0:00:03 > 0:00:08Meet Sam, Sophie and Sybil, three black bear cubs.
0:00:10 > 0:00:14They live with their mum, Juliet.
0:00:14 > 0:00:18They're just three months old, tiny and vulnerable.
0:00:18 > 0:00:21They rely entirely on Mum for survival.
0:00:24 > 0:00:28I spent May in the Northwoods of Minnesota for Planet Earth Live...
0:00:28 > 0:00:31BEAR GRUNTS
0:00:31 > 0:00:34..following the cubs as their story unfolded.
0:00:35 > 0:00:38- SHE WHISPERS - And so vulnerable.
0:00:38 > 0:00:40Just...oh, God...just so sweet.
0:00:40 > 0:00:44These woods are full of danger and challenges.
0:00:47 > 0:00:49Savage cold.
0:00:49 > 0:00:52Weather that can turn in an instant.
0:00:52 > 0:00:54Deadly predators.
0:00:54 > 0:00:58Eagles, coyotes, wolves.
0:00:58 > 0:01:02- And even forest fires. - SIRENS WAIL
0:01:06 > 0:01:10Mum, Juliet, has a battle on her hands to keep her three cubs safe.
0:01:12 > 0:01:16This is Sam, Sophie and Sybil's story.
0:01:43 > 0:01:45The cubs are born in mid-January.
0:01:50 > 0:01:54The bears are all deep in hibernation.
0:01:54 > 0:01:56Many females are pregnant.
0:01:58 > 0:02:02They mated last year, fattened up in autumn,
0:02:02 > 0:02:06and settled in their dens around September.
0:02:06 > 0:02:11In January, temperatures can drop as low as -20 degrees Celsius.
0:02:11 > 0:02:16The woods are buried under almost a metre of snow.
0:02:23 > 0:02:28The females must conserve energy just to get through the winter.
0:02:28 > 0:02:32And to give birth.
0:02:37 > 0:02:39In mid January, mum, Juliet
0:02:39 > 0:02:43welcomes Sam, Sophie and Sybil into the world.
0:02:46 > 0:02:49BEARS CHATTER
0:02:49 > 0:02:53Black bear cubs are born blind and helpless.
0:02:53 > 0:02:56They each weigh less than half a kilogram.
0:03:00 > 0:03:02The den is like a second womb.
0:03:02 > 0:03:04It keeps them safe as they grow.
0:03:15 > 0:03:17By around six weeks, their eyes are open,
0:03:17 > 0:03:20and they've begun to crawl and explore.
0:03:28 > 0:03:30Usually, they leave the den in May.
0:03:30 > 0:03:34By then, they'll weigh ten times more than when they were born.
0:03:42 > 0:03:46But in April, things go badly wrong for Sam, Sophie and Sybil.
0:03:52 > 0:03:57Juliet's den is in a low-lying cedar bog.
0:03:57 > 0:04:00Normally, the ground would stay frozen
0:04:00 > 0:04:04until the cubs were ready to leave.
0:04:04 > 0:04:07But spring this year is incredibly warm.
0:04:07 > 0:04:10The snow begins to melt over a month earlier than usual.
0:04:12 > 0:04:15WATER RUSHES
0:04:20 > 0:04:23The den slowly fills with icy meltwater.
0:04:25 > 0:04:28Juliet must evacuate her cubs.
0:04:38 > 0:04:41For the triplets, this is the equivalent of a premature birth.
0:04:45 > 0:04:48They're fragile and exposed.
0:04:48 > 0:04:51Juliet must make a life or death decision.
0:05:00 > 0:05:04She can wait by the den and hope that the water refreezes,
0:05:04 > 0:05:08or move the tiny cubs to another site to see out the winter.
0:05:17 > 0:05:19For the cubs, a wrong choice could be fatal.
0:05:25 > 0:05:28Little Sybil is especially vulnerable.
0:05:28 > 0:05:30She's the smallest and the weakest.
0:05:33 > 0:05:34Her eyes have barely opened.
0:05:34 > 0:05:37She hardly has the energy to move.
0:05:43 > 0:05:46But Juliet's made her decision.
0:05:46 > 0:05:49She's ten years old, an experienced mother.
0:05:49 > 0:05:52She must find somewhere else to keep the cubs safe.
0:05:58 > 0:06:02After five months with no food, this journey is exhausting for her.
0:06:06 > 0:06:10For her tiny cubs, it's an almost unimaginable effort.
0:06:25 > 0:06:29Finally, Juliet finds a spot.
0:06:30 > 0:06:33She uses this as a day bed in the summer.
0:06:33 > 0:06:37The overhanging branches will keep off the worst of the weather.
0:06:42 > 0:06:45Fresh foliage makes the bed as comfortable as possible.
0:06:45 > 0:06:47But there's not much about.
0:06:54 > 0:06:57Exhausted, she collapses.
0:06:57 > 0:07:00And the cubs enjoy a well-earned meal in their new home.
0:07:00 > 0:07:03CUBS CHATTER
0:07:10 > 0:07:13Juliet's decision has paid off.
0:07:13 > 0:07:15For now.
0:07:26 > 0:07:29Minnesota is nestled up on the Canadian border.
0:07:29 > 0:07:32The state of 10,000 lakes.
0:07:34 > 0:07:36In between the lakes are the Northwoods,
0:07:36 > 0:07:42a mixed woodland of pines, firs, cedars and aspen.
0:07:47 > 0:07:50It's home to over 20,000 black bears.
0:08:00 > 0:08:06Biologist Lynn Rogers has studied the bears here for over 45 years.
