Frozen Frontier & Grizzly Summer | Wild Yellowstone MEGA Episode | Nat Geo Animals

[HOWLING] NARRATOR: One wolf pack. One leader. [GROWLING] One Place. And one focus... Survive. ♪ [MUSIC] ♪ [ERUPTING GEYSERS SOUND] This is Yellowstone, as you've never seen it. Living here is not easy. And winter strikes the hardest. A season of punishing extremes... ...Where everyone must fight for their life. [HEAD BUTTING] Yellowstone's winter is the ultimate test. The wolves of greater Yellowstone are on the hunt... This is the Dark Wolf's first winter as leader Her mate was killed. Now she's in charge. The pack is young... Dark wolf must teach them how to hunt as a team. ...Or they won't live through winter. Their first lesson... How to take down an elk five times your size. The wolves' only chance is to work together. But the pack doesn't keep up. One good kick could crush her skull. Hunting big game alone is futile. She must teach the pack to work together... or they won't last. In winter... Everyone needs a strategy to survive. For some, preparation began months ago. October... In just a few weeks this beaver pond will freeze solid. The devoted parents who live here must be ready... Lives depend on it. Inside the beaver's lodge are four young kits. Each one eats its weight every week. [KITS SOUND] So mom and dad must stockpile six months of sticks. Or their children will starve. No time to lose. [BIG SPLASHING SOUND] It takes nearly one hundred trees to feed the family through winter. That's a ton of wood. The icy water keeps their produce fresh for months. Today, Dad's in charge of lodge maintenance. To keep out the draft he seals any holes with mud. No self-respecting beaver dad has a leaky roof. Mud... Moss... And sticks... All make perfect insulation. A well-made lodge can be 100 degrees warmer inside than out. [RIVER SOUND] [KIT SOUND] And it's ready just in time... strikes without warning... As temperatures plummet, tensions rise. It triggers Yellowstone's ultimate fight club... The bighorn sheep rut. Every big testosterone raging ram considers himself a contender. The arena-a coliseum of 800 foot high cliffs. Their feet are built to grip the rock... But sheep... ...do fall. The last ram standing gets to mate. This big old ram is reigning champ. But his trials have just begun. Each ewe is only receptive for two days a year. He smells carefully... to see if they're ready. But the ewe's powerful scent draws a crowd. Transfixes them. Call it obsession. As the testosterone peaks ... ...so does the aggression. The champ must constantly show who's in charge. Intimidation is key. Smaller rams know when to walk away. Low blows are fair game. But the old champ's trials have just begun... This huge, young brawler wants a shot at the title. And he won't leave without a fight. The main event. Challenger versus Champion... Winner takes all. NARRATOR: The reigning ram and his heavyweight challenger size each other up. The ewes await their champion. [HEAD BUTTING SOUND] Their massive horns are used as both weapon and shield... [HEAD BUTTING SOUND They weigh up to 30 pounds ... ...As much as all the bones in their body, combined. A massive tendon keeps their head on their shoulders... Two layers of skull bone absorb each collision. The force of this impact... Could kill a human-instantly. It's too much for the old ram He has no fight left. There's a new champion in the herd. At two miles high, these mountains shape Yellowstone's weather. They surround the park... They sit at the end of a five hundred mile corridor forged by Yellowstone's super-volcano. This corridor is also a weather expressway. Funneling moist Pacific air straight to Yellowstone. When this moisture collides with the mountains it turns to massive amounts of snow. But there are some who use snow to their advantage. The red fox is built for winter. At only ten pounds he doesn't break the snow's surface. So he can search far and wide for prey. But how do you find... what you cannot see? His solution. Big ears. The catch? His victims are under two feet of snow. But he can pinpoint the faintest sound... [HOWLING WIND] The fox locks onto a target. A meadow vole. But what now? If he digs, the vole will flee... Instead, he flies. Neither one will give up. Just a small bite... But in winter, every calorie counts. The Dark wolf has her pack on the move. Thirty miles and counting. And still no big meals. The younger wolves still have much to learn. Most days are spent searching for a lead. A wolf's nose is a hundred times more sensitive than a human's. The faintest scent tells them who was here... ...and when. The Dark wolf picks up a