Seconds later, the caribou saw them and bolted into high gear, as did the wolves. The charcoal gray male veered somewhat to the right, apparently because the first bend of the river was to the left, then back right, and the caribou was running near the river. When wolves overtake a caribou near a river, the caribou often makes a last stand in the river, where it has an advantage because of longer legs. Thus the caribou's flight path is likely to remain near the river and curve at least roughly with the river bends. This provides opportunities for pursuing wolves to gain ground by cutting across the bends. However, this caribou thwarted them by crossing to the left side of the main river channel. They also crossed and quickly caught up, with the alpha male now running ahead of his mate.
The male wolf raced to and then along a side channel that eventually joined the main channel downstream. We noticed that he was focusing more directly on a projected point of interception, veering to the left, away from the caribou's immediate flight path. Obviously he thought the caribou would continue to follow the river and that he could intercept him where the river bends back to the left. His mate was lagging somewhat behind after crossing back to the right side of the river, perhaps hoping to keep the caribou on the male's side. The side channel provided a shorter route to the projected intercept, and the wolf initially gained on the caribou. But the caribou changed course, back to the right side of the main river channel.
The male immediately corrected accordingly and gained again on the caribou by powering across the several-foot-deep river in just a few leaps. The caribou ran somewhat to the left, along the left-right bend of the river. The wolf didn't follow the caribou; he aimed straight across the river bend instead, toward a projected intercept, where his mate rejoined him. But once again the caribou thwarted the wolves, beating them to the next bend. The wolves loped along somewhat beyond the bend but then gave up as the gap widened.
One January in Denali I was treated to a scene that could have been straight out of the Ice Age, as wolves and caribou once again did their age-old dance during a hunt on the wintering grounds. Sometimes the wolves end up with a meal, sometimes the caribou prevail. But always it is a fascinating thing of beauty to watch.
By midwinter, Denali caribou move northeastward to a traditional wintering area in flatter, more open terrain along the northern and northeastern park boundaries. There they forage primarily on lichens, mostly in scattered small groups. This represents an annual windfall for resident wolves such as the Stampede family. The wolves move almost constantly throughout the area, searching for and testing caribou until finding the next fresh meal or frozen winter kill. At the time of the photo on the next page, the Stampede family consisted of four adults and the four (now adult-sized) surviving pups from the litter they produced in May 2008.
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Field notes #110
March 2004
5:45—the wolves reached the top and began picking their way along the jagged 5,000 ft rocky knife ridge with 60–70+° drop-offs on each side of the ~ 5 ft wide top. The sheep seemed to more or less anticipate that they were coming. The wolves were out of their view most of the way due to rocks, but then they appeared, less than 100 ft from the sheep. The sheep immediately ran down the opposite (NE) side of the mtn—a 70 degree or greater icy pitch—to some safe rocks perhaps 100 ft below—the wolves seemed to know it was futile. They ran the 100 ft or so to the top edge of the ridge, from which they peered down at the sheep. They made no attempt to pursue down this pitch—it was obviously way too treacherous for the wolves—suicidal for them but not the sheep. After loitering for a few minutes, the wolves began traveling at a normal pace northward down the relatively gentle north slope of Divide Mtn. Again the alpha pair was in the nose-to-tail mode. Due to light, we left them at the base of N Divide Mtn.
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As we approached in the research airplane, the eight Stampede wolves were moving at a steady pace across the open terrain toward a group of ten caribou, including several calves, foraging just out of view in a creek bottom, several miles away. The wolves seemed to know exactly where the caribou were, but the caribou were oblivious to the oncoming wolves. The photos show what happened over the next ten minutes.
Knife Ridge Hunting
The experienced Toklat wolves seemed to know every significant sheep mountain in their nearly one-thousand-square-mile territory and checked most of these regularly throughout the winter. They could pick out sheep at almost unbelievable distances, especially when scanning from one high ridge or mountaintop to another. As mentioned earlier, I once observed them spot sheep from eight miles away; they intently studied the twenty white sheep sleeping on a slope against a fresh white snow cover from another slope, then they excitedly headed straight to the sheep, traveling with the wind, and caught one.