0:08:06 > 0:08:12He's developed some controversial and revolutionary methods.
0:08:16 > 0:08:23For years, Lynn tranquilised bears to fit radio collars and track them.
0:08:23 > 0:08:24Then he found a new a way.
0:08:24 > 0:08:27He uses treats to gain the bears' trust.
0:08:27 > 0:08:29No more tranquilisers.
0:08:34 > 0:08:38It's good for the bears, and good for Lynn, too.
0:08:40 > 0:08:43He and his researchers can now walk with the bears
0:08:43 > 0:08:47and learn from them as they go about their daily lives.
0:08:47 > 0:08:50BEAR SNIFFS
0:08:56 > 0:08:59Thanks to his work, we can get these incredibly close
0:08:59 > 0:09:02and intimate views of black bears.
0:09:15 > 0:09:19When I arrived at the start of May, I was desperate to experience
0:09:19 > 0:09:22some of these intimate views for myself.
0:09:25 > 0:09:27I wanted to see how Sam, Sophie and Sybil were doing,
0:09:27 > 0:09:29after their traumatic start to life.
0:09:35 > 0:09:38Lynn took me straight out into the woods to find them.
0:09:38 > 0:09:41TRACKER CLICKS
0:09:41 > 0:09:43Let's see if she's there.
0:09:47 > 0:09:48That way.
0:09:50 > 0:09:53'I have to admit, I was nervous.
0:09:53 > 0:09:56'It's not every day you walk up to a completely wild black bear
0:09:56 > 0:09:57'with no protection.'
0:10:01 > 0:10:03Let's see if she's there. Ah-ha!
0:10:03 > 0:10:06I'm sorry, bear! I rushed up upon you!
0:10:06 > 0:10:10You might be a little bit brave being here.
0:10:10 > 0:10:14I've always heard, never get between a mother and her cubs,
0:10:14 > 0:10:17but it takes more than a mother black bear to scare us.
0:10:17 > 0:10:19Well, maybe it takes more to scare you,
0:10:19 > 0:10:23- because you've been doing this for 45 years! - THEY LAUGH QUIETLY
0:10:25 > 0:10:26It's interesting...
0:10:26 > 0:10:29- BEAR MOVES AND GRUNTS - Ooh! Oh, God!
0:10:29 > 0:10:30I'm sorry bear, what do you want?
0:10:32 > 0:10:34You wonder what we're here for?
0:10:35 > 0:10:40We think this is the only place in the world that we can come
0:10:40 > 0:10:43and see a mother with cubs like this, have her sit and trust us.
0:10:43 > 0:10:46- A WILD bear. Let's remember this. - Yeah, yeah.
0:10:51 > 0:10:52Mmm-hmm.
0:10:52 > 0:10:54Mmm-hmm. Mmm-hmm.
0:10:54 > 0:10:55Hello, Mrs Bear.
0:10:57 > 0:11:00Nothing from me, I'm afraid.
0:11:00 > 0:11:02BEAR HISSES
0:11:02 > 0:11:03No.
0:11:03 > 0:11:05I MEAN no.
0:11:05 > 0:11:07SHE SIGHS
0:11:07 > 0:11:13These aggressive looking charges are called blusters.
0:11:13 > 0:11:15They don't mean the bear is about to attack.
0:11:15 > 0:11:17She's just nervous, probably because I'm new.
0:11:20 > 0:11:23- For me, this is scary stuff. - BEAR SNARLS
0:11:23 > 0:11:26But Lynn's been doing this for 45 years.
0:11:26 > 0:11:30He's been blustered thousands of times,
0:11:30 > 0:11:32and not once has a bear attacked him.
0:11:32 > 0:11:35BEAR THUMPS HIDE
0:11:38 > 0:11:40- SHE WHISPERS - Where are those cubs?
0:11:40 > 0:11:42They must be pretty high.
0:11:42 > 0:11:45I wish they'd come down. Yeah.
0:11:46 > 0:11:49'No cubs in sight. But Mum wasn't worried.
0:11:49 > 0:11:53'So we took our cue from her, and sat down to wait.
0:11:58 > 0:12:02'After 45 minutes, our patience paid off.'
0:12:07 > 0:12:10- SHE WHISPERS - Yeah, here we go.
0:12:10 > 0:12:13- OK.- Here we go.
0:12:13 > 0:12:15I've never seen anything so cute!
0:12:18 > 0:12:20'Sophie is bravest.
0:12:20 > 0:12:23'She's first to climb down to join mum.'
0:12:23 > 0:12:27- Oh!- She's got them to wake up.
0:12:36 > 0:12:40- SHE WHISPERS - I can't believe I'm actually sitting
0:12:40 > 0:12:45right here, just a few feet away from this...
0:12:45 > 0:12:50adorable, vulnerable, beautiful creature.
0:12:55 > 0:12:57Look, she's feeding.
0:12:57 > 0:13:02'A few minutes later, Sam puts in an appearance.'
0:13:02 > 0:13:04Someone else to join the party.
0:13:06 > 0:13:09Is he the right size for his age, or should he be bigger?
0:13:10 > 0:13:12He's doing OK, yeah.
0:13:12 > 0:13:13He's doing OK.
0:13:24 > 0:13:29'Finally, cautious little Sybil decides to join the family meal.'
0:13:29 > 0:13:31Oh!
0:13:35 > 0:13:38CUBS CHATTER
0:13:38 > 0:13:40They're starting to nurse.
0:13:40 > 0:13:41That little cheering hum.
0:13:41 > 0:13:43That's the sound of nursing?
0:13:43 > 0:13:47Yeah. That's the sound of a contented cub.