promising trail... ... Droplets of blood from an injured elk. This could feed her pack for several days. Since wolves returned 20 years ago, elk have learned to avoid them The herd splits up when wolves appear... They hide under the cover of forest. The wolves know he's here... ...Somewhere You can't hide blood from a nose this good. The hunt... is on. NARRATOR: The wolves must work together... Even a wounded elk puts up a fight. They take turns leading the chase... ...Looking for weakness. The elk makes a clever move. The stream buys him some time. The inexperienced youngsters await the Dark wolf's move. But the pack has lost the advantage, and they know it. Another failed hunt... [HOWLING WOLVES] Another hungry night ahead. By now most of Greater Yellowstone's six hundred grizzly bears are hibernating high in the mountains. But this huge male is still awake, and for good reason. Fresh bison meat. But even the mighty grizzly takes cover, as winter closes in. Surviving winter's wrath means knowing where to look for food. Open water is a great place to start. This bobcat is hunting water birds. A crafty ambush predator ... Silent... ...Patient ... And always on the prowl. Her latest kill Is a huge trumpeter swan. She must defend it against her mortal enemy... The coyote. [RAVEN SOUND] A feather is all he can get. Score one for the cats... The coyote needs a softer target. One that he can steal from... or better yet... kill. [WATER CASCADING SOUND] While some suffer Yellowstone's early winter... River otters are in their element. But the fun is coming to an end for This mother and her nine-month-old pup. Their home on the Yellowstone River is freezing up. But it's not frozen yet. So they'll feed here while they can. The pup is still learning to fish. It's easier just to steal moms. But he must learn to fend for himself. Soon she'll send him on his way... ... And there are many dangers in Yellowstone winter... A starving coyote will eagerly kill, and eat-a young otter... NARRATOR: The coyote's ready to attack. The otter's only chance is in the water. The coyote is patient... looking for a chance to strike. He can swim... ...but not like an otter. Mom and her pup are safe, for now... But Yellowstone won't let them off that easy. Soon almost everything will freeze. Without open water, the otters will be in trouble. Yellowstone even tests its largest animals. Bison have lived here since just after last Ice Age. They've survived ten thousand Yellowstone winters. But It's this calf's first. Winter forces them to search for food. The calf must keep up. The bison are not heading to greener pastures... ...But warmer ones. Yellowstone's geyser basins stay open all year. Thanks to the chamber of molten magma boiling under the park. Beyond the thermals the freeze is happening fast. Ponds are first to set... ... Locking the beaver lodge in ice. Then slower-flowing streams and rivers. Then the faster ones. Winter even tames the Rockies' largest waterfall... Lower Yellowstone Falls. The otters are now in crisis mode. There's only one hole left in the ice. And it's freezing up to. They need to leave... ...and find a new home. But Mom is cautious. With a coyote on the prowl, she'd rather hold tight here for now. But the pup's natural instinct is to wander. This could be a fatal mistake. [OTTER SOUND] The young otter is caught out. His eyes are a designed for life underwater. Out here, he can barely see. He's lost... And alone... [ROARING] Halfway through their trek the bison mother is breaking trail. And struggling. Her calf can only keep up by walking in her footsteps. [ROARS] At its worst, Yellowstone's bitter winter can kill hundreds of bison. At last... a sign of hope. Warm water is keeping this river from freezing. The geyser basin must be ahead. So close... But Yellowstone is not done yet. Enter the lone wolf. Hungry. And desperate NARRATOR: One solitary wolf... ...Against a thousand-pound devoted mother. The wolf will try to lead her away. Then go for the calf. [ROARING-GROWLING] But it won't work. Mom has seen it all before. The mother otter has not yet found her pup. He's lost, further down the frozen river. [OTTER PUB SOUND] Too far for mom to hear his calls. But the coyote hears him. Only the deep snow keeps him at bay. Mom finally picks up a faint scent... The pup's survival depends on who reaches him first. At last, mom hears her son. And he hears her. No time for greetings. The coyote is closing in. They need to get to open water quickly. And they know just how to do it. Escape at last! In midwinter, the night sky puts on a show. But clear skies can descend into deadly