked
toward an adult wolf lying in a grassy opening. The bear was in her territory, and the May 1981 GENERAL NOTES 435
wolf was less than 100 m from an area of well-worn beaver (Castor canadensis) trails that wolves
frequented. With approximately 30 m separating the two animals, the bear suddenly ran toward the wolf,
which sprang up and was pursued vigorously in circles and zig-zags for approximately 25 s before it
escaped into dense streamside brush. The bear walked back in the direction from which she came. On 18
September of that year, the same female bear remained at her bedsite while a wolf pack howled repeatedly
within 250 m of her. During the next 4 days, she constructed her den less than 300 m from a rendezvous
site that was in constant use by the wolf pack.
On 23 May 1973, a radio-tagged, 6-year-old female bear was observed from the air 6 m up in a tree 25
to 50 m from an active wolf den. At least one yearling wolf lay about 10 m from the tree facing the bear.
The 58 to 62 kg bear was within her territory.
On 12 June 1973, a wolf approached to within 5 m of a tree in which a bear had left her cubs while she
fed in a garbage pit 25 m away. The mother immediately ran from the pit and closely pursued the wolf for
30 to 50 m. On another occasion at the garbage pit (12 August 1976), four wolves approached but did not
enter the pit where two adult bears fed. Two subadult bears sparred playfully near the pit and within 10 m
of an adult wolf. Suddenly, one of the subadult bears stopped sparring and pursued the wolf 30 m to forest
cover. The wolf reappeared shortly but was not chased again even though it approached to within 10 or 15
miles of the sparring bears. Two or three more bears arrived, and the wolves left.
Of 206 occupied bear dens examined one to eight times each, only two showed signs of being visited by
wolves. Additional sign possibly was covered by snow. Dens differed in characteristics from secure caves
or burrows to nests constructed above ground. In one of the two visits, tracks indicated that a wolf pack
gathered at the den of a radio-collared, 5-year-old female on 10 November 1970. Her den was a 2-m deep
burrow under a stump and had a single entrance that seemed barely large enough for the 43-kg bear to
enter. The bear was shot in the abdomen 5 months earlier and died of her injuries about 24 November.
However, the bear was still vigorous at the time of the visit (as evidenced by her subsequent travels), and
there was no sign of physical contact between the bear and the wolves.
In the remaining instance of wolves visiting a bear den, a wolf pack that included radio-collared
members killed a radio-collared, 16-year-old female bear and her newborn cubs on 17 or 18 February 1977.
The wolf pack was known to consist of nine members, although only six were seen from the air on 18
February when the pack was resting near the partially eaten carcass. The bear's weight at the time of the
attack was about 72 kg. Her den site, a shallow depression under five logs 10 to 30 cm in diameter,
afforded her no protection on either side. Only 35 cm of snow had accumulated by 18 February, and the
unusually light snowfall did not cover the den as it would have in most winters.
Analyses of a photograph taken from a plane on 18 February and sign observed at the site on 21 March
1977 provided evidence of the interaction. The wolves apparently attacked from both sides and drove the
bear from the den. The bear fought her way 22 m to the nearest big tree, a mature aspen (Populus
tremuloides), leaving a path of broken brush and bear fur. At the tree, the fight continued; trampled brush,
part of a wolf canine tooth, tufts of wolf fur, and much bear fur were concentrated in a 3-m radius around
the tree. The bear possibly was injured as there were drops of blood on the tree, but claw marks indicated
that she climbed to the safety of the crown.
She eventually came down and returned to the den where she
died or was killed. Bear fur covered the snow within 2 or 3 m of the den. Tracks visible in the photographs
showed that the wolves dragged the carcass beyond the fur-covered area to consume it. By 21 March, all
that remained of the carcass was fur, fragments of bone, and the nearly intact skull. Wolf droppings in the
vicinity contained claws of the newborn cubs.
The death of this family was the only known predation loss to occur during 206 bear-years of radiotracking bears 1 year of age or older (Rogers, in press). This interaction occurred after a decline in the
primary prey of the wolf in Minnesota, the white-tailed deer (Odocoileus virginianus) (Mech and Karns,
1977). The wolf pack was trespassing in another pack's territory when it killed the bear.
Only 19 (1.3%) of 1,475 wolf droppings collected by Byman (1972) and Frenzel (1974) during
snowfree periods in northeastern Minnesota contained bear remains.
Cougar: Wolves will sometimes drive a cougar away from a kill it has made so they can eat it themselves. A solitary cougar is often at a disadvantage when it is involved in a fight with a wolf pack, but a cougar may injure and/or kill wolves that try to take over a kill it has made if there are only a few wolves present. Both are generally an equal match for each other, and will make an effort to avoid a frontal confrontation. It is rare for a wolf to kill a mature cougar, but it has happened and wolves occasionally kill cougar cubs. Overall, wolf-cougar interactions are rarely observed because of the rarity of the two species, but the two generally share an animosity towards each other, since they both prey on large game.