0:13:47 > 0:13:48A comfortable cub.
0:13:56 > 0:14:00Once the cubs have had their fill, it's time for a stretch,
0:14:00 > 0:14:02and then play time.
0:14:11 > 0:14:13BEARS YELP AND GROWL
0:14:13 > 0:14:16That's what you call a bear hug!
0:14:41 > 0:14:44As the exceptionally hot spring continues,
0:14:44 > 0:14:47more bears take advantage of the warmth
0:14:47 > 0:14:49to come out and forage.
0:14:56 > 0:14:58But it's still early in the season,
0:14:58 > 0:15:02and the bears are dangerously exposed.
0:15:08 > 0:15:10Jewel is a three-year-old,
0:15:10 > 0:15:11and a first-time mother.
0:15:14 > 0:15:17She has two cubs, Herbie and Fern.
0:15:20 > 0:15:22They're twins and inseparable.
0:15:28 > 0:15:31Jewel has a decision to make.
0:15:31 > 0:15:34Stay in the den, keeping the twins warm and safe,
0:15:34 > 0:15:36or go out in search of food.
0:15:40 > 0:15:43She hasn't eaten for six months.
0:15:43 > 0:15:44She's famished.
0:15:47 > 0:15:49She decides to leave the den,
0:15:49 > 0:15:51taking Herbie and Fern with her.
0:15:56 > 0:15:58She's a first-time mother,
0:15:58 > 0:16:03so her decision is based on instinct rather than experience.
0:16:03 > 0:16:06She has no way of knowing that the weather
0:16:06 > 0:16:10has another surprise in store for them.
0:16:12 > 0:16:15A cold front is approaching from the north,
0:16:15 > 0:16:17bringing howling Arctic winds.
0:16:18 > 0:16:20Winter has returned.
0:16:29 > 0:16:33For Jewel, for Juliet, and especially for their cubs,
0:16:33 > 0:16:36this could spell disaster.
0:16:39 > 0:16:43Juliet has the advantage of experience.
0:16:43 > 0:16:45As the snow starts to fall,
0:16:45 > 0:16:48she keeps her cubs close to her body
0:16:48 > 0:16:50so they benefit from her warmth.
0:17:01 > 0:17:03As they suckle, she helps keep them dry
0:17:03 > 0:17:05by licking the snow from their backs.
0:17:18 > 0:17:21Just a few miles away, first-time mum, Jewel, is struggling.
0:17:29 > 0:17:34She's stranded well away from her den with her cubs, Herbie and Fern.
0:17:40 > 0:17:43The cubs' first reaction is instinctive.
0:17:43 > 0:17:47They're faced with danger.
0:17:47 > 0:17:50There's only one thing to do.
0:17:50 > 0:17:52Herbie and Fern climb a tree.
0:17:55 > 0:17:58It's a potentially catastrophic tactic.
0:18:01 > 0:18:05Sticking closely together as always,
0:18:05 > 0:18:10soon, both cubs are shivering with cold.
0:18:14 > 0:18:17Up here, there's very little protection from the elements.
0:18:17 > 0:18:20Their coats are quickly crusted in snow.
0:18:26 > 0:18:32Down on the ground, their mother's body heat could help them keep warm.
0:18:32 > 0:18:37Up here, their small bodies are struggling to generate enough heat.
0:18:43 > 0:18:47They're shivering so hard they can barely hold on.
0:18:56 > 0:18:59Eventually, Jewel seems to understand the situation.
0:18:59 > 0:19:01She calls the cubs down.
0:19:01 > 0:19:05SHE CLICKS AND CALLS
0:19:15 > 0:19:17Herbie and Fern gingerly make their descent.
0:19:17 > 0:19:19It's slow going in the cold.
0:19:19 > 0:19:21A slip could kill them.
0:19:37 > 0:19:40Jewel urgently needs to get the cubs close, warm them up,
0:19:40 > 0:19:43and protect them from the storm.
0:19:55 > 0:19:58But incredibly, instead she moves off,
0:19:58 > 0:20:02leaving her frozen youngsters to struggle after her.
0:20:05 > 0:20:08CUBS SQUEAL
0:20:09 > 0:20:11At just three months old,
0:20:11 > 0:20:13the cubs find walking on snow almost impossible.
0:20:15 > 0:20:19Their paws are just too small, and sink into the drifts.
0:20:26 > 0:20:28With the snow now deeper than the cubs are tall,
0:20:28 > 0:20:31this is a dangerous world.
0:20:36 > 0:20:40Worse, the cubs only have a single layer of fur.
0:20:40 > 0:20:44They won't grow a second, insulating layer
0:20:44 > 0:20:46until they go into hibernation in the autumn.
0:20:51 > 0:20:55But autumn is a long way off for Herbie and Fern.
0:20:57 > 0:20:59Without Jewel, they won't last the night.
0:21:03 > 0:21:07But as darkness falls, there's still no sign of her.
0:21:09 > 0:21:13Overnight, the temperature plummets to -12 degrees Celsius.
0:21:13 > 0:21:16There's little hope the cubs will survive.
0:21:22 > 0:21:24But as dawn breaks...
0:21:25 > 0:21:27..relief.
0:21:40 > 0:21:43Jewel hasn't abandoned the cubs.
0:21:43 > 0:21:46She's led them to safety.
0:21:46 > 0:21:49She's found a more sheltered spot.
0:21:55 > 0:21:58Now she's keeping Herbie and Fern close and warm.
0:22:16 > 0:22:21The snow storm has highlighted the difference that experience can make.
0:22:26 > 0:22:28Jewel struggled in the storm,
0:22:28 > 0:22:32though ultimately, her instincts were good.
