Grizzly： Yellowstone's Giant Predators ｜ Grizzly ｜ Full Documentary

Tens of thousands of grizzly bears once ranged across the American West, from the Mississippi River to the Pacific Ocean. By the 1970s, American settlers had killed all but a few hundred of them. Only a few small scattered populations remained, one of which was in Yellowstone National Park. Yellowstone's towering peaks and rolling ridges are today home to nearly 600 grizzlies, including two young bears who are struggling to survive in an unforgiving landscape. Thumper, a three-year-old male, is a curious young bear who left his mother's side only a year ago. While he may one day grow into a dominant bear, today he must survive on his own in a valley teeming with predators and prey. Mary is an adult female facing perhaps the most daunting challenge of all, raising her offspring in a landscape where nearly half of all cubs die before they reach adulthood. The Yellowstone ecosystem is one of the most unique bear habitats on earth. No other population of grizzlies lives in an ecosystem so full of large predators and prey species. In a certain sense, Yellowstone is a battlefield where individuals are pitted directly and indirectly against one another in a struggle for survival, a struggle that Mary and Thumper are ideally suited for. But they face a lot of competition from other scavengers and predators. Coyotes, wolves, black bears, and cougars all prowl the landscape, as well as hundreds of other grizzlies. If Mary and Thumper are to survive the next year, they will have to overcome these threats and more, the most dangerous of which is the very species that drove their ancestors nearly to extinction, people. Mary disappeared into her alpine den alone last fall. Now in late April, she's emerged back into a snowy world with two tiny cubs in tow. Winter is slow to loosen its cold grip on Yellowstone. The ice and snow will remain well into May this year. Barely two months old, Mary's twins each weigh less than 10 pounds. While they explore a new and fascinating world, Mary is obsessed with a more pressing matter, finding food. For the next few weeks, she'll depend on an unlikely yet vital food, fresh shoots of grass sprouting along the shores of Yellowstone Lake. Mary ate no food and drank no water during the six months she spent in her den. Her body fat kept her and her newborn cubs alive. Now she must regain more than a hundred pounds of fat during the next six months. If she doesn't, she and her cubs will starve to death next winter. All grizzlies are engaged in a constant struggle to gain the fat they need to survive their yearly hibernation. But Mary is engaged in a second more desperate struggle, raising her cubs. This is her second set of cubs. Both of her first offspring died before they reached their second summer. If these cubs are to survive, Mary will have to feed them, teach them, and tirelessly protect them from countless threats, ranging from male grizzlies and packs of wolves, to raging rivers and automobiles. Located 30 miles to the north of Mary's lakeside home is Lamar Valley, which is some of the most productive habitat in Yellowstone. Thousands of elk and bison live here, as do several wolf packs. It's here, in the middle of a valley that is commonly called the Serengeti of the West, that the young grizzly called Thumper lives. Like all grizzlies, Thumper is remarkably intelligent. But because he is only three, he's also surprisingly curious and playful. Watching him now, it's hard to imagine that one day he may grow to be a mighty adult male, the most powerful creature to roam the valley. He's got a lot of maturing and learning to do, if he's going to survive long enough to fulfill this destiny. These days he's so unsure of himself that he has trouble standing up to a pack of coyotes, who've decided they don't want him around their den. The bulk of Mary and Thumper's diets comes from grasses, roots, pine seeds, and berries. They've also learned to seek out more obscure foods, such as insects. But in early spring, many foods aren't yet available. What is available is the most nutritious food, meat. Grizzlies are large, weighing up to 800 pounds. They're fast, able to run 35 miles per hour, and they're strong, able to kill a bison with a single blow. But they're not true predators of adult animals. In Yellowstone, that's a singular honor, belonging to wolves. As big as grizzlies are, adult bison and elk are even larger, and while bears occasionally kill large prey, it's usually too much of a risk. But they are relentless scavengers, and they prowl the landscape in search of carcasses of animals that were killed by predators or died from natural causes. Mary's twins are steadily growing in both size and rambunctiousness, and she's kept them safe so far, possibly because she has a unique factor working in her favor. The two greatest predators of cubs are adult male grizzly bears and wolves. Mary lives in an area where she is not very likely to encounter either of these, along a road. Mary may have made a conscious decision to live here, knowing she would encounter fewer threats to her cubs. But by living in such close proximity to humans, she has inadvertently exposed her twins to an even bigger danger. Conflict with humans is the leading cause of death for grizzlies, so Mary is taking a gamble by living here. Like all grizzlies, Thumper eats lots of vegetation, but he's an odd bear more curious than most. He's interested in the bison and elk that most grizzlies ignore, and today he