Among Wolves: Gordon Haber's Insights into Alaska's Most Misunderstood Animal

by Haber, Gordon

  Wolves are master hunters, but by no means are they able to take down ungulate prey at will. They encounter many moose, sheep, caribou, and other species before finding vulnerable individuals. Wolves must rely on sophisticated cooperative pursuit, testing, and killing tactics because of the difficulty and danger posed by physically superior prey. They also depend much more heavily on winter kill than has been generally realized. In a sample of 2,666 miles of their travels over a series of mild, severe, and average winters, Savage River and Toklat killed moose in only about 5 percent of all encounters. When encountering herds of sheep, they were able to kill one about 25 percent of the time. And for all caribou herd encounters, they caught one about 45 percent of the time. They also scavenged rather than killed about three-quarters of the moose they ate and about half of all the moose, caribou, and sheep they ate combined. Experienced wolves are generally able to kill or scavenge something every few days in winter.

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  June 26, 2009

  In some meadows the yellow cinquefoils and pink wild roses are really out in profusion. Later I will stop to eat the juicy yummy rose hips.

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  Hunting Traditions

  Traditions develop as successive generations continue to pass on their accumulated learning, enriching and updating it with current information regarding prey resources and local conditions. Each wolf family group develops its own unique adaptive twists and in the process becomes increasingly tuned to local conditions. For example, the Savage River family group specialized in prey driving and ambushing techniques that were effective in hunting the relatively abundant moose and sheep of its territory, and the Toklats used a decoy technique well suited for hunting caribou. The collection of traditions within and between family groups amounts to the formation of culture, and wolves are easily among the most cultural of all nonhuman animals.

  Wolves respond to differing winter foraging circumstances across three large areas of Denali National Park. In the eastern area, where the Savage River and Toklat families lived, the wolves remain primarily within year-round territories where they are able to hunt sheep as well as moose after most caribou leave. In the central area where there are no sheep and lower moose densities, they migrate northeastward with caribou, resulting in high competition and strife with the year-round northeastern residents and other migrant groups, and increased likelihood of deaths by trapping and hunting. Even in the eastern area there were differences in food resources. The Savage River family group had a more consistent food base year-round, independent of caribou herd fluctuations, with a higher density of moose. The Toklat, on the other hand, were more dependent on the caribou, and thus more affected by herd population levels and by the seasonal migratory patterns.

  As caribou populations dropped, the Toklats responded with changes in the very social structure of the group. Several decades ago when Toklat was still afforded a summer abundance of caribou within a larger territory, it featured a loose, often multiple-family social structure with frequent temporary even-aged winter splitting. Now, with low caribou numbers across the region year-round, Toklat still maintains about the same group size, with heavier dependence on lower but seasonally more stable numbers of moose and sheep—substantially within the old Savage River territory—and with a tighter, more Savage-like social structure in which there is virtually no winter splitting.

  The basic searching routine of experienced wolves is to keep moving, testing as many prey as possible, checking out most major prey areas of the territory on average once every few weeks in winter. It usually doesn't pay to persist with the same prey for long periods. The outcome is commonly determined in the first few minutes and most energy expended once the prey is alert is largely wasted.

  The wolves don't travel regular circuits, but by the end of winter will have searched most of the nooks and crannies of their large, mountainous territories and tested most prey at least once, thereby identifying and culling most of the weakest prey. Inexperienced wolves, in contrast, linger for longer periods with the same prey, cover much less ground, and therefore get much less to eat.

  The learned cooperative hunting I've observed includes strategies that are widely used by many different family groups, such as “nose-to-hind-end” moose killing, coordinated distant setup and pursuit, driving prey into difficult escape terrain, and mineral-lick ambushing. Other tactics were apparently developed and used by only one group, effectively becoming family traditions. I observed unique hunting techniques for both the Toklat and Savage River family groups, both of which had the longevity required to develop hunting to fit their environments. Two techniques that were unique to the Savage River family group were the storm-and-circle testing for moose and the chase-to-alpha ambush for sheep. For the Toklats, the two predominant and unique hunting techniques used are a decoy technique well suited for hunting caribou and a waiting technique effective on sheep. Since the Savage River family group was killed, I have not seen their storm-and-circle testing of moose used again by any other group of wolves.

  When the Savage River family group confronted a moose, they tested it before deciding whether to close in for actual physical contact. They began with a careful look from a distance, then they charged the moose, running hard, barking, and making all kinds of fuss. By attacking this way, the wolves may have been deliberately attempting to panic the moose, although it's also possible that they merely became excited and any “panic effect” this may have had on the moose was coincidental. Whatever the case, the wolves generally stormed to within five or ten feet of the moose, stopped, circled, and carefully looked it over for telltale signs of weakness. If the moose acted belligerently enough, the wolves left it within a few minutes, rarely pausing to look back and consider a second try. When they did decide, however, to close in for actual contact—displaying masterful finesse to avoid lightning-like strikes from the moose's deadly front hooves—they almost always succeeded in making a kill. This would suggest that they were able to judge subtle differences between the fitness of animals. As a result, the weakest moose tended to be culled from the population first.