0:22:32 > 0:22:34But with three sets of cubs behind her,
0:22:34 > 0:22:37Juliet has taken it in her stride.
0:22:45 > 0:22:48So far this year, she's got everything right.
0:22:48 > 0:22:49Her cubs are growing well,
0:22:49 > 0:22:52and developing personalities of their own.
0:22:59 > 0:23:03Sam, the lone boy, is boisterous and adventurous.
0:23:09 > 0:23:11He's always on the look out for a scrap,
0:23:11 > 0:23:14usually with the middle sister, Sophie.
0:23:20 > 0:23:22But Sophie isn't afraid to fight back.
0:23:22 > 0:23:27In fact, the two of them are almost inseparable.
0:23:36 > 0:23:37Which means that Sybil,
0:23:37 > 0:23:39the smallest and most vulnerable cub,
0:23:39 > 0:23:40is often left out.
0:23:43 > 0:23:46She's smaller and skinnier than the other two.
0:23:46 > 0:23:49That puts her most at risk.
0:23:55 > 0:23:58But without a den to protect them,
0:23:58 > 0:24:02all the cubs are extremely vulnerable.
0:24:02 > 0:24:07They'd make a tasty snack for any of the Northwoods' many predators.
0:24:15 > 0:24:17These woods are rich hunting grounds.
0:24:17 > 0:24:20There's plenty of potential prey.
0:24:24 > 0:24:26A camera trap baited with a deer carcass
0:24:26 > 0:24:29exposes some of the threats the cubs face.
0:24:29 > 0:24:32CROWS CAW
0:24:32 > 0:24:35The crows are first to arrive,
0:24:35 > 0:24:39but their meal is soon disturbed.
0:24:42 > 0:24:43A bald eagle.
0:24:48 > 0:24:50They're immensely powerful,
0:24:50 > 0:24:53easily strong enough to snatch and kill a cub.
0:24:58 > 0:25:01But the biggest threats come out at night.
0:25:09 > 0:25:13A red fox. Small but wily.
0:25:13 > 0:25:15It could easily sneak up and grab a cub.
0:25:22 > 0:25:23Coyotes are much larger.
0:25:23 > 0:25:26For them, a bear cub is fair game.
0:25:31 > 0:25:34Finally, the most dangerous of all.
0:25:34 > 0:25:37A grey wolf.
0:25:43 > 0:25:46There are around 3,000 wolves in Minnesota.
0:25:54 > 0:25:59It's rare for a pack to attack a mother bear with cubs.
0:25:59 > 0:26:01But if they find Sam, Sophie and Sybil alone,
0:26:01 > 0:26:04our little friends won't stand a chance.
0:26:17 > 0:26:20Luckily, bear cubs have a survival trick all of their own.
0:26:25 > 0:26:29From the moment they leave the den, black bears can climb.
0:26:38 > 0:26:41But when you're tiny, nothing is as easy as it looks.
0:26:45 > 0:26:48One major challenge is working out
0:26:48 > 0:26:50which trees are safe to scamper up.
0:26:50 > 0:26:52Some are better than others.
0:26:57 > 0:26:59This beauty is a red pine.
0:26:59 > 0:27:00It's a nice mature tree,
0:27:00 > 0:27:04and it looks as if it should be a good climber, but it's not.
0:27:04 > 0:27:07Because the bark just peels away,
0:27:07 > 0:27:10so the little claws would dig in...
0:27:12 > 0:27:15..and then fall away.
0:27:19 > 0:27:20So we've got a paper birch
0:27:20 > 0:27:22right next door to a cedar here.
0:27:22 > 0:27:25I'll show you why this is called the paper birch.
0:27:25 > 0:27:27Look at that. So, not a great climbing tree,
0:27:27 > 0:27:31and also quite slippy.
0:27:31 > 0:27:34The cedar, on the other hand,
0:27:34 > 0:27:35nice juicy, juicy trunk,
0:27:35 > 0:27:38and you can get really good purchase on that.
0:27:38 > 0:27:40That's a good climber.
0:27:45 > 0:27:47And finally, this is actually
0:27:47 > 0:27:50the perfect black bear climbing tree,
0:27:50 > 0:27:51a mature white pine.
0:27:51 > 0:27:55Look at the bark. Very sturdy and solid.
0:27:55 > 0:27:57It doesn't come away at all.
0:27:57 > 0:28:00So, imagine claws clinging into that.
0:28:00 > 0:28:03And then, when you go up to the top, plenty of protection,
0:28:03 > 0:28:05strong, sturdy branches, and protection
0:28:05 > 0:28:08from the rain and from the sunshine for the cubs.
0:28:08 > 0:28:13And you can see how protected you would be down here.
0:28:13 > 0:28:15This is actually one of Juliet's day beds.
0:28:15 > 0:28:19And look, it's been raining all morning... Perfectly dry.
0:28:21 > 0:28:23Of course, it doesn't matter what kind of tree it is
0:28:23 > 0:28:25if it's far too small.
0:28:29 > 0:28:31Or if it's dead.
0:28:33 > 0:28:35And even on the big trees,
0:28:35 > 0:28:37the tough bit's getting down.
0:29:24 > 0:29:27CUB YELPS
0:29:37 > 0:29:39It's exhausting work for little legs.
0:29:39 > 0:29:41But the cubs are bundles of energy,
0:29:41 > 0:29:44and play is an important part of growing up.
0:29:44 > 0:29:47CUBS YELP
0:29:47 > 0:29:50Sam and Sophie play fight constantly.