has discovered a bison that's too sick to stand. He senses the old bull's vulnerability and wants to attack. But even weakened, the bull is an intimidating target, and today Thumper's confidence doesn't yet match his curiosity. Having passed on the opportunity to prey upon an old sick animal, Thumper now takes a shot at the next best thing, a young animal. He's trying to separate a newborn calf from its mother, and his strategy appears to be working. But he's chosen the wrong species to attack. Bison protect their own, and a nearby herd comes to the calf's aid. Even a full-grown grizzly is no match for a herd of bison, so Thumper must quickly retreat or risk being gored. Luckily for him, he can usually track down the carcasses of elk that wolves killed, but he usually has to scavenge what he can from carcasses that bigger bears have already picked over. This large male grizzly has been eating from this elk for three days, sleeping on it to keep other scavengers from stealing a bite. Thumper's followed his nose to the carcass, but it looks like he'll have to wait his turn just like the wolf that killed the elk. But he shockingly decides to take a huge risk by challenging the bigger bear. While he escaped unharmed, the big male could have seriously injured him. Thumper's clearly gaining confidence, but perhaps at the cost of caution. Beaten and hungry, Thumper moves on. The carcass he tracks down the next day is more promising, with no other grizzlies in sight. His only competition is a black bear that he's nearly twice as large as. But what happens next is unheard of. The black bear not only stands up to Thumper, but chases him off. It seems as if losing the fight with the big male grizzly has wrecked his confidence. If Thumper is going to survive, he can't afford to be losing these battles, and if he is ever to fulfill his destiny of becoming a dominant grizzly, he'll eventually have to defeat another bear. Back at Yellowstone Lake, Mary and her cubs are experiencing another in a seemingly endless string of May snowstorms. The family is able to avoid some threats by living near a road, but they're missing out on the carcasses of elk and bison that wolves killed. This doesn't mean they don't eat meat, they just have to find smaller meals. Squirrels, voles, and mice provide the family with vital sources of protein. The twins will spend just over two years with their mother. During this time, they'll have to learn everything they'll one day need to survive on their own. Many of the foods they'll rely on are only edible or available for a short time, and often only in specific areas, and Mary will teach them where and when they can find these staples. The cubs' most important food remains their mother's rich milk, which has four and a half times more fat and 17 times more protein than human milk. Now three months old, Mary's cubs are steadily growing, and so far their mother's been able to protect them, but a perilous time of year has arrived. The grizzlies' mating season stretches from late spring to early summer. Adult males are obsessively searching for females to mate with, many of whom initially aren't at all interested in their advances. But eventually, the females come into estrus and are receptive to the eager males. It was a year ago in a sheltered cove that Mary mated with her cub's father. After spending two weeks together, Mary went out of estrus and found herself held captive by the still enamored male. Her only way out was to meet force with force. While the mating season ensures the survival of the species, it is also the most dangerous time of the year for cubs. Mary won't mate again during the two years that she's raising her cubs, but a male bear that's been following the family knows he can bring her back into estrus by killing the cubs, and now he makes his move. But a cub's frightened cry puts Mary into action, and for now she's able to chase him off, but he'll be back. Today, Thumper's nose has led him to the carcass of an elk that a pack of wolves killed last night. He must tread carefully because the pack is more than a match for him, but he's in luck. He only has to confront one wolf. This is a fight Thumper can win. The wolf has no hope of beating Thumper in a fight, so its only hope is to intimidate the young bear. When that fails, he tries to get one final bite of meat. This victory will go a long way in turning Thumper's fortunes around. With no other grizzlies around, he'll finally have a chance to eat his foe. Unlike his encounter with the black bear, this time Thumper won a fight that he should have, and his confidence has returned at an ideal time. It's now early June, and elk throughout the ecosystem are giving birth. For grizzlies, this is a bountiful time of year. Thumper's scouring the landscape, searching for and pouncing on the helpless calves. For the first few weeks of their lives, the calves are too slow to outrun predators. Their only defense is a near lack of scent that allows them to hide from predators. But the grizzlies' extraordinary sense of smell allows them to track the calves down. For the next few weeks, Thumper will feast on the calves. Mary is also hunting calves, and with two cubs to feed, she's persistent. Every calf she kills provides vital nutrients that may ensure not only her survival, but that of her cubs as well. When the elk calves are several weeks old, they're fast enough to join the main herds, and as fast as Mary is, she's no longer fast enough to catch them. She and her cubs will now return to a more