The Toklats developed impressive search-and-pursuit tactics that utilized the treacherous, rugged terrain to advantage, including various kinds of ambushes and, especially, surprising sheep from above, forcing them to flee downslope, away from the best escape terrain. One tactic seemed to involve deception. Usually the wolves left soon after a sheep fled beyond reach onto a narrow ledge, spire, etc. However, sometimes they waited quietly nearby, out of view, for up to a day or two. Unable to eat, drink, or often even lie down, the sheep would finally come out to a vulnerable location where the wolves were afforded an opportunity to ambush it. (See Plate 11.)
Just learning to negotiate the high, icy knife ridges, peaks, and slopes usually required extensive guidance from experienced adults. Alongside these skills, Toklat wolves displayed impressive physical prowess, regularly climbing up and down the steep mountains like they weren't even there. I typically recorded instances of them ascending a sixty-degree snow-covered slope with an elevation change of eighteen hundred feet in less than twenty minutes, with no rest stops, and then breaking into intense play at the top.
Several times pilots and I watched in disbelief as Toklat wolves literally skied, stiff-legged, straight down icy chutes, adjusting their upraised tails back and forth for balance. We watched three Toklat wolves do this while trying to intercept sheep that were fleeing below from several other Toklat wolves chasing from another direction. The three bounded over the top of a high, narrow, rocky ridge at a full run and jumped immediately—apparently without looking first—into the top of an icy chute and skied straight down the seventy-degree, three-thousand-foot run; they zipped down this chute faster than any Olympic downhill ski-racer I've watched. At the bottom they switched immediately to a full run, although in this case the sheep escaped to safety on a nearby ridge.
The Savage River family, Toklat's former neighbor to the east, developed similar sheep-hunting skills over its history of at least seventeen years. After the twelve Savage River wolves disappeared in the winter of 1982–1983, with indications of illegal aerial wolf hunting, three groups—Headquarters, Sanctuary, Mount Margaret—successively recolonized major portions of the Savage vacancy over subsequent years. However, each was also killed off due largely to human causes. And none hunted sheep or developed sheep-hunting skills to the extent I observed for Savage River—nothing even close. None of these groups have been able to last long enough, so there hasn't been enough continuity to facilitate the necessary learning. And since the losses that Toklat also suffered, it seems unlikely that Toklat's sheep-hunting skills will reappear anytime soon either, especially with the remarkable fine-tuning that the Toklats had developed.
The Importance of Scavenging
Denali wolves make the rounds through all of their territory regularly, particularly in winter, and test each moose at least once or twice a season. Small wonder that, based on standard indicators such as calf production, twinning rates, bull-to-cow ratios, stability of size, and other factors, the moose herd within eastern Denali is at least as fit a herd as has been reported anywhere. It seems the moose are well “managed” by the wolves.
A real test of the herd's fitness and the health of the entire wolf-moose relation
ship came in the winter of 1970–1971, one of the severest on record for Denali. Because of the deep, crusted snow and severe cold, moose were more vulnerable to both wolf predation and mortality from cold and starvation than in a normal winter. In addition, because of their weakened condition, only slightly more than half as many cows as usual produced calves the following spring. Yet the decrease in the size of the herd between my surveys of fall 1970 and fall 1971 was only 10 percent. The next year, fall 1971 to fall 1972, there was no further decrease.
What prevented a marked decrease in the herd during such a severe winter when there were plenty of wolves? Obviously, wolf predation did not increase as one might expect. To my considerable surprise, winter kills—the frozen carcasses of animals that died from cold or starvation—became an important source of food for the Savage River group. In fact, in the winter of 1970–1971, more than 40 percent of the Savage River family's total diet by weight was derived from winter kills. Even more surprising, during the following winter of 1971–1972, 60 percent of their diet by weight came from winter kills. For the Toklat family during 1970–1971, winter kills accounted for 59 percent of their diet, while in winter 1971–1972 the figure was an almost unbelievable 85 percent.