cold. Temperatures can drop below minus 60 degrees. Stealing energy from all. And finishing off the weak. The savage cold is Yellowstone's biggest killer. These winterkills help many others survive. Finally... the hungry coyote catches a break.... A bison carcass. He can't let his guard down. Wolves have been feeding here. Fresh meat is hard to leave. But you don't mess with wolves. If they find him, they'll tear him apart. NARRATOR: With wolves on the prowl, the coyote better make this meal 'to go.' Easy come, easy go. The bison herd's long journey is coming to an end. They're close to the geyser basin. And now, for the first time the calf can see a land of fire. The warmth draws them in. The calf and his mother finally arrive. Day and night, scalding water erupts from the subterranean furnace. It can kill any animal that falls in. But for the herd it's a snow-free oasis. At last, they can eat. The grass is last season's, bu it does the job. This meal comes with a price. The geyser water deposits fine grains of silica all over the grass. Bison can live for twenty years, but this sandy grass may grind down their teeth in only twelve ...and then they'll starve to death. For the bison, these hot springs are both salvation... ...and curse. Their presence is felt throughout the park. All this hot water creates one of the most unique rivers systems in the world. Every second, over 500 gallons pours into Yellowstone's Firehole River, warming it by up to 18 degrees. So this river never freezes. It's a natural, warm sanctuary in a frozen world. The desperate otters are into their tenth mile. But finally... the sound of survival. The pup's hungry enough to catch his own fish. He's faced Yellowstone's dangers, and survived. He's ready to set out on his own. But maybe not just yet. Under the ice, the beaver family has weathered well through four months of winter. There's still plenty of food on the table... Which is good, 'cause Mom and dad have three new mouths to feed. Making it seven kids in all. They have worked hard for their success... But their victory is a part of a bigger picture that starts with the wolves Wolves hunt elk. Which means Elk may eat fewer of the beaver's trees. Successful beaver ponds are popular with trout Otters love trout. Fewer elk also means less competition for bison... ... Whose population is now thriving. Wolves spark an ecological chain reaction that benefits many who live here. But for it all to work... ...The wolves must do their job... ...Kill. The Dark wolf and her pack haven't eaten in days. But they have a target. A yearling... The Dark wolf drives the elk into deeper snow where she'll have the advantage. The others now know what to do. They choose their target well, The yearling is tiring. At last, the pack has learned how to hunt together. [BARKING-GROWLING] With this kill they've turned Yellowstone's savage winter into their ally. And with their success, all of Yellowstone will triumph... [SNORT-ROAR] NARRATOR: Yellowstone is heating up for battle. An explosion of energy. A test of power. [ROARING] [HEAD BUTTING] Welcome to Yellowstone's summer. [GEYSER ERUPTING SOUND] This should be the good times. But summer here has a dark side. That punishes the unprepared. And forces everyone to fight to survive. Its summer... ...and the game is on. High in the peaks of Yellowstone's super-volcano ... Predators are rising... Over 600 grizzly bears are advancing on greater Yellowstone This young male has been asleep for months. And he's hungry. It's a big summer. His first without mom... ...His first fending for himself. And winning a place at Yellowstone's table is not easy During winter, Cougars and Wolves run the show. But power can shift when seasons change... His mom taught him... if you follow wolves... They lead you to food. It's one thing to follow... Another to fight. [RAVENS SOUND] He should easily dominate a couple wolves. [HOWLING WOLF] But reinforcements are coming. The wolves keep control. But the bear will be back. First... he needs to build his strength. To do that, a bear needs food. There's always something to eat in Yellowstone. He just has to remember where to find it. What, is that? Sounds like... breakfast! Should be easy enough... Sniffing them out... Is harder than it sounds. But rodents are barely appetizers. Summer is short. He needs to fatten up fast. His life depends on it. By May, eight months of snow is poised to crash into the world below... [AVALANCHE SOUND] Ready or not... summer is here. Yellowstone transforms... with the melt. Rivers swell by 18 times. More than 3 million gallons a minute roars over Lower Yellowstone Falls. [SPLASHING