Cougars generally kill young or female wolves by ambush, but may do the same to young males:
- 95 and 1996, 35 Wolves were relocated from
British Columbia and Alberta, Canada, to the Frank
Church Wilderness Area in Central Idaho. Wolf #B-4,
an adult female Wolf captured on 10 January 1995 at
Petit Lake, Alberta, was released on 14 January 1995 in
the Corn Creek drainage near Salmon, Idaho.
By the end of February 1995, Wolf B-4 was located near the
town of Drummond, Montana, approximately 185 km
from the release site. Radio contact was lost on 17 No -
vember 1995, but we picked up a mortality signal in
mid-January 1996 in that same vicinity.
Wolf was buried under approximately 60 cm of hardpacked snow in mountainous terrain covered by dense
timber. We sent the frozen Wolf carcass to the U.S.
Fish and Wildlife Service Forensics Lab in Ashland,
Oregon. A necropsy revealed head trauma and a puncture from a canine tooth through the top of the Wolf’s
skull. The Wolf had been killed, but not fed on, by a
Cougar. From the time B-4 was released in 1995 until
her death in 1996, we saw the Wolf one time and she
was traveling alone.
On 29 January 2003, the radio-collar of female Wolf
#297f from the Mill Creek Pack was located on mortality mode in the Paradise Valley, north of Gardiner,
Montana. The pack consisted of three adults and four
Investigation the following day found
tracks of two Wolves traveling in 15-20 cm of snow
along a two-track road in a mixed conifer forest. A
barbed wire fence paralleled the road with briar bushes
grown into it. Considerable amounts of Wolf hair and
blood were found on the fence and on a bush. Tracks
in the snow indicated that two Wolves were walking
down the road but then both began to run.
One set of
Wolf tracks veered into the timber. The second set
went through the barbed wire fence where the blood
and hair were found. Drag marks in the snow led to a
pile of 10 cm deep needles that covered the dead Wolf.
Tracks indicated an adult Cougar with one or possibly two kittens had fed on the Wolf carcass. Punctures
in the Wolf’s hide and massive hemorrhaging were
found on the neck and trachea.
It was unknown if capture and handling twelve days earlier hindered the
Wolf’s ﬂight, but we suspect that the Wolf running
through the fence contributed to the Cougar catching
and killing it.
A young, healthy, male Wolf #SR1 was ﬁtted with
an Argos satellite collar 18 November 2005 west of
Turner Valley, Alberta, Canada. Wolf #SR1 appeared to
be moving normally following capture until late February when daily locations localized in a 10 km2
On 16 March 2006, Fish and Wildlife staff investigated the area and located the remains of #SR1 which
included all four legs, head, tail, intestines, and stomGray Wolves, Canis lupus, Killed by Cougars, Puma concolor, and a
Grizzly Bear, Ursus arctos, in Montana, Alberta, and Wyoming
Four cases where large predators caused Grey Wolf (Canis lupus) mortality are recorded. We describe two incidents of
Cougars (Puma concolar) killing Wolves in Montana and one incident of a Cougar killing a Wolf in Alberta. We report the
ﬁrst recorded incident of a Grizzly Bear (Ursus arctos) killing a Wolf in the western United States.
Wolves do kill female cougars of similar size
Wolverine: Interactions between wolves and weasels are typically of an aggressive nature. Wolverines, while sometimes known to run Wolves off kills, are still often driven away from a kill they have been feeding on by wolves. Occasionally, the wolverine is killed. Martens, mink and ermines are often killed by wolves, and their carcasses are usually left uneaten. Despite this danger, weasels often scavenge off of abandoned wolf kills.
Red Fox: Foxes, like coyotes, weasels, and bears, will scavenge off of wolf kills. Many other species also rely somewhat on food gained from wolf kills. These include eagles, gulls, grey jays, blue jays, stellar's jays, red squirrels, deer mice, black-capped chickadees, boreal chickadees, and bobcats. Wolves will sometimes raid food caches that a fox has prepared, and wolves will also take over old fox dens. Wolves often ignore foxes, since foxes do not compete with wolves for food as foxes hunt much smaller animals than wolves do. However, wolves will chase away, and possibly catch, injure and kill, a fox that was caught feeding on its kill. Most foxes are fast and alert enough to get away from the wolves first. Although it is rare, wolves have been known to prey on red foxes. Arctic wolves will also prey on arctic foxes if food is scarce.
Raven: Common Raven are often sighted near Wolf kills and territory and are generally impervious to wolf predation, as they have feathers and act aggressively towards lunges. They may help Wolves by finding carcasses for the canids to feed on, and getting tolerated by the pack in the process. These are the only predator in the area mostly tolerated by Wolf packs.
Brown Bear: Wolves and bears can coexist peacefully and often avoid each other. However, wolf-bear interactions can be quite violent. Grizzly bears will sometimes dig up, kill, and eat wolf pups. As a result, wolf packs will attempt to drive away grizzly bears that get close to the dens where wolf pups are living. Wolves may even attack, and have been known to kill, a grizzly bear that gets too close to the den. Wolves and grizzly bears have been seen fighting over animal carcasses from helicopters in Alaska. Bears will scavenge off of kills made by wolves, and they may try to drive a wolf or a few wolves off of a kill. Wolves can be quite aggressive towards black bears. There are records of wolves preying on black bears, and wolves have been known to kill and eat hibernating bears. Wolves will also attack black bear cubs when the mother bear cannot get to them and hurry them up a tree fast enough. Black bears will also occasionally kill wolf cubs.