  Capture strategies beyond just a simple all-out chase include deploying individuals at several locations around the prey and ahead on an escape route before beginning a chase. The alpha male of the Savage River family would frequently lie in wait as the rest of the group chased the prey, usually sheep, to him. Driving maneuvers forced prey into difficult escape terrain such as deep snow or heavy brush or even over a cliff—the way Native Americans drove bison or Native Alaskans used rock cairn “drive fences” to funnel caribou. Decoys are also frequently used, and the Toklats were especially proficient at this in hunting caribou. Taking advantage of the caribou's natural curiosity, one wolf distracts the caribou by howling in plain view, while others simultaneously stalk from another direction.

  The nose-to-hind-end killing strategy is used for moose, by far the most difficult and dangerous to kill. The alpha male grabs the moose by the nose to initiate the sequence—an extremely tricky and dangerous move—and the other wolves attack from the hind end. Large sheep and caribou are also killed in this way, especially when experienced wolves jump in to help younger wolves who didn't know what to do or were getting overwhelmed by two-hundred-pound rams.

  This five-photo sequence of the thirteen Toklat wolves killing a moose in March 1973 illustrates the nose-to-hind-end maneuver. It is an obvious way for them to try to neutralize the dangerous strikes of the moose's front feet. The victim is a cow moose that I determined from examination of the remains and tooth analysis to be in poor condition and of extreme age—about nineteen years old. But it was still necessary for the wolves to mount two highly coordinated attacks over a period of more than an hour, illustrating why they usually avoid trying to kill a moose in prime condition. They ate most of the carcass in forty-five minutes, and then stayed with the carcass, feeding and resting, for nearly three days before leaving behind nothing but a pile of fur and a few
large bones.

  Senses, Strength, and Sociality

  The intelligence and prowess that wolves display on the hunt fascinate me. Wolves rely on supersharp senses to locate prey. They have an incredible ability to detect via hearing and smell—even to the point of finding previously unused frozen prey buried ten feet or more under snow and ice, from miles away with the wind blowing in the wrong direction.

  They are able to see prey at great distances, commonly five to eight miles away, even when prey are camouflaged and motionless. This is the most important of their detection abilities in the predominantly open terrain of Denali—although from atop high vantage points they commonly spot prey at great distances in forested areas as well. Groups routinely travel high ridges and peaks during winter, and experienced leaders stop them frequently to scan for prey in distant areas below. Once I watched the Toklat wolves pick out a band of sleeping sheep against a fresh snowfall, motionless white on white, from eight miles away.

  They have excellent endurance, especially in ascending the steep ridges, hills, and mountains that characterize the Alaska Range in Denali, climbing them many times a day during winter, even in deep snow. Their amazing cardiovascular fitness, agility, balance, and grip allow them to climb and traverse steep, icy slopes where an expert human climber wearing crampons and using an ice ax would find the going nearly impossible.

  But while wolves are impressive from a physical standpoint, they still must rely on their even more impressive intelligence and sociality to offset the natural advantages of size, speed, and strength that their prey enjoys. They have excellent reasoning ability—including making intelligent split-second line-of-scrimmage changes during chasing maneuvers as a group, when the prey zigs where it seemed that it was going to zag. They seem to have an uncanny sixth sense or intuition in coordinating ambush and attack, as family members commonly split miles apart to set up prey attacks from several directions.

  Wolves that depend heavily on difficult prey, such as moose and mountain sheep in eastern Denali, require several years of learning from experienced adults in order to become proficient hunters. Much of the hunting, territorial, and related behaviors that I have observed in Denali amount to traditions that young wolves learn during their prolonged period of dependency, which in human terms equals at least a quarter of a normal life span.

  I have seen several of these traditions disappear due to hunting and trapping losses. When the Toklats lost all their adults, the young had not yet learned the sophisticated sheep-hunting techniques, and so relied almost entirely on snowshoe hares for several years (see chapter 8). Storm-and-circle moose testing is a learned tradition that seems to have been unique to the Savage River family. I have not observed any other group use this tactic, before or since they disappeared in 1983.

  Most Dangerous Prey

  At normal levels of prey abundance, experienced wolves neither risk their safety nor waste their energy with a potential meal that does not show almost immediate prospects of success. They are especially selective when hunting moose, the most dangerous of their prey in Alaska. This selectivity with moose is demonstrated by the wolves' heavy winter scavenging, low killing success rates (less than 10 percent), cautious testing behavior, high incidence of old and/or debilitated victims in the kill samples, and by the failure of moose densities to increase following the loss of the Savage River family group.

