0:00:08 > 0:00:13Stretching out before me is the magnificent Yellowstone.
0:00:18 > 0:00:20This is one of the most dynamic...
0:00:22 > 0:00:26..unpredictable and exciting environments on Earth.
0:00:32 > 0:00:33Deep in the Rocky Mountains,
0:00:33 > 0:00:37this vast wilderness is home to North America's
0:00:37 > 0:00:38most iconic wildlife.
0:00:44 > 0:00:47But every year, Yellowstone's animals are pushed
0:00:47 > 0:00:48to their absolute limits.
0:00:50 > 0:00:53Temperatures can swing from -40 in winter
0:00:53 > 0:00:56to approaching plus 40 in summer.
0:00:56 > 0:01:00And at the heart of this change is the thaw.
0:01:01 > 0:01:03The melt can last from March to July...
0:01:05 > 0:01:10..and it's one of the most dramatic, natural events on Earth.
0:01:10 > 0:01:14How do the animals cope with such extremes of temperature?
0:01:16 > 0:01:18We're here to find out.
0:01:21 > 0:01:23I'm joined by biologist Patrick Aryee...
0:01:24 > 0:01:26That's intense.
0:01:27 > 0:01:30..and a team of wildlife cameramen and expert scientists.
0:01:35 > 0:01:39Previously, we've witnessed how animals survive
0:01:39 > 0:01:40Yellowstone's extremes.
0:01:43 > 0:01:46Starting in winter, it was well below freezing
0:01:46 > 0:01:49and some animals really struggled.
0:01:52 > 0:01:58Then, in spring, temperatures jumped nearly 30 degrees in a fortnight
0:01:58 > 0:02:02and wildlife had to cope with the thaw coming three weeks early.
0:02:03 > 0:02:07Now, summer is here and there are new challenges.
0:02:08 > 0:02:12The meltwater will dry up fast,
0:02:12 > 0:02:13food becomes scarce...
0:02:15 > 0:02:17..and if there's no rain,
0:02:17 > 0:02:21wildfires will threaten to destroy the habitats animals rely on.
0:02:23 > 0:02:25SQUEAKING
0:02:26 > 0:02:28Welcome to Yellowstone's Blazing Summer.
0:02:46 > 0:02:49So far in 2016,
0:02:49 > 0:02:53every month has been hotter than average in Greater Yellowstone.
0:02:55 > 0:02:57If the trend continues,
0:02:57 > 0:03:00summer could reach record temperatures
0:03:00 > 0:03:03and push animals to the brink of survival.
0:03:08 > 0:03:10Yellowstone lies over 600 miles
0:03:10 > 0:03:14from the Pacific and has a continental climate,
0:03:14 > 0:03:17which means summers can be relentlessly hot.
0:03:21 > 0:03:25Now, at the moment it's all still looking quite lush and green,
0:03:25 > 0:03:29but in the coming weeks as the temperatures continue to rise,
0:03:29 > 0:03:31the vegetation will start to wither,
0:03:31 > 0:03:34valleys will become dust bowls and lakes and streams
0:03:34 > 0:03:35will start to dry up.
0:03:40 > 0:03:43Wildlife must travel further in search of food,
0:03:43 > 0:03:46drinking water and shelter from the heat.
0:03:48 > 0:03:53Young animals born back in spring are now entering their first summer.
0:03:53 > 0:03:56They're a lot more mobile, but still need to avoid danger
0:03:56 > 0:03:59whilst exploring on those unsteady legs.
0:04:04 > 0:04:07For this latest generation,
0:04:07 > 0:04:10the change in climate will make their lives even more challenging.
0:04:15 > 0:04:18In spring, the beaver family was affected by the
0:04:18 > 0:04:20unusually warm temperatures.
0:04:23 > 0:04:26Huge volumes of meltwater flooded into the Snake River,
0:04:26 > 0:04:29where the beavers have made their home in the south
0:04:29 > 0:04:30of Greater Yellowstone.
0:04:32 > 0:04:35Snow melting from all the way up there in the Teton Mountains
0:04:35 > 0:04:38rushed down in a deluge and threatened to wash
0:04:38 > 0:04:40our beaver dam away.
0:04:42 > 0:04:45Beavers dam rivers to create a series of ponds,
0:04:45 > 0:04:48where they live and feed, safe from predators.
0:04:49 > 0:04:53After working flat out on emergency repairs to the dam,
0:04:53 > 0:04:56the beavers just managed to save their home from the flood.