SOUND] This much water... makes waves. Downstream... A beaver dad takes his turn maintaining the lodge as his family has for generations. Inside, he and mom have three new-bornS. This pond is everything they have. But Mom senses trouble. Millions of tons of water are roaring their way. The lodge is designed to withstand a flood. But everything has a breaking point. If the lodge collapses... the kits could die. The dam is breeched. Their pond - draining. But the lodge... holds strong. ...the family survives. But without a pond, they won't live, to see another summer. All this water... kick-starts an explosion of life. Summer is hard on the young. But they don't know that yet. Many of the animals born here will never turn one. It's up to their parents to keep them alive. To wolves... that means killing. This Mom... means business. The swollen river saves the elk's life. Now, she's cold... wet... ...and still hungry. In summer, even meadows become killing fields. The grizzly's mother brought him here when he was young. He's back because he remembers today's menu features his favorite dish. Baby elk. Available for a short time only. In three weeks this young calf will be able to outrun the bears Until then, his only chance... Hide. The bear knows something's here. The mother elk tries to draw him away... If the calf panics... it's all over. It's a lethal game... ...of hide... ...and seek. NARRATOR: The young elk must be perfectly still. [HEART BEAT SOUND] The young grizzly picks up a trail. Don't... move... a muscle. The bear misses, because the young elk has almost no scent. Another failed opportunity. They'd better get moving. The bear will be back. [SOUND OF RUSHING WATER] This stream will hide their trail. The water is still high. Just one wrong step... [BABY ELK SOUND] The calf is gone. He survives a bear hunt... Yellowstone takes him anyway. Summer can be brutal and benevolent. A potent cocktail of water and sun triggers Yellowstone's bloom. Filled with nectar... for a special guest... from a thousand miles away. This hummingbird flies all the way from Mexico... for Yellowstone's sweet nectar. Her extra-long tongue can reach the riches at the back of the flower. Beating her wings 60 times a second uses up a lot fuel. She drinks her bodyweight every day. So she'll fight... for her flowers. A nectar thief! [BIRDS SOUND] Back off... These are her flowers. At just a tenth of an ounce... she's one bad little bird. Yellowstone's bloom is a window of opportunity for many. This black bear is after fresh grass. Eat up, while it's young... These greens are the most tender for the first few weeks. While mom feeds, her cubs explore... ...and play. [CUBS BEAR SOUND] Climbing will come... ...with practice. Dinnertime. Cubs fatten up quick. No one percent milk for these guys. Mom's milk is 25 percent fat. But something is coming... A hungry male black bear... Mom knows he will kill and eat her cubs. The tree is their emergency exit. But male bears can climb too... [ROARING BEARS] Mom... has no choice. She must fight. NARRATOR: The cubs climb for their lives. Their mother will risk hers to defend them. The male crosses a line. She responds with a mother's fury. He's much bigger... but she has much more to lose. [ROARING-GROWLING BEARS] Her cubs are safe. The big tree provides an easy escape... And they've got one tough mother. As the summer sun heats up, high waters recede. Once dangerous rivers... now, offer opportunity. Warm water flips a switch in cutthroat trout... it's time to spawn. Across Yellowstone hundreds of thousands are on a voyage, back to where they were born. This male has come 100 miles... His final leg, a steep climb higher into the mountains. At last. A warm, quiet place to spawn. Soon... the first female appears... She digs a space in the streambed... and releases thousands of eggs. Which the male promptly fertilizes. After all this... the eggs journey begins with a massacre. [DUCK SOUND] But enough will make it. For the adults... Some will do this again next year. If they can make it out alive... The river otter loves trout. [SPLASHING WATER SOUND] One of the most calorie-packed foods in all of Yellowstone. For this trout, the game is over. By late summer... the sun, so welcome months ago... Bakes the land without mercy. Even boiling geyser basins begin to dry... Mud pools thicken. ...and explode. Yellowstone's relentless sun... Changes the game again. As the caldera heats up... so do the bison. [BISON CALL] Bull testosterone doubles. Their tempers flare. Yellowstone's behemoths are about to erupt. Now... the hot valley floor becomes the arena for the biggest