0:29:56 > 0:29:59These battles teach coordination, build muscle,
0:29:59 > 0:30:01and establish a pecking order among the cubs.
0:30:03 > 0:30:05Little Sybil tries to join in the fun,
0:30:05 > 0:30:09but Sam and Sophie quickly reject her.
0:30:13 > 0:30:16She's bottom of the pecking order,
0:30:16 > 0:30:18even when the cubs are suckling.
0:30:23 > 0:30:26Female black bears have three pairs of nipples.
0:30:26 > 0:30:32The top pair provide more rich milk than the lower two pairs.
0:30:32 > 0:30:35Thanks to their play fights, Sam and Sophie are stronger.
0:30:35 > 0:30:38They always get the best meal.
0:30:38 > 0:30:40CUBS CHATTER
0:30:43 > 0:30:45When Sybil tries to barge in,
0:30:45 > 0:30:47Sam bullies her into submission.
0:30:53 > 0:30:56In this fight, it's every cub for themselves.
0:31:00 > 0:31:02One in five cubs die in their first year.
0:31:04 > 0:31:06Sybil is very much at risk.
0:31:16 > 0:31:19Having three cubs improves Juliet's chances as a mum.
0:31:19 > 0:31:24She may lose one, but two survivors is still a good year.
0:31:24 > 0:31:28If all three survive, even better.
0:31:28 > 0:31:32It all depends on whether Juliet can provide enough milk.
0:31:36 > 0:31:39The milk's around 25% fat,
0:31:39 > 0:31:42five times as rich as a cow's.
0:31:42 > 0:31:45Producing it is a strain on Juliet's reserves.
0:31:49 > 0:31:51To provide enough milk for three,
0:31:51 > 0:31:53she must eat whenever she gets the chance.
0:32:07 > 0:32:10But in these woods, it's tough to find enough food.
0:32:15 > 0:32:19Lynn took me out to show me some items on the Black Bear menu.
0:32:19 > 0:32:22If I were a bear coming along here
0:32:22 > 0:32:25and there's ant pupae about,
0:32:25 > 0:32:27I'd be sniffing this rock.
0:32:27 > 0:32:28And if I smelled something,
0:32:28 > 0:32:31I'd pull it over and be licking up
0:32:31 > 0:32:34all the pupae and the larvae.
0:32:36 > 0:32:37OK, nothing there, though.
0:32:37 > 0:32:41They don't roll them back, but I do. JULIA LAUGHS
0:32:41 > 0:32:43These look like juicy little morsels. What are they?
0:32:43 > 0:32:47Oh, large leaf aster, and bears are eating those right now.
0:32:47 > 0:32:50They only eat them when they're in this fuzzy stage, all curled up.
0:32:50 > 0:32:53- This is when they taste good. - Right.
0:32:54 > 0:32:56- Tastes OK.- OK.
0:32:56 > 0:32:59- And here's something else right now.- What's that?
0:32:59 > 0:33:01HE LAUGHS Horse tail.
0:33:01 > 0:33:02What does that taste like?
0:33:02 > 0:33:05Not that good. SHE LAUGHS
0:33:07 > 0:33:08Oh, here.
0:33:08 > 0:33:11Here's something a bear would check for grubs.
0:33:11 > 0:33:13They just tear into it like that.
0:33:13 > 0:33:15And what sort of grubs are we looking for?
0:33:15 > 0:33:18Beetle larvae.
0:33:18 > 0:33:21But they would know if there's grubs in here.
0:33:21 > 0:33:25They sniff it first, before they waste the energy.
0:33:25 > 0:33:28They know their stuff, these bears, don't they?
0:33:28 > 0:33:30Yeah! Yep.
0:33:30 > 0:33:32So here's an aspen tree,
0:33:32 > 0:33:34and if a bear was going to eat the leaves,
0:33:34 > 0:33:38- which they eat at this time of the year...- Yeah.
0:33:38 > 0:33:40..they climb it and bring the tree down
0:33:40 > 0:33:43and then they would strip the leaves
0:33:43 > 0:33:44through their mouth...
0:33:45 > 0:33:48SHE LAUGHS ..sideways, like that.
0:33:50 > 0:33:54- Good bear! - Yuck, I got the whole thing!
0:33:54 > 0:33:55Shall we let this tree live?
0:33:55 > 0:33:57- Yes.- OK, I'm going to let it go.
0:33:57 > 0:33:58- OK.- OK?- Yeah.
0:33:58 > 0:34:00There we go.
0:34:06 > 0:34:08As spring warms the woods,
0:34:08 > 0:34:10more food begins to appear.
0:34:17 > 0:34:21For Sam, Sophie, and Sybil, it's an important time.
0:34:21 > 0:34:24They need to investigate all these foods for themselves.
0:34:29 > 0:34:32Because exactly a year from now, when they're yearlings,
0:34:32 > 0:34:35Juliet will kick them out to face life alone in the woods.
0:34:44 > 0:34:47It's called family break up, and it's driven by one thing.
0:34:47 > 0:34:50The need to mate.
0:34:57 > 0:35:01Every year in May, the normally secretive males reappear.
0:35:04 > 0:35:06They're looking for receptive females
0:35:06 > 0:35:09and they'll fight to get access to them.
0:35:15 > 0:35:19Males are hugely powerful. They can weigh up to 275 kilograms.
0:35:21 > 0:35:23Fights like this can cause serious harm.
0:35:27 > 0:35:29You might expect them to roar.
0:35:29 > 0:35:30Instead, they honk.
0:35:32 > 0:35:35BEARS HONK
0:35:49 > 0:35:51For yearlings with receptive mothers,
0:35:51 > 0:35:53the message is brutal and clear.