0:05:00 > 0:05:04Now, in summer, the family could face the opposite challenge -
0:05:04 > 0:05:06too little water in the river.
0:05:08 > 0:05:11I've come to meet wildlife cameraman Jeff Hogan
0:05:11 > 0:05:13who's been following the beavers.
0:05:15 > 0:05:16Hey, Jeff.
0:05:17 > 0:05:20- How's it going?- There you are. How are you doing?
0:05:20 > 0:05:23Jeff was filming great grey owls in spring.
0:05:23 > 0:05:28Now, he'll use his specialist skills to study the beavers and has
0:05:28 > 0:05:32installed an infrared camera inside their lodge.
0:05:34 > 0:05:36SQUEAKING
0:05:38 > 0:05:39I've got something to show you.
0:05:39 > 0:05:41It was a bit of a surprise.
0:05:43 > 0:05:49'This footage looks like the male and female I saw here in spring.'
0:05:49 > 0:05:52- You see a couple of big, fat beavers?- Yeah.
0:05:52 > 0:05:54SQUEAKING
0:05:56 > 0:05:59'But then, something unexpected.'
0:06:06 > 0:06:08Oh, my gosh!
0:06:08 > 0:06:10PATRICK LAUGHS
0:06:10 > 0:06:13- They're so adorable. - That's a great shot.
0:06:15 > 0:06:17- Oh, my goodness.- That's amazing.
0:06:17 > 0:06:18No way.
0:06:20 > 0:06:23Oh man, they're so adorable.
0:06:29 > 0:06:33'Baby beavers are called kits and Mum has given birth to three.'
0:06:35 > 0:06:38I would say they're probably about ten weeks of age, maybe.
0:06:41 > 0:06:43'Kits are precocial,
0:06:43 > 0:06:47'which means they're mobile and quite advanced from birth.
0:06:47 > 0:06:51'Emerging with a full coat of thick fur, sharp chisel-like teeth...
0:06:54 > 0:06:56'..and a characteristic flat tail.
0:06:59 > 0:07:02'This, they use as a rudder to steer when swimming,
0:07:02 > 0:07:05'which they can do within a day of being born.
0:07:07 > 0:07:10'But these three still rely on their family to bring them food
0:07:10 > 0:07:12'from outside the lodge.'
0:07:14 > 0:07:16I've got another clip for you.
0:07:19 > 0:07:21SQUEAKING
0:07:21 > 0:07:24Look at all that willow.
0:07:24 > 0:07:27This adult beaver just brought in three or four branches,
0:07:27 > 0:07:28all bundled up.
0:07:32 > 0:07:35And the little young ones will just jump on this.
0:07:37 > 0:07:39They'll gobble that right down.
0:07:48 > 0:07:51'At ten weeks old, these kits have stopped drinking
0:07:51 > 0:07:52'their mother's milk.
0:07:52 > 0:07:54'They now have an adult diet.'
0:08:00 > 0:08:02In summer, the ponds the beavers create
0:08:02 > 0:08:05become their vegetable gardens.
0:08:05 > 0:08:09The slow, warm waters create optimal conditions
0:08:09 > 0:08:10for edible plants to grow.
0:08:17 > 0:08:22Mum, Dad and last year's young are working overtime collecting food
0:08:22 > 0:08:26for the kits and keeping the lodge clean by washing grassy bedding.
0:08:41 > 0:08:42In a matter of days,
0:08:42 > 0:08:46the kits will leave the lodge and learn to forage for their own food,
0:08:46 > 0:08:48whilst avoiding predators.
0:08:50 > 0:08:55Around 50% of beaver kits don't survive their first six months.
0:08:55 > 0:08:58It's a critical time for this family, and Jeff
0:08:58 > 0:09:01will be following them every step of the way.
0:09:06 > 0:09:10Across Yellowstone, our teams have been documenting signs
0:09:10 > 0:09:14that an early spring thaw kick-started an early summer.
0:09:16 > 0:09:21As icy meltwaters flowing off the mountains subsided,
0:09:21 > 0:09:23streams warmed rapidly in the sun.
0:09:25 > 0:09:29And the surface of the water started to dance.
0:09:36 > 0:09:41Rising water temperatures trigger mayflies to hatch in their millions.
0:09:55 > 0:09:59These conditions are the starting pistol for an important event...
0:10:03 > 0:10:06The arrival of cutthroat trout.
0:10:09 > 0:10:13Many have spent the winter in Yellowstone's deep rivers and lakes,
0:10:13 > 0:10:17but migrate upstream to feed on mayflies and spawn
0:10:17 > 0:10:19in these shallow waters.