These estimates are not based upon wild speculation, for I have been able to follow both groups for long, continuous intervals during winter, obtaining a record of all fresh kills and winter kills utilized during each sample period. In the winter of 1970–1971, for example, I aerial-tracked the main Savage River family group for a total sample period of sixty-four days spread throughout the winter, one of the longest visual records ever reported of a wolf group's activities in the wild during one winter. These samples enable me to make reasonable estimates of what and how much the group ate for the entire winter.
Also, both families denned outside primary moose calving areas that summer of 1971, so although the moose calf crop was smaller than usual, fewer were taken by wolves and a higher percentage survived. As well, the wolves spent less time hunting moose the following winter. This trend effectively allowed moose to recover more quickly from the severe winter.
Scavenging of frozen carrion from prey that have died from cold stress, starvation, or other nonpredation causes is much underacknowledged but of great importance as a winter food source for Denali wolves. Especially during and immediately after a severe winter, wolves can become more like scavengers than like predators.
Trappers' tales of wolves wantonly killing prey and eating only the gut portions are for the most part just that—tales. Never have I seen wolves make a fresh kill and leave a significant portion of the carcass uneaten. To the contrary, when wolves are done with an animal, usually little except large bones, stomach contents, and some hide and hair remains. Often, even the hide and hair are eaten.
When a trapper finds a relatively intact but hollowed-out moose carcass with wolf tracks all around, it is almost certainly the remains of a winter-killed animal that wolves have fed upon, not a kill they made. During the coldest months, when wolves find a winter-killed adult moose, they are generally able to eat the softer gut portions but relatively little of muscle areas, which may freeze as hard as steel. When they finish, the carcass takes on a hollowed-out appearance, easily leading one to erroneously conclude that they killed the animal and ate only the internal organs. If the wolves are undisturbed, they will return repeatedly to a winter kill and eat most of the carcass as it thaws. I have been able to observe wolves in the act of finding and utilizing many such winter kills.
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Tweet
July 5, 2009
Confirmed 9 Toklat pups on yesterday's research flight. Dom adults hunting 4mi (6 km) away; 2 young adults with pups at pond area of den.
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Once a dozen or so wolves kill something, it gets devoured completely, and very fast. I've seen a twelve-hundred-pound moose mostly eaten within forty-five minutes. And in testament to their harmony within the group, I never saw a feeding order, not even when as many as nineteen wolves ate at a small kill.
I once saw a two-hundred-pound ram virtually disappear in twelve minutes—except for the skull, horns, hoofs, a few large bones, and scattered tufts of hair and hide. The large ram, which I later determined from horn annuli to be about thirteen years old, had been feeding with two younger mature rams near a low rock outcrop. The sheep and Savage River family of wolves saw each other while still several hundred yards apart. As the wolves slowly worked their way toward the sheep through deep snow and heavy willows, the two younger rams ran for safer rocks. The older ram remained where he was, and soon he had seventeen wolves for company. Now, to reach the safer rocks he would have to cross right through the group of wolves, which is exactly what he did. With a slow, hesitant trot, he passed within ten feet of most of them. The wolves stood motionless and alert, watching the ram as he moved literally right past their noses. It was as if his action so surprised them that they were unable to react.
Not until the ram was twenty feet away and began speeding his pace did they move. Almost simultaneously all the adults and a few younger wolves began full pursuit. The ram began to run, but within one hundred and fifty feet, the beta male, LT, overtook him and grabbed him by the left rear flank. The alpha pair and a black yearling caught up, and together these four hauled the ram down. Most of the other wolves caught up while the ram was still standing, but none attempted to join in until the first four hauled him down. All seventeen wolves crowded around the carcass and within twelve minutes they had eaten virtually all edible portions, leaving little but the skull, horns, spinal column, a few leg bones, some scattered hair, and the stomach contents.