0:35:54 > 0:35:56Beware.
0:35:59 > 0:36:01Mum wants to mate.
0:36:01 > 0:36:03She doesn't want cubs around.
0:36:03 > 0:36:05Neither will the male.
0:36:10 > 0:36:11But breaking up can be difficult.
0:36:13 > 0:36:15Meet Aster and Aspen,
0:36:15 > 0:36:18yearlings born to mother, June, last January.
0:36:20 > 0:36:23At 18 months old, they're typical teenagers.
0:36:23 > 0:36:27Boisterous, troublesome, but not yet independent.
0:36:32 > 0:36:35Aster, the female, sticks close to mum.
0:36:39 > 0:36:41She's gentle and inquisitive,
0:36:41 > 0:36:45and still learning the tricks and trades of the woods.
0:36:45 > 0:36:47Not always successfully.
0:36:47 > 0:36:49Here she's come unstuck with red ants.
0:36:53 > 0:36:56The male cub, Aspen, is more independent.
0:36:56 > 0:36:58He's happy to head off on his own,
0:36:58 > 0:37:02sometimes for hours on end.
0:37:11 > 0:37:14But most of the time, both are content to stay close to June.
0:37:19 > 0:37:21But she has other ideas.
0:37:32 > 0:37:34June snaps, and Aspen is expelled.
0:37:43 > 0:37:46This is the reality of family break up.
0:37:48 > 0:37:51Aspen must now fend for himself,
0:37:51 > 0:37:53and face the dangers of the woods alone.
0:38:11 > 0:38:14But June still has Aster tagging along.
0:38:14 > 0:38:15Rather than drive her away,
0:38:15 > 0:38:17she tries to shake her off.
0:38:21 > 0:38:25When Aster moves ahead, June makes her move.
0:38:34 > 0:38:38When Aster realises she's alone, she backtracks.
0:38:38 > 0:38:40She clearly doesn't want to be left alone.
0:38:47 > 0:38:49Aster's going to be hard to shake.
0:38:49 > 0:38:51June needs a new tactic.
0:38:55 > 0:38:59Black bears have an incredible sense of smell.
0:38:59 > 0:39:03Maybe June can lose Aster by hiding her scent trail.
0:39:10 > 0:39:12But, persistent as ever,
0:39:12 > 0:39:14Aster is in hot pursuit.
0:39:23 > 0:39:26For now, June will have to put up with her daughter.
0:39:33 > 0:39:35At least she's down to one.
0:39:35 > 0:39:37Or so she thought.
0:39:53 > 0:39:56An unexpected visitor.
0:39:56 > 0:39:58Aspen rejoins the party.
0:40:00 > 0:40:01After two days out on his own,
0:40:01 > 0:40:04he's found his mum and sister again.
0:40:06 > 0:40:09It's unusual for a bear to return after break up.
0:40:11 > 0:40:14But instead of chasing him off again,
0:40:14 > 0:40:16June seems to accept his presence.
0:40:18 > 0:40:21And Aspen tries his hardest to ingratiate himself
0:40:21 > 0:40:22back into the fold.
0:40:36 > 0:40:39As June's yearlings struggle to accept their independence,
0:40:39 > 0:40:43Juliet's young cubs are in danger of embracing it too early.
0:40:49 > 0:40:53To provide milk for three hungry cubs, Juliet needs to feed.
0:40:57 > 0:40:59There are no babysitters in these woods.
0:40:59 > 0:41:03So she encourages Sam, Sophie and Sybil up a tree to keep them safe.
0:41:13 > 0:41:14Left home alone,
0:41:14 > 0:41:18it isn't long before the little bears start to misbehave.
0:41:20 > 0:41:24Sophie and Sam quickly get bored of waiting and decide to explore.
0:41:33 > 0:41:35Adventures are fun, but the woods are full of dangers,
0:41:35 > 0:41:38and it's easy to get lost.
0:41:55 > 0:41:59They climb a tree some distance from where Juliet left them.
0:41:59 > 0:42:00They're out of sight.
0:42:08 > 0:42:10Back by the first tree, Sybil is torn.
0:42:13 > 0:42:19She's unsure whether to follow her siblings or wait for Mum.
0:42:30 > 0:42:32She's alone on the forest floor,
0:42:32 > 0:42:34exposed and very vulnerable.
0:42:37 > 0:42:39She calls for help.
0:42:39 > 0:42:43SHE SQUEALS
0:42:52 > 0:42:57Juliet returns to find Sybil alone and distressed, but safe.
0:43:02 > 0:43:04There's no sign of Sam and Sophie.
0:43:13 > 0:43:16Juliet is faced with a dilemma. Rush off to look for them,
0:43:16 > 0:43:19or wait by the tree where she left them.
0:43:21 > 0:43:24SHE CALLS
0:43:24 > 0:43:28She calls, but the cubs are either out of range,
0:43:28 > 0:43:30or wilfully ignoring her.
0:43:38 > 0:43:40Suddenly, they reappear
0:43:40 > 0:43:43in a blur of black fur.
0:43:45 > 0:43:50They race back towards Mum, and are safely reunited.
0:43:50 > 0:43:54Clearly, these cubs are not yet as grown-up as they think they are.
0:44:20 > 0:44:24Meanwhile, our camera trap has picked up its first male.
0:44:31 > 0:44:33He's small and relatively immature,
0:44:33 > 0:44:37but his arrival signals the start of the breeding season.
0:44:37 > 0:44:40He's here for females, and the females are ready.
0:44:48 > 0:44:53When a female comes into season, she needs to advertise her availability.