0:10:23 > 0:10:28Every year, the arrival of these protein-rich fish creates a
0:10:28 > 0:10:31feeding bonanza for river otters, mink,
0:10:31 > 0:10:36bears and birds of prey, like eagles and osprey.
0:10:37 > 0:10:41Over 20 different species of birds and mammals.
0:10:45 > 0:10:49This year, the early snowmelt has given these predators a head start
0:10:49 > 0:10:50to fatten up.
0:10:56 > 0:10:59While summer temperatures have created a frenzy of activity
0:10:59 > 0:11:03on the rivers, Yellowstone's low altitude grasslands
0:11:03 > 0:11:05are eerily quiet.
0:11:07 > 0:11:10'In spring, herds of elk and bison were feeding here,
0:11:10 > 0:11:15'but they've moved on as the green vegetation withers in the heat.
0:11:16 > 0:11:19'What the locals call "the brown-up" has begun.'
0:11:22 > 0:11:26Over the course of just a few months, this ground has gone
0:11:26 > 0:11:28from being covered in feet of snow to lush grass,
0:11:28 > 0:11:33which has now scorched, died away and has very little nutrition.
0:11:33 > 0:11:37So grazing animals like bison and elk need to move further up
0:11:37 > 0:11:39the mountains in search of green shoots.
0:11:42 > 0:11:45As the summer continues, the brown-up will creep higher.
0:11:48 > 0:11:51Bison and elk must keep moving.
0:11:57 > 0:12:00By July, bison have arrived at summer grazing grounds
0:12:00 > 0:12:03on Yellowstone's high plateau.
0:12:06 > 0:12:11This is the only time mature males and females come together
0:12:11 > 0:12:14and herds can reach a thousand strong.
0:12:15 > 0:12:18Scientists think this summer the bison will look
0:12:18 > 0:12:21particularly impressive after an abundance of grazing
0:12:21 > 0:12:23during a warm spring.
0:12:23 > 0:12:26So Kate's gone to check out what kind of condition they're in.
0:12:30 > 0:12:32Oh, my goodness!
0:12:32 > 0:12:34What a magnificent beast.
0:12:36 > 0:12:43The male bison at this time of year are truly just...
0:12:43 > 0:12:45They are in their prime.
0:12:48 > 0:12:54'Bulls have piled on up to 150kg of fat and muscle
0:12:54 > 0:12:57'and now is their chance to start throwing that weight around.
0:13:00 > 0:13:05'July is rutting season, when males duel for the right to mate.
0:13:05 > 0:13:09'And this year's favourable conditions mean it will be fierce.
0:13:11 > 0:13:13'The largest contenders could be tipping the scales
0:13:13 > 0:13:15'at nearly a tonne.'
0:13:18 > 0:13:21You may think, "Isn't it a little bit early for sex?
0:13:21 > 0:13:23"I mean, you know, it's the summer, they should be chilling out."
0:13:23 > 0:13:27But remember that bison are the first to give birth.
0:13:28 > 0:13:31Think back to the spring, the first calves we saw,
0:13:31 > 0:13:32they were bison calves.
0:13:35 > 0:13:39'Female bison have one of the longest pregnancies here,
0:13:39 > 0:13:41'lasting over nine months.
0:13:43 > 0:13:47'So to time the birth of calves with the start of next spring...
0:13:49 > 0:13:51'..these males need to get on with it.'
0:14:01 > 0:14:05This male bison has found himself the perfect dust bath.
0:14:09 > 0:14:13And, at various times throughout the day, he will roll in it,
0:14:13 > 0:14:15he'll cover himself in dust, he'll pee in the dust
0:14:15 > 0:14:17and roll in that.
0:14:21 > 0:14:26Just to make sure that he smells as virile and ready for it as possible.
0:14:27 > 0:14:31LOW GRUMBLE
0:14:33 > 0:14:37'Wallowing in dust baths is a show of strength.
0:14:43 > 0:14:47'Each male competes to churn up the biggest dust cloud
0:14:47 > 0:14:49'and intimidate its rivals.
0:14:53 > 0:14:58'But when two heavyweights won't back down, they go head-to-head.
0:15:03 > 0:15:07Heavily-muscled necks and thick skulls covered in a mat of
0:15:07 > 0:15:12dense hair help absorb the colossal forces of each collision.
0:15:16 > 0:15:20Only the winner earns the right to mate.