mundane diet. Living near roads helps Mary avoid male grizzlies and wolves, but she's traded these two dangers for another deadly threat. The lake area is popular with grizzlies and people. In addition to roads, there are also campgrounds, stores, and houses. As the family makes their seasonal movements in search of food, it's impossible for them to avoid running into people. While searching for routes to dig up, Mary's found herself stuck between a bay and a campground. Her cubs' reluctance to swim the channel funnels them towards the campground and trouble. So then I think, you know, that's, that's enough reason for us to go ahead. Okay. People came and said that there was, um, footprints. There were footprints up by the farthest tent up there, which is one of my girl's tents. And we were warned that we were in the bear highway when we camped here, but now that there's actually been sightings, they're going to move us to a different location. We'll move to lower ground. We're closer to the ranger station due to the mom of bear and her babies and my babies. Bear managers are determined to keep bears out of campgrounds and other housing areas because they could easily find garbage or human food here. The grizzlies' considerable intelligence ensures that a single garbage can or picnic basket can be all it takes for them to view humans as a source of easy food. If this happens, they can become an aggressive threat. Because of this, eating human food often results in a death sentence for grizzlies. As far as the park service is concerned, Mary and her cubs are pushing it. Not for long. She'll be back. As usual, Thumper's been busy looking for carcasses and today he's been successful. But he's shown up wearing a Park bear managers captured him a week ago and put a radio collar on him so they could track his movements. Like the area around Yellowstone Lake, Lamar Valley has a road running through it. But here the road doesn't dissuade most bears and wolves from being around people. The hunting and scavenging are simply too good. Thumper's become very comfortable being in the Likewise, the people have become very comfortable in the presence of grizzlies. For a curious young bear like Thumper, this is a dangerous situation. And the careless actions of park visitors have gotten him into serious trouble. A year ago, two campers illegally left food in their unoccupied tent at Pebble Creek campground. Other campers videotaped what happened next. Attracted by the odor, Thumper dismantled and thumped the tent. This behavior, which he exhibited more than once, gave him his nickname. After trying to trap him for some time, the managers finally caught and collared him to track his movements. And what they've learned is tragic. They think he's been getting into garbage in a small town just outside of the park. For an already troubled bear such as Thumper, this means a death sentence. There is a very good chance that this bear will be killed. It will be, but we wouldn't find an acceptable place to put it, and we'll have to kill the bear. That's the reality. The rangers will use the elk carcass as bait. Once trapped, Thumper will be removed from the park. But as usual, he doesn't fail to surprise. Returning to find his meal gone, it seems as if he understands what's going on. Has being trapped once taught him all he needs to know? Whatever his motivation, Thumper heads away from the trap into the park's back country. But the park service won't simply give up in the pursuit of him. Back at Yellowstone Lake, Mary and her cubs are still running afoul of park rules. The park service's corral is full of grass to eat, but it's right in the backyard of several homes. This time, the park rangers use more drastic measures. It remains to be seen if these firecrackers will be enough to scare the bears away for good. If the family doesn't stay away, they may find themselves facing the same death sentence as Thumper. Every year in late July, over 100 grizzlies begin flocking to several of the region's most foreboding peaks and ridges. They come in search of a seemingly insignificant food source. Moths. Millions of army-cut worm moths travel from the plains to a handful of 11,000-foot peaks every summer. The grizzlies dig for the protein-packed moths for several hours every day, eating them by the thousands. A bear can consume 20,000 calories a day, so the weeks spent at the alpine sites play a vital role in preparing them for hibernation. Mother grizzly bears have been teaching their cubs the location of these feeding sites for hundreds, likely thousands of years. Up here, it can seem as if grizzlies have all the space and wilderness they need. It's easy to forget that their habitat is in peril. The park service hasn't caught Thumper, but they're still tracking him. He's been staying out of trouble, and there's even talk that the park will lift Thumper's death sentence if he can stay out of trouble until winter. While exploring his territory, he's discovered a bull elk with an injured rear leg, and this time his confidence matches his curiosity. But even injured, the elk is too strong to take down. Thumper's come up short again. Mary and her cubs have also been staying out of trouble, and now they've returned to their primary habitat northeast of the campground. The family isn't trying out any radical hunting techniques like Thumper. They're sticking to a basic grizzly diet. While the twins have grown dramatically, they remain vulnerable. The male grizzly that Mary defended them from last spring