Interactions between Wolves and Female Grizzlies with cubs.
- From 1995 through 2002, 96 wolf-grizzly interac-
tions were recorded (Ballard et al. 2003, D. Smith,
unpublished data). Only 8 (8%) of these interactions
were between wolves and female grizzly bears with cubs
(Fig. 1). Females with older offspring were also rarely
observed interacting with wolves. Only 7 (7%) inter-
actions between wolves and females with yearlings or
two-year olds were recorded.
Of the 8 interactions between wolves and female
grizzly bears with cubs, 5 were at carcasses, 2 were at
wolf rendezvous sites, and 1 occurred at a neutral site. In
3 of the 5 interactions at carcasses (Observations 1, 5, 8;
Table 1), the bear family groups were displaced by
wolves regardless of the number of wolves present (1-5
wolves). In 1 of these interactions (Observation 1; Table
1), a larger bear, probably a male, was feeding on the
carcass before the female with cubs approached. After
the lone bear left the carcass, a wolf fed on the carcass
and the female with cubs left the area. The outcome of 1
interaction near a carcass was neutral (Observation 2;
Table 1; Fig. 1). A female grizzly with 2 cubs
encountered 4 adult wolves that were walking away
from the carcass of a bull elk that was being controlled
by a single grizzly bear. After a brief standoff, the
wolves continued walking away from the carcass and
the female with cubs continued walking toward the
carcass. Although the interaction with the wolves was
neutral, the female with cubs did not attempt to usurp the
carcass from the single adult bear.
In the other interaction at a carcass (Observation 3,
Table 1), a female with 2 cubs successfully usurped
a carcass from 6 wolves. On 17 June 2001 at 0606
hours, 6 members of the Druid Peak pack were observed
in Lamar Valley feeding on the carcass of a cow elk they
had probably killed the previous night. The 6 pack
members present included radiomarked wolves 21 (the
alpha male) and adults 106F, 217F, and 224M, as well
as two unmarked yearlings. The remaining 20 adult and
yearling wolves of the pack were not at the carcass, nor
were the 11 pups from two litters. At 0614 hours, an
adult female grizzly bear with 2 cubs was observed
approaching the carcass from the west. When the bears
neared the carcass, the wolves circled and confronted
them. As the bears faced wolves that were directly in
front of them, other wolves rushed in and bit at the bears
from behind. The cubs stayed directly beside or beneath
their mother as she slowly continued toward the carcass.
Periodically, the female stopped to protect herself and
lunged and swatted at the wolves. At times all 3 bears
lunged together at an approaching wolf; other times the
adult or cubs lunged independently at approaching
Several times the wolves completely stopped the
bears' progress toward the carcass as the bears whirled
around to face the circling wolves. The bears took
approximately 20 minutes to move the final 100 meters
to the carcass. At 0646 hours the bears reached the kill
and began to scavenge. The wolves continued to circle
the scavenging bears, but only occasionally rushed and
harassed them. At 0734 hours, after feeding on the
carcass for about 48 minutes, the bears left the kill and
walked away to the southwest. The wolves did not
harass the bears as they left. None of the bears was hurt.
Two encounters between wolves and female grizzly
bears with cubs were observed at wolf rendezvous sites.
In late July 2002 (Observation 6, Table 1), 5 adult
wolves and 3 wolf pups were at their rendezvous site
when a female grizzly with 3 cubs walked through the
site. One wolf approached the bears and followed them
out of the area and no further interactions ensued. One
week (Observation 7, Table 1) later, the same 4 bears
walked through the same wolf rendezvous site when
only the 3 wolf pups were present. The pups fled the
area upon sighting the bears; the bears left the area with
no visible response to the pups.
One other interaction between wolves and a female
grizzly bear with cubs did not involve a carcass or
rendezvous site (Observation 4, Table 1). A female with
2 cubs was walking within 1 km of a wolf den site when
2 wolves approached her. The adult bear charged at the
wolves. The wolves stopped their approach and retreated
but did not leave the area. The female and cubs left the
area, and no other interaction was recorded.
(Mammals of the Soviet Union, 1989, pg 174, 175)
Wolves an excess of 90kg are rare, but not an impossibility in Eastern Europe, where they are assumed to reach extremely large sizes, the conventional methods used for determining the size, however is yet unknown.
Wolves overall size tends to substantially increase due to Bergmann's Rule, often having Russian, North American, and European wolves weighing much more than their Middle Eastern and Asian cousins. This rule does not apply in polar regions, where the wolf subspecies there, Arctic Wolves ( Canis Lupus arctos) which inhabits the Canadian Arctic, subsequent islands, and parts of Russia and Greenland is somewhat smaller than the other northern wolves, due primarily to the prey scarcity in the region, and permafrost soil, making it hard for Wolves to travel and kill prey, often leaving them malnourished or thin.
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