0:15:28 > 0:15:33This ensures the strongest genes will be passed on.
0:15:37 > 0:15:41Whilst I've been following herds of prey animals on the plateau...
0:15:43 > 0:15:46..our camera crews are at lower altitudes on the trail of
0:15:46 > 0:15:50Yellowstone's top predator, the wolf.
0:15:53 > 0:15:58Over 500 wolves roam across Greater Yellowstone.
0:15:58 > 0:16:02The mild winter and spring caused many packs to go hungry
0:16:02 > 0:16:06as the prey was well fed and could outrun the wolves.
0:16:08 > 0:16:13In summer, the stakes are even higher because there are young pups
0:16:13 > 0:16:14to feed.
0:16:17 > 0:16:19In the south of Greater Yellowstone,
0:16:19 > 0:16:24biologists have been studying one wolf pack that seems to be defying
0:16:24 > 0:16:26the odds and thriving this year -
0:16:26 > 0:16:28the Pinnacle Peak pack.
0:16:30 > 0:16:33This photo was taken during an aerial survey.
0:16:33 > 0:16:36It reveals the pack has 11 pups.
0:16:36 > 0:16:41Unusually, two females have given birth this year -
0:16:41 > 0:16:43a sign this pack is doing well.
0:16:45 > 0:16:49All the adults take it in turns to hunt and return to the den sites
0:16:49 > 0:16:51with meat for the pups.
0:16:51 > 0:16:55But the elk that make up the majority of wolves' prey have moved
0:16:55 > 0:16:57to higher grazing grounds.
0:17:01 > 0:17:05The biologists have been observing how the pack finds enough food
0:17:05 > 0:17:09for all 11 pups. They've directed wildlife cameraman
0:17:09 > 0:17:13Charlie Hamilton James to an area where they've seen
0:17:13 > 0:17:14remarkable behaviour.
0:17:16 > 0:17:20They think the key to the wolves' success here could be down
0:17:20 > 0:17:21to human activity.
0:17:36 > 0:17:37See it?
0:17:45 > 0:17:46I wonder if
0:17:46 > 0:17:48she's going to let me get out.
0:17:49 > 0:17:50I'm going to give it a go.
0:17:52 > 0:17:53Bear with me on this.
0:18:17 > 0:18:20- WHISPERS:- Well, well, well, well, well!
0:18:30 > 0:18:32How beautiful is that?
0:18:32 > 0:18:36She can smell me. My scent is going straight ahead.
0:18:36 > 0:18:37She knows I'm here.
0:18:38 > 0:18:40She's not bothered at all.
0:18:43 > 0:18:45In all his 20 years of filming,
0:18:45 > 0:18:49Charlie has never been this close to a wild wolf.
0:18:53 > 0:18:56This female is from the Pinnacle Peak pack.
0:19:00 > 0:19:01And something has drawn her here.
0:19:06 > 0:19:08The grass is still green
0:19:08 > 0:19:12because it's been watered over the summer to improve grazing.
0:19:21 > 0:19:22You can see all these sprinklers behind her.
0:19:22 > 0:19:25Cos they're watering the grass,
0:19:25 > 0:19:27it's created some amazing habitat for ground squirrels.
0:19:27 > 0:19:29There's just tonnes of them.
0:19:36 > 0:19:38A huge colony of grass-eating
0:19:38 > 0:19:42Uinta ground squirrels is exploiting this artificial oasis.
0:19:45 > 0:19:49Usually, by mid-July, the grass would be turning brown and inedible.
0:19:50 > 0:19:54The squirrels would have started entering their burrows to hibernate,
0:19:54 > 0:19:55but not here.
0:19:58 > 0:20:02This female wolf has spotted the chance of an easy meal.
0:20:05 > 0:20:09And it's closer to the pups than the large elk herds 20 miles away.
0:20:19 > 0:20:22They need these ground squirrels cos they're tied to their territory.
0:20:22 > 0:20:24They've got pups here, they can't go anywhere else,
0:20:24 > 0:20:26so they have to find food around here...
0:20:27 > 0:20:29..just to survive and keep those pups alive.
0:20:32 > 0:20:36But catching these burrowing rodents is tricky.
0:20:39 > 0:20:43They spend much of their time looking for danger,
0:20:43 > 0:20:47balancing on their hind legs to see over the tall grass.
0:20:53 > 0:20:58The squirrels also have a range of alarm calls for different threats.
0:21:04 > 0:21:06SQUIRREL TRILLS
0:21:07 > 0:21:11A trill means it's a ground-based predator.