  Only about 5 percent of the wintertime wolf-moose encounters in Denali result in a moose kill. This rate increases during a deep snow winter, but not by much—it rose to about 9 percent in 1970–1971, the deepest snow winter ever recorded in Interior Alaska. Nor does the number of wolves make much difference, beyond a group size of seven; twenty wolves do not enjoy significantly better killing success with moose or sheep than do seven. Denali wolves usually test an adult moose in less than ten minutes, then leave without attempting to kill the moose about 95 percent of the time. They usually succeed when they do decide to try for a kill, generally within a couple of hours, and sometimes over several days.

  One of Toklat's winter 2002 moose kills, on an extraterritorial foray into upper Riley Creek, far exceeded these normal limits. The Toklat wolves, unable to take her down, instead kept an old cow moose standing in the same spot, with little or no chance for her to eat or even lie down, for at least seven days starting on March 17. Four or five of the wolves left on March 21 and went back home, with no indication that any blood had been drawn yet. The alpha female and two of her older offspring remained and were still in a bloodless standoff with this moose on March 24. When next checked, on March 31, the three wolves were resting nearby and the moose was largely eaten, within the same twenty-foot circle where the standoff had taken place. Most likely she collapsed after days of standing in one spot and eating little or nothing. Killing her over the final few minutes was probably academic. The three wolves ate her almost completely by April 4 and returned to their territory by April 14. This was by far the longest standoff I ever observed.

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  Tweet 21

  June 2009

  No surprises on hike in+out of den; I miss the attack goshawk. Noisy wind increases odds of stumbling into moose or bear, so was xtra alert.

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  Usually adult moose are physically superior prey, so wolves must therefore encounter many individuals to find the smaller percentages that are vulnerable enough to capture and kill. In August 2007, we watched the three Lower Savage adults try to get a calf moose away from a cow moose. The wolves had no chance to take down the cow; she would have quickly stomped them into the ground, especially in the heavy brush that gives her an advantage because of her longer legs. Her ears were pinned back in agitation—an indication of her highly aggressive mood, not fear. The wolves instead focused exclusively on trying to separate the calf. The cow and calf were eating at separate locations as the wolves arrived. The cow had just detected the nearby wolves and immediately started toward her calf. There would not have been a chase and the wolves would have departed with minutes except that the panicky calf began fleeing and the cow had to then run to protect it.

  We noticed that the alpha female in particular was not running directly toward the cow and calf moose but rather somewhat toward their left, anticipating they would veer in that direction. Wolves commonly project prey flight trajectories in this and other ways. The three wolves ran alongside to the left, just behind and to the right-rear of the cow, but to no avail. They could not separate the calf. This was an experienced cow; she was able to stay right behind the calf. When the calf finally stopped, it was no contest; the wolves almost immediately gave up and left.

  Most of the moose calves still alive in the fall are likely to survive predation during the winter. The heaviest predation on calves, by both wolves and bears, occurs over the first month or so after birth in late May, and generally the survivors of this early culling are defended by the most capable mothers—who also offer the best protection during winter. In Denali National Park, 66 to 92 percent of the mortality recorded for moose up to sixteen months of age occurs before the first winter.

  It is often assumed that twin calves, in particular, are an easy mark for wolves. But my observations of wolf-moose encounters in Denali over the past forty-three years indicate it isn't that simple: calves, including twins, that have survived their precarious first month or two are likely to be with the most capable mothers and thus also enjoy good odds of being protected from predators for the rest of the biological year (May–April). A September 2007 sequence shows wolves of the Toklat Springs family attempting to provide a meal for their six four-month-old pups with one of the four-month-old twin calves accompanying an adult cow moose. I am circling above in a small airplane, so the direction of the action varies from photo to photo, and there are some gaps. (See Plates 7–10.)

  Caribou: Flight Paths

  Wolves feature intelligent, innovative tactics in their hunting activities. One underpinning of this behavior is a knack for anticipating the route
s of fleeing caribou, moose, and other prey. Whether several or more wolves are cooperating or one is acting alone, being able to visualize prospective flight paths before pursuit begins is important. Projecting flight paths can help, for example, when setting up an ambush or a maneuver to drive prey into difficult escape terrain.

  Projecting the flight path after a chase is under way and correcting quickly for any errors is similarly important and can improve initially poor odds. I was able to photograph some of this behavior on September 27, 2008, while the Toklat alpha male and female chased a bull caribou for about three miles in Denali National Park. Several times the alpha male left the caribou's direct flight path with what appeared to be clear intent to intercept him at projected locations, and several times he made major “in-flight” corrections. In this case, the caribou still outmaneuvered and outran the wolves, and they gave up. Nonetheless, their moves illustrate that intelligent hunting involves much more than just speed and other physical prowess.

  At first, the light tan Toklat alpha female led her charcoal gray mate as they snuck slowly through willows, catlike, with heads and bodies lowered, to within one hundred feet of the bull caribou. He was walking casually, still unaware. The wolves had first seen the caribou from at least a mile upstream and had run excitedly until a couple of hundred yards away, where they had downshifted into their stealthy final approach.