is again following the family. This time she asserts her dominance without having to raise a paw. Mary has met and answered every threat her twins face this summer. But the larger threat, the threat that will determine the survival of her species, is beyond her control. Both Mary's and Thumper's interactions with humans nearly led to their deaths this year. Their experiences underscore the reality that the greatest threat all grizzlies face is people. Grizzly bears will survive only if we humans allow them to, only if we accept their presence. Living with them isn't always easy because it requires added responsibilities. Some people living around Yellowstone accept these responsibilities, making an effort to get along with grizzlies. But others don't. And the same forces and views that push the grizzly to the brink of extinction persist today. Over the past century and a half, human intolerance nearly killed all of the West's grizzlies. The grizzlies' future depends on one question. Have we let go of enough of this intolerance to live alongside of grizzlies, not only in wilderness but also in the rural areas surrounding the greater Yellowstone ecosystem? In late August, a vital food begins attracting animals from across the ecosystem. Whitebark pine trees growing in stands above 8,000 feet produce highly nutritious seeds, and this year they've grown a bumper crop. Ravens have flocked to the high elevation stands to feed on the seeds, as have scores of Clark's nutcrackers. Rather than simply eating the seeds, the nutcrackers collect and store them in small holes they dig throughout the forests. Like the nutcrackers, squirrels also gather the seeds for use during the coming winter. But the squirrels gather entire cones, storing hundreds of thousands of them in underground caches. These stashes of cones, intended to help squirrels survive the coming winter, also help grizzlies in their quest to fatten up. Mary and the twins are traveling from cache to cache, digging up all of the seeds they can find. They've entered a physiological state called hypophagia, which means that their bodies are compelling them to eat as much as they possibly can in order to make a final push to prepare for hibernation, which is now only weeks away. Grizzlies aren't the only bears searching for seeds. Black bears have also trekked up to the whitebarks. But unlike their cousins, they don't have to depend on squirrels to gather cones. They simply climb into the tops of the trees and gather them themselves. For bears, the importance of whitebark seeds goes beyond calories. During a poor whitebark seed year, bears flock to low elevation valleys, which are often full of humans. The bears' desperate search for food leads many into conflict with people, which results in dead bears. But this year, the large cone crop has kept Mary and her cubs up high, out of trouble. The park service is continuing to keep an eye out for them, but for now, they're in the clear. Mary's greatest success is the survival of her cubs, and while she will protect and teach them for another year, keeping them alive until fall has been an important accomplishment. It looks like the second time around may be the charm for her. Now, in late October, the family will begin to make its way to the high slopes they hibernated on last year, perhaps sleeping in the same den. While Mary's returning to her den now, Thumper will wait several more weeks before he travels to his den. He's searching Lamar Valley for one last carcass to feast on before he hibernates, and as usual, his nose doesn't let him down. But another grizzly has already claimed it. Thumper's experienced many failures this year, but now he's been given one last chance to end it in triumph. Unfazed by the other bears' charge, Thumper finally asserts himself. Thumper's victory has provided him with a wealth of food that will ensure that he survives the long winter, which has finally arrived. Before entering his den, Thumper makes one last stop in a high whitebark pine stand and eats his final meal of the year. Only now he's shown up without a radio collar. It's fallen off earlier than the park service intended, and its absence is significant. Because he's stayed out of trouble since early June, the park service has lifted his death sentence. Thumper, a bear once slated for execution, has found his way. After a year of trials and tribulations, it appears he has learned not only how to hold his own against other bears and scavengers, but also how to avoid further conflict with humans. The urge to hibernate has been growing stronger and stronger, and now Thumper, barely able to stay awake, can no longer hold it at bay. The time to sleep has come. But he will go into his den a changed bear, no longer an insecure youngster. He's now a seasoned adult who may one day become the dominant bear in the valley after all. His survival is a testament to both grizzlies and people. Each species has made a bit of a compromise. Each has learned to accept the presence of one another. Each has agreed to share the wild heart of the west. Mary and Thumper's ancestors evolved to survive on the open tundra landscape of the ice ages. Alone and threatened by larger predators on a vast treeless landscape, all they could rely on was their own ferocity, their own courage. They've always faced threats unrelentingly head-on. But humans are the one species they can't overcome. And humans, used to bending and shaping nature to our needs, has, in the grizzly, found an animal that won't quietly submit.