0:44:53 > 0:44:56For black bears, that means scent marking.
0:44:59 > 0:45:03There are three good ways to leave your mark in these woods.
0:45:03 > 0:45:06First, tree rubbing.
0:45:08 > 0:45:10You need to choose a good, prominent tree.
0:45:10 > 0:45:15And then it's all about working hard to cover it in scent.
0:45:20 > 0:45:22A small bite finishes the job,
0:45:22 > 0:45:25and it's on to the second technique.
0:45:25 > 0:45:28Cowboy walking.
0:45:28 > 0:45:30Females have glands on their feet,
0:45:30 > 0:45:33and rubbing each foot into the ground leaves a trail
0:45:33 > 0:45:35for any prospective suitor.
0:45:46 > 0:45:48The final method is a messy one.
0:45:48 > 0:45:50Urinating.
0:45:52 > 0:45:54They drag themselves over small trees
0:45:54 > 0:45:56to leave a trail all across their territory.
0:46:00 > 0:46:01Not very appealing to us,
0:46:01 > 0:46:04but irresistible to male bears.
0:46:09 > 0:46:13And it seems that our male from the camera trap
0:46:13 > 0:46:14has picked up a scent,
0:46:14 > 0:46:16and found himself a female.
0:46:22 > 0:46:24Due to his small size,
0:46:24 > 0:46:26this male wouldn't normally have a chance to mate.
0:46:29 > 0:46:31This female seems impatient,
0:46:31 > 0:46:34and our male doesn't have to be asked twice.
0:46:45 > 0:46:50His small size causes a few logistical problems.
0:46:50 > 0:46:54But with persistence and the odd leg up,
0:46:54 > 0:46:56finally, he succeeds.
0:47:12 > 0:47:16Mating over, the female grooms the young male.
0:47:20 > 0:47:24With no yearlings around, she can afford to spend time with her man.
0:47:46 > 0:47:48There's no such luck for June.
0:47:48 > 0:47:52She's still got Aster and Aspen in tow.
0:47:54 > 0:47:56At least she can continue giving her yearlings
0:47:56 > 0:47:58the benefit of her experience.
0:48:03 > 0:48:06But experience doesn't always pay.
0:48:11 > 0:48:13There may be rich pickings along these verges,
0:48:13 > 0:48:16but foraging here puts our bears at risk.
0:48:16 > 0:48:18TRAFFIC RUMBLES
0:48:40 > 0:48:4380% of bear deaths in Minnesota are caused by man.
0:48:46 > 0:48:47Motor collisions,
0:48:47 > 0:48:50the killing of nuisance bears...
0:48:52 > 0:48:54..and hunting.
0:48:55 > 0:48:57SHOT FIRES
0:49:01 > 0:49:03Lynn has seen scores of bears
0:49:03 > 0:49:06killed or injured by humans in his 45 years here.
0:49:11 > 0:49:14When he takes a call saying a collared bear had been found,
0:49:14 > 0:49:17he immediately fears the worst.
0:49:20 > 0:49:22One of the bears he works with has been shot.
0:49:43 > 0:49:45This is Jo. She was obviously shot.
0:49:45 > 0:49:49See the blood on her tongue. There's a spot of blood up there.
0:49:49 > 0:49:53She was, uh...a really good research bear.
0:49:53 > 0:49:55Never hurt anybody.
0:49:55 > 0:49:57Was just a gentle, gentle bear.
0:50:07 > 0:50:09It's legal for a landowner to shoot a bear
0:50:09 > 0:50:12if they feel that they or their property is under threat.
0:50:13 > 0:50:16However, they must report the shooting within 48 hours.
0:50:18 > 0:50:20No-one has come forward.
0:50:20 > 0:50:22This shooting is illegal.
0:50:37 > 0:50:40When black bears come into contact with people,
0:50:40 > 0:50:42conflict is all but inevitable.
0:50:48 > 0:50:52Lynn hopes his work will help people understand black bears better,
0:50:52 > 0:50:54so that needless deaths can be avoided.
0:51:09 > 0:51:11As spring gives way to summer,
0:51:11 > 0:51:13Sam, Sophie, and Sybil continue to thrive.
0:51:24 > 0:51:26But when temperatures top 30 degrees,
0:51:26 > 0:51:30tearing around and play fighting aren't quite so much fun.
0:51:33 > 0:51:36The only game in town is staying cool.
0:51:36 > 0:51:40Juliet works hard to get rid of her winter coat.
0:51:44 > 0:51:48When it gets really hot, a dip is irresistible.
0:51:56 > 0:51:59But the heat is more than a nuisance.
0:51:59 > 0:52:04Beneath the greenery, the hot spring has left the undergrowth tinder-dry.
0:52:04 > 0:52:05The bears are now at risk.
0:52:05 > 0:52:07From fire.
0:52:10 > 0:52:13SIRENS WAIL
0:52:13 > 0:52:15This is Highway 1.
0:52:15 > 0:52:17Ely's over that's way in the west and you can see
0:52:17 > 0:52:19the skyline behind me is full of smoke
0:52:19 > 0:52:22and the skies are full of helicopters and aeroplanes.
0:52:22 > 0:52:23A lot of police activity.
0:52:23 > 0:52:25The locals are out trying to see what's going on.
0:52:25 > 0:52:27What I don't know at this stage
0:52:27 > 0:52:29is whether or not the fire's under control.
0:52:33 > 0:52:36I can't believe it, here's a fire right at the edge of town.
0:52:36 > 0:52:38There's a bad wind today that's carrying it into town.
0:52:38 > 0:52:41They're talking about evacuating some of these houses.