fight of the summer. NARRATOR: This one-ton bison bull has one thing on his mind. He's a stud in this herd. And wants to keep it that way. His problem? There are too many ladies. With several female in estrous, he must defend multiple fronts. But it's not a harem. These females aren't his. When they're ready, they'll mate with any big male around. He needs to make sure that's him. There are dozens of love blind males-looking to score. The big male must scare them off... Some bulls don't get the message. He easily bests most challengers... But his next fight is always waiting. Another victory... and another battle. He'll go multiple rounds every day... ...Running a marathon between bouts. He'll do this every day... for a month. The price of being number one. During his reign, he'll mate with several cows. But the rut will exhaust him. By the end... the big bull is broken. He hasn't eaten much in weeks... And he's lost 200 pounds. His heart... gives out. He got what he wanted. His bloodline is secure. But he paid the ultimate price. His body won't go to waste... Across the park, the young grizzly is after a different meal. He's had a rough summer... and he's not nearly fat enough to survive the winter. His hunger drives him two miles high into the mountains. Where his mother once showed him a hidden treasure. Hiding in the rocks... millions of juicy moths escape the heat. Each one is 70 percent fat... He will eat tens of thousands... if he can. But his secret is out. Fights over food... turn ugly quick. NARRATOR: The desperate grizzly tries to put off the trespassing bears. But mother bears are hard to deter. [GROWLING-ROARING BEARS] Hungry, tired, and now beaten up by a girl... he's not welcome here. Another loss for the young bear. Nothing in Yellowstone is easy. It's been 3 months since the beaver pond was destroyed. Mom and dad have been working around the clock. It's dad's turn... to work the night shift. Evenings are a cool time to get stuff done. He's a beaver out of water... So he must work quickly... Dangerous things go bump in the night. [HOWLING SOUND] [BARKING] Hmmm. Coast is clear. Finally. But watch out... [BREAKING TREE SOUND] This tree has enough branches to finish the job. A few final touches, and the dam is complete. It's taken all summer... but the beaver's pond is finally full. Their masterpiece will help keep the family alive through winter. As summer fades and temperatures drop... urgency rises. Shorter days trigger the final big event of the summer... A dangerous battle of skills. Dozens of seven hundred pound elk stags have come out of the woodwork... Ready to face off... [ELK BUGLING] ...with song. The prize... a harem. The female judges listen with a critical ear. Win their vote and they join your harem. The first contestant... Weak. Lesser males are easy to identify... by their feeble songs. The big stag is up next. His song is stronger... Approving cows vote with their feet ...And leave weaker males. The Next contestant... He's just as strong. And steals several cows from the other stag. But no big bull worth his bugle willingly gives up his harem. Now the two tenors face off... This voice competition is about to become a knife fight. NARRATOR: The stag elk's antlers have grown half an inch a day for months... Just for this moment. An elk battle is as much about technique as brute force. Most fights only last seconds. But six minutes in, neither stag is giving up. Finally, the old man runs the challenger off. And claims his harem. His legacy will carry down to thousands of descendants. In this final game of summer, winner takes all. The winter wind announces summer's last call. It's been a difficult season for the young bear. He needs a final meal... His mortal enemies... have one. He was chased off a kill by this wolf pack at the start of summer. But he's stronger and wiser... and ready to try again... When out of nowhere a bigger bear beats him to it. The big male is aggressive. The wolves... relentless. Bravely... the young male moves in. [GROWLING BEAR] The wolves force the big male out. The young bear tries a surprising tactic. Stay calm... [GROWLING WOLVES] Steady... It's cool... [GROWLING WOLF] By coming in peace, he secures himself a big meal. He's learned a lot this summer... ...and he's finally ready for winter... All bears must make the most of summer. There will be nothing left for them down here. And then, it will be time to den. The young male climbs high into the mountains. To a steep, north slope. In just hours, summer will be a memory. Covered for months by 30 feet of snow. On the other side, Yellowstone's summer will be waiting.