There are those rare times when wolves will successfully kill prey but then lose it. If, for example, there are only a few inexperienced wolves, a bear might be able to successfully chase them off. And then there are the vagaries of environmental conditions themselves, as the three photos at the end of the chapter show. A single wolf chased a caribou along a segment of open river. The caribou entered the water to escape, but the wolf followed and successfully took it down—only to lose it to the current, which carried the carcass under the ice. The wolf followed the river to the next open segment, with no luck. No doubt, however, the caribou was scavenged by this wolf or others the following spring.
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Snapshot: Pups at a Sheep Kill
Priscilla Feral
Priscilla Feral has been president of the international nonprofit Friends of Animals since 1987, as they chart the path that brings critical habitat and environmental issues into the animal-advocacy sphere. Priscilla met Gordon after the group's protests against Alaska's wolf control program prompted the governor to suspend the state-sponsored wolf killing. Friends of Animals sponsored Dr. Haber's work for seventeen years.
This was close to the last time I saw Gordon. We went into the park, and he used a receiver to find wolves. There were times we'd drive for eleven hours in his truck and never see a wolf. This time we went to an area the Toklat wolves were often using to train their pups to hunt hares.
But then we had a surprise: the Toklats had killed a sheep just off the road. Gordon showed us how one sheep probably went up while another went down, a kind of one zigged and the other zagged, and the one that zagged went the wrong way and got trapped.
We watched for hours as the wolves kept going back and forth, rallying the pups to come to the remains of the sheep. These little pups were just playing and yowling and all excited. Every now and then the mother would try to get them to cut it out, try to convince them that this sheep-eating was serious business. But then the pups would get distracted again, and get in the river and start running back and forth.
Finally one pup figured out that he could pick up a piece of the carcass; he started carrying it around like a trophy, his head held way up. Then all the pups joined in and started picking up pieces, throwing them around, gnawing on them.
We watched this for four or five hours, and it was absolutel
y captivating. And since Gordon knew all the bus drivers, he let them know and gave people an opportunity to stop and see what was happening.
Gordon taught me so much. I loved all these animals—wolves, bears, moose, all of them—without any direct experience. And then Gordon gave me information, he gave me these experiences, which made me love them all the more.
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CHAPTER 8
TOKLAT'S SWITCH TO HARES: SURVIVORS SEIZE AN OPPORTUNITY
IN 1997, HABER FREED A SNARED WOLF, WAS SUED BY THE TRAPPER, AND WAS fined $190,000 by a jury in the trapper's hometown of Tok. Haber acted, he said, under an agreement with the Alaska Department of Fish and Game. The snare holding the wolf was surrounded by caribou carcasses; such baiting is illegal, so Haber contacted the state and claimed they told him they'd free the wolf. When they did not, he freed it himself. ADF&G later denied this conversation, however, and called Haber's actions illegal. The state investigated both the trapper and Haber but declined to file any charges, so the trapper sued Haber and won. The freed wolf, who wore a radio collar from the Yukon–Charley Rivers National Preserve, later died of an infection from the snare.
Like some of Denali's wolves, this wolf was snared just outside the park and preserve boundary—this time in the Fortymile region. Haber had been studying wolf family groups in Denali's neighboring areas, especially those with intensive predator control programs such as the Fortymile, beginning in the 1980s. His research with these family groups led him to conclude that many wolves killed through predator control were actually from surrounding areas, having followed migrating prey in winter. In areas like Fortymile, some were also national park wolves—family groups who primarily resided in Yukon–Charley Rivers National Preserve.
Among Wolves: Gordon Haber's Insights into Alaska's Most Misunderstood Animal Page 12