0:21:11 > 0:21:13SQUIRREL TRILLS
0:21:15 > 0:21:19The entire colony dive for the safety of their burrows.
0:21:25 > 0:21:28Look at that! She's on it. She's on one. She's on one. Oh!
0:21:33 > 0:21:37This female is putting in a lot of work but without any reward.
0:21:41 > 0:21:44Oh, there's another one. There we go! There's one running.
0:21:44 > 0:21:45Ah! Where is it? Where is it? Where is it?
0:21:45 > 0:21:46A long way off.
0:21:54 > 0:21:58Another pack member may help turn the tables.
0:21:58 > 0:22:01Wolves' real strength is when they hunt together.
0:22:15 > 0:22:16There's another one.
0:22:19 > 0:22:21There's another wolf!
0:22:33 > 0:22:35I don't know which one to film now.
0:22:36 > 0:22:39SQUIRRELS TRILL
0:22:40 > 0:22:43The ground squirrels can't watch all three wolves at once.
0:22:48 > 0:22:53And these newcomers are also trying a different hunting strategy
0:22:53 > 0:22:55to outwit their quarry.
0:22:56 > 0:22:57SQUIRREL SQUEAKS
0:23:03 > 0:23:07There's a lot of activity and then they'll lie down.
0:23:07 > 0:23:10And you think, well, why are they suddenly lying down?
0:23:14 > 0:23:17Part of their hunting strategy is to lie down
0:23:17 > 0:23:21and essentially just wait for the ground squirrels to come up to them,
0:23:21 > 0:23:23you know, and they're sort of dozing and they're half asleep, and
0:23:23 > 0:23:25a ground squirrel comes up and they just leap up and grab it.
0:23:35 > 0:23:36It's working.
0:23:39 > 0:23:42Even the original female is having more luck.
0:23:53 > 0:23:58With animals, you get these peak moments of activity and they last
0:23:58 > 0:24:01for a few days or a few weeks and then they're gone again.
0:24:02 > 0:24:07It's incredibly lucky that we've been able to be here for this
0:24:07 > 0:24:09particular period of peak activity.
0:24:09 > 0:24:12I've never seen it before, I don't know if it'll ever happen again,
0:24:12 > 0:24:14but it's amazing to witness it.
0:24:21 > 0:24:26These wolves have used all their intelligence to exploit this situation.
0:24:35 > 0:24:39The food will increase the pups' chance of survival.
0:24:51 > 0:24:55And more wolves means a stronger pack next year.
0:25:08 > 0:25:11It's early July and no rain has fallen this month
0:25:11 > 0:25:14at the Snake River, where the beavers have their home.
0:25:16 > 0:25:19This, combined with the early snow melt,
0:25:19 > 0:25:22means that the river is running 20% below its average.
0:25:25 > 0:25:29If the level of the beavers' main pond drops too low, it could expose
0:25:29 > 0:25:32the entrance to their lodge, which is usually underwater.
0:25:32 > 0:25:35And this would make them easy pickings for predators.
0:25:40 > 0:25:43Jeff is watching them closely to see how they react.
0:25:45 > 0:25:48Oh, look! Wow!
0:25:48 > 0:25:49That's Mum.
0:25:50 > 0:25:54And it looks like Mum has made an executive decision.
0:25:54 > 0:25:57She's got one of the kits in her mouth.
0:25:57 > 0:25:59She's heading towards the dam.
0:25:59 > 0:26:01She's moving one of her kits out of the pond,
0:26:01 > 0:26:03maybe to search for a new home.
0:26:10 > 0:26:11This is incredible!
0:26:17 > 0:26:18And there they go.
0:26:18 > 0:26:20I'm going to go chase them.
0:26:23 > 0:26:26Scientists have observed beaver families relocating,
0:26:26 > 0:26:31but Jeff has never witnessed it in 20 years of studying them.
0:26:31 > 0:26:36Out in the open, kits are vulnerable to predators like bald eagles.
0:26:36 > 0:26:38It's a tense moment for Mum and her young.
0:26:46 > 0:26:47Here they come.
0:26:49 > 0:26:51The beaver family's territory is large,
0:26:51 > 0:26:55with five dams and pools along this river.
0:26:55 > 0:26:57She's going to crawl over this next dam.
0:27:14 > 0:27:17After travelling more than 350 metres...
0:27:19 > 0:27:20..and crossing three more dams...
0:27:22 > 0:27:27..Jeff films the mum leading her kit up a small channel that comes off
0:27:27 > 0:27:29the main river.