0:52:41 > 0:52:43I've never seen anything like this before.
0:52:43 > 0:52:46There's a fire just south of Juliet's territory
0:52:46 > 0:52:50and with this south wind, that means it's going to be blowing it
0:52:50 > 0:52:52into her territory.
0:52:52 > 0:52:57And, uh...she does have three cubs and they climb trees.
0:52:57 > 0:52:59Fire fighters out west have told me
0:52:59 > 0:53:02of hearing the shrieks of cubs as the tree burns up.
0:53:07 > 0:53:11But the biggest worry is Juliet's inexperienced neighbour, Jewel.
0:53:16 > 0:53:19The scent of smoke is everywhere.
0:53:19 > 0:53:22Terrified, Jewel has done exactly what Lynn fears most.
0:53:24 > 0:53:28She's taken little Herbie and Fern up a tree for protection.
0:53:31 > 0:53:35As the cubs scamper around, unaware of the danger,
0:53:35 > 0:53:37Jewel nervously sniffs the air.
0:53:44 > 0:53:46If the fire comes this way,
0:53:46 > 0:53:50the decision to climb a tree could be her last.
0:53:50 > 0:53:52And spell the end for all of them.
0:53:57 > 0:53:59The fire spreads rapidly.
0:54:01 > 0:54:06The emergency services must work tirelessly to contain the blaze.
0:54:10 > 0:54:15Each water plane and helicopter scoops up 7,500 litres of water
0:54:15 > 0:54:20and dumps it ahead of the fire to slow its spread.
0:54:24 > 0:54:26Whoa!
0:54:40 > 0:54:44After 48 exhausting hours, the fire services manage to contain the fire.
0:54:46 > 0:54:48It's devastated a massive swathe of forest.
0:54:52 > 0:54:55But Herbie and Fern are in luck.
0:54:58 > 0:55:02The fire didn't spread to Jewel's territory.
0:55:02 > 0:55:05All three are in one piece.
0:55:05 > 0:55:09For the cubs, it's as if nothing has happened.
0:55:09 > 0:55:12For Jewel, it's another valuable lesson in motherhood.
0:55:25 > 0:55:28Just a few miles away, Juliet was unfazed by the fire.
0:55:30 > 0:55:32With such an experienced mum,
0:55:32 > 0:55:36Sam, Sophie, and Sybil have had a good start in life.
0:55:36 > 0:55:39For them, the summer beckons.
0:55:40 > 0:55:42And with May nearly over,
0:55:42 > 0:55:44it's almost time for me to leave the woods,
0:55:44 > 0:55:46but not before one last visit
0:55:46 > 0:55:51to Juliet, Sam, Sophie, and Sybil.
0:55:51 > 0:55:54So here we are wondering where the cubs might be.
0:55:54 > 0:55:56Silly me! Right at the top of that tree.
0:55:56 > 0:55:58Look at those little bundles!
0:55:58 > 0:56:00They're safe.
0:56:04 > 0:56:05Look at this!
0:56:05 > 0:56:07Sam, Sybil, Sophie, hello! Aw!
0:56:07 > 0:56:09I mean, when they come down that readily,
0:56:09 > 0:56:12when the mother returns to the base of the tree,
0:56:12 > 0:56:14it could mean nursing time.
0:56:14 > 0:56:17And she's sat down and starting to lean back.
0:56:17 > 0:56:20OK. There we go. Look at that, look at that!
0:56:20 > 0:56:23Lynn knew exactly when that was coming.
0:56:23 > 0:56:26- CUBS CHATTER - Ah, there's that noise!
0:56:28 > 0:56:30And they've all got their nipple order sorted out.
0:56:30 > 0:56:33Yeah, see how they're not fighting?
0:56:33 > 0:56:41Sam, who was the most agile early on, has got the hind set.
0:56:41 > 0:56:42I'm surprised to see that.
0:56:42 > 0:56:45The two females have got the best ones.
0:56:45 > 0:56:47I can't understand it,
0:56:47 > 0:56:49but that's why we do research!
0:56:52 > 0:56:55Look at this little one, right by us. Right by us.
0:56:55 > 0:56:58Hello! Hello, Sybil.
0:56:58 > 0:57:01Peek-a-boo! They're playing with us.
0:57:01 > 0:57:03Oh, look! Look at Sam taking a ride!
0:57:03 > 0:57:04Ooh! She doesn't like it!
0:57:04 > 0:57:07SHE LAUGHS
0:57:07 > 0:57:10We've been so incredibly lucky with this family of bears.
0:57:10 > 0:57:14We've seen some very, very special moments between them but this...
0:57:15 > 0:57:16..this is incredible.
0:57:27 > 0:57:29Since we finished filming,
0:57:29 > 0:57:33Sam, Sophie, and Sybil have continued to thrive.
0:57:33 > 0:57:35Sam is still a cheeky chap.
0:57:35 > 0:57:38Adventurous, but also a bit of a mummy's boy.
0:57:38 > 0:57:40He and Sophie are still close,
0:57:40 > 0:57:43the best of buddies through and through.
0:57:47 > 0:57:49Sybil is still left out,
0:57:49 > 0:57:52but seems content, happy to play on her own.
0:57:52 > 0:57:56This independence may well leave her in the best position,
0:57:56 > 0:57:58come family break up next year.
0:58:02 > 0:58:05Juliet has seen them through the toughest period
0:58:05 > 0:58:07they're ever likely to face,
0:58:07 > 0:58:11and all three have had the best possible start
0:58:11 > 0:58:13to their life in the Northwoods.
0:58:46 > 0:58:50Subtitles by Red Bee Media Ltd