0:27:29 > 0:27:33They're going to climb right up through this cascading stream...
0:27:34 > 0:27:35..waddling up through the stones.
0:27:35 > 0:27:38You can see that the beavers don't do quite so well on land,
0:27:38 > 0:27:41especially with this river rock.
0:27:41 > 0:27:43They do so much better in the water.
0:27:45 > 0:27:47Unreal!
0:27:47 > 0:27:49Never seen this, ever!
0:27:51 > 0:27:52And there they go.
0:27:55 > 0:28:00Later, at night, Jeff checks his camera in the lodge.
0:28:00 > 0:28:01Let's see.
0:28:08 > 0:28:13It reveals Mum has moved all the kits and the whole family has
0:28:13 > 0:28:14abandoned their home.
0:28:19 > 0:28:23Jeff is now on a mission to find out where the beavers have gone...
0:28:24 > 0:28:28..if the kits survive and whether this huge gamble will pay off.
0:28:33 > 0:28:37Whilst the low-lying rivers and grasslands are sweltering
0:28:37 > 0:28:39in temperatures of nearly 30 degrees...
0:28:40 > 0:28:45..2,000 metres up, Yellowstone peaks have a recent dusting of fresh snow.
0:28:48 > 0:28:51And the mountain meadows are a riot of colour.
0:29:03 > 0:29:08It is amazing, the contrast up here to down in the valley.
0:29:08 > 0:29:11Down in the valley, summer has really taken grip -
0:29:11 > 0:29:15the temperatures are quite high and the grass is starting to go brown.
0:29:15 > 0:29:20But up here, 800 metres higher, it's a totally different story.
0:29:20 > 0:29:25It's breezy, it's cool, and look at all these magnificent wild flowers!
0:29:37 > 0:29:41Susan Marsh is a naturalist and she pays very close attention to these
0:29:41 > 0:29:44high-altitude wild flowers.
0:29:46 > 0:29:48Where most people see pretty petals,
0:29:48 > 0:29:54Susan sees a living record of how this ecosystem is being affected
0:29:54 > 0:29:57by this year's weather and the changing climate.
0:30:00 > 0:30:04We've looked a lot at how animals can indicate
0:30:04 > 0:30:06the state of how a year is progressing,
0:30:06 > 0:30:08as far as the weather is concerned.
0:30:08 > 0:30:11Are the plants just as valuable as indicators?
0:30:11 > 0:30:12Yes. I think they are
0:30:12 > 0:30:14and the one advantage
0:30:14 > 0:30:15that they have, in my opinion,
0:30:15 > 0:30:17is that they don't run off!
0:30:17 > 0:30:18And they don't fly away.
0:30:18 > 0:30:22- Very true.- I can tell by how tall they are, first of all.
0:30:22 > 0:30:25- Right.- This one is fireweed.
0:30:25 > 0:30:30And it, typically, in a really lush year, will grow head high.
0:30:30 > 0:30:32- Wow!- Even at this elevation.
0:30:32 > 0:30:36These particular ones, you can see, are only a couple of feet tall.
0:30:36 > 0:30:41- Yeah, yeah.- To me that's an indication of heat and dryness.
0:30:41 > 0:30:45The plant needs to set seed and it has a very short growing season,
0:30:45 > 0:30:49so it's not going to waste its energy making a big, tall stalk,
0:30:49 > 0:30:51or making great big leaves.
0:30:51 > 0:30:54- Right.- These leaves are small this year, smaller than usual.
0:30:57 > 0:31:02Through these plants, Susan can chart this year's erratic weather
0:31:02 > 0:31:06but can plants also indicate larger changes?
0:31:07 > 0:31:11Everyone is talking about the fact that the climate is changing.
0:31:11 > 0:31:15Is that something that is becoming evident in the plants?
0:31:15 > 0:31:17It's typically on the mountain tops.
0:31:17 > 0:31:18So that's above the tree line.
0:31:18 > 0:31:24Above the trees, where there's rocks and wind and cold.
0:31:28 > 0:31:33It's the coldest part of Yellowstone, above 3,000 metres,
0:31:33 > 0:31:37where Susan is seeing the effects of climate change hit hard.
0:31:41 > 0:31:46This is the alpine zone, a realm of high-altitude specialists.
0:31:48 > 0:31:51But as temperatures keep getting warmer,
0:31:51 > 0:31:56non-specialist plants are able to survive higher up the mountains
0:31:56 > 0:31:59and they're invading this fragile zone.
0:32:02 > 0:32:05Does it concern you that you are seeing
0:32:05 > 0:32:08a march towards a very different climate
0:32:08 > 0:32:12and, therefore, a very different ecosystem?
0:32:12 > 0:32:14I think there will be some good and some bad,
0:32:14 > 0:32:17depending on what species you are, as climate change continues.
0:32:17 > 0:32:21But, yes, I don't want to lose the wildflower parts that I love.
0:32:21 > 0:32:23I don't want to lose the alpine zone.
0:32:25 > 0:32:26I don't want to see those go,
0:32:26 > 0:32:29but I don't think I can stop it.
0:32:34 > 0:32:37Climatologists studying Greater Yellowstone
0:32:37 > 0:32:39have charted temperatures increasing
0:32:39 > 0:32:42by nearly a fifth of a degree every decade.
0:32:43 > 0:32:48This seemingly small change is having far-reaching consequences.
0:32:49 > 0:32:50Across Yellowstone,
0:32:50 > 0:32:54scientists are seeing how animals are being forced to adapt.
0:32:58 > 0:33:03Even the most iconic species like the grizzly bear are being affected.
0:33:05 > 0:33:07To find out what's going on,
0:33:07 > 0:33:10Patrick has gone to the Gallatin mountain range
0:33:10 > 0:33:12in the north-west of Greater Yellowstone.
0:33:16 > 0:33:19I've come to meet our bear expert, Casey Anderson,
0:33:19 > 0:33:23to see how one group of grizzly bears is coping,
0:33:23 > 0:33:26as the changing climate threatens an important food source.
0:33:29 > 0:33:31If you look up at this knob up here,
0:33:31 > 0:33:34take a look at the trees just around the bottom of that.
0:33:34 > 0:33:35Those are white bark pines.
0:33:35 > 0:33:36Let's have a look.
0:33:40 > 0:33:43That entire forest of white bark pine, ancient trees,
0:33:43 > 0:33:45some of them are 300 years old,
0:33:45 > 0:33:48they've all died in the last couple of years.
0:33:48 > 0:33:49They're gone.
0:33:51 > 0:33:54What's caused it to die off?
0:33:54 > 0:33:56There's a pine beetle that's always existed up there,
0:33:56 > 0:33:59but we've had these cold winters
0:33:59 > 0:34:01that usually just killed most of the beetles,
0:34:01 > 0:34:04but now, with climate change, those winters are not as harsh,
0:34:04 > 0:34:07we're not having that beetle kill
0:34:07 > 0:34:09that we're used to in the middle of the winter,
0:34:09 > 0:34:12so the beetles are really starting to infest the forest.
0:34:13 > 0:34:17Pine beetles are no bigger than grains of rice
0:34:17 > 0:34:21but these small creatures cause big problems.
0:34:21 > 0:34:24Not only do their young eat the trees' living tissue,
0:34:24 > 0:34:27but they also introduce a destructive fungus.
0:34:27 > 0:34:32Eventually, this combination kills the entire tree.
0:34:32 > 0:34:34This is bad news for the animals
0:34:34 > 0:34:38that rely upon the food and shelter this tree provides.
0:34:42 > 0:34:45Towards the end of summer, as other food sources dry up,
0:34:45 > 0:34:49these pine nuts usually provide vital protein for grizzlies.
0:34:56 > 0:35:00One aerial survey revealed around 80% of mature white barked trees in
0:35:00 > 0:35:03Greater Yellowstone show signs
0:35:03 > 0:35:06of moderate-to-severe beetle infestation.
0:35:06 > 0:35:09To survive, the bears must adapt
0:35:10 > 0:35:14and Casey has witnessed some intriguing behaviour.
0:35:16 > 0:35:19Grizzlies are leaving the wilderness
0:35:19 > 0:35:21to congregate on this cattle ranch to feed.
0:35:27 > 0:35:29What they are eating is this caraway root
0:35:29 > 0:35:31that actually came in with livestock.
0:35:31 > 0:35:34It's actually an introduced species not native to the area
0:35:34 > 0:35:36and they're coming down here and taking advantage of it.
0:35:38 > 0:35:41And all the bears in the area are starting to migrate towards this meadow
0:35:41 > 0:35:44because there's not a lot of food out there in the summer but,
0:35:44 > 0:35:47right here, this is like a bear buffet!
0:35:47 > 0:35:48It's a race against time.
0:35:48 > 0:35:51The bears must pile on enough fat
0:35:51 > 0:35:55to see them through five months of hibernation.
0:35:55 > 0:35:58While the root is at its most abundant in summer and autumn,
0:35:58 > 0:36:01the grizzlies gorge throughout the night,
0:36:01 > 0:36:05eating up to 20,000 calories in a single sitting.
0:36:14 > 0:36:16As the day heats up,
0:36:17 > 0:36:21the hot sun forces them back into the shady forest to rest.
0:36:26 > 0:36:28But Casey and our mobile camera team
0:36:30 > 0:36:34have seen two bears that are still out in the midday sun.
0:36:36 > 0:36:37Hey, Casey, do you copy?
0:36:41 > 0:36:44They're, like, totally tumbling around out there.
0:36:46 > 0:36:50Well, they're little playful guys!
0:37:00 > 0:37:02These two yearlings are orphans.
0:37:02 > 0:37:05Unfortunately, their mum died last autumn but,
0:37:05 > 0:37:09against the odds, they have turned up in this meadow.
0:37:10 > 0:37:12I've joined Casey to see how they're doing.
0:37:13 > 0:37:17Right here, there's two yearling grizzly cubs,
0:37:17 > 0:37:19right out here, digging around.
0:37:19 > 0:37:21Oh, yeah, right there.
0:37:25 > 0:37:27They're still young and inexperienced.
0:37:28 > 0:37:32Cubs usually stay with their mums for up to three and a half years
0:37:32 > 0:37:34but, even with this protection,
0:37:34 > 0:37:37almost a third won't survive in Yellowstone.
0:37:39 > 0:37:41It's a miracle that these two
0:37:41 > 0:37:44made it through an entire winter on their own.
0:37:51 > 0:37:53Do you think that having one another
0:37:53 > 0:37:57is one of the reasons why they've made it this far?
0:37:57 > 0:38:00I think it's got to be one of the biggest reasons.
0:38:02 > 0:38:06If they didn't have each other, I don't think there's any chance
0:38:06 > 0:38:08that one of them would have survived.
0:38:08 > 0:38:10They've got each other's back.
0:38:14 > 0:38:16Whilst feeding on this working ranch,
0:38:16 > 0:38:19there are lots of unusual sights and sounds.
0:38:26 > 0:38:28But without a mum to teach them,
0:38:28 > 0:38:32it's hard for the cubs to know what is and isn't dangerous.
0:38:36 > 0:38:38You find yourself really worrying about them
0:38:40 > 0:38:42because they don't have
0:38:42 > 0:38:44that notorious Mama Grizzly looking out for them.
0:38:53 > 0:38:55Yeah, they're looking a little bit nervous.
0:38:55 > 0:38:58So they're looking at something over in the distance.
0:39:02 > 0:39:05They've obviously sensed something in that direction.
0:39:05 > 0:39:07I think that these two have probably been chased,
0:39:07 > 0:39:11probably once a day, by something, whether it's another grizzly,
0:39:11 > 0:39:13a pack of wolves, or even cattle.
0:39:20 > 0:39:23Surprisingly, the dangers may not come from the ranchers
0:39:23 > 0:39:24or their cattle.
0:39:26 > 0:39:29Most have learned to live alongside their grizzly neighbours.
0:39:31 > 0:39:35One of the biggest threats comes in the form of other bears
0:39:35 > 0:39:38close by in the shade of the forests.
0:39:42 > 0:39:47A big male grizzly, known as a boar, could kill and eat the cubs
0:39:47 > 0:39:51but it looks like these two have found a way to avoid this danger.
0:39:51 > 0:39:54The big boars and other bears are out at night
0:39:54 > 0:39:55because when it's hot, like this,
0:39:55 > 0:39:57most bears will not come out and dig,
0:39:57 > 0:39:59because it just wears them out.
0:40:00 > 0:40:03And as the sun comes up, they go back to the forest.
0:40:03 > 0:40:06With these little guys, they're kind of on the opposite schedule.
0:40:06 > 0:40:09When the danger goes away, it's time to eat.
0:40:11 > 0:40:15Let's do it in the heat of the day when there's nobody else out here.
0:40:15 > 0:40:17Where you don't have to worry about anything.
0:40:17 > 0:40:20That's what they're doing and it's working for them.
0:40:20 > 0:40:22It's an amazing strategy.
0:40:25 > 0:40:27The two cubs are a fantastic indicator
0:40:27 > 0:40:30of just how intelligent bears can be.
0:40:32 > 0:40:35Even as climate change kills off the white bark pine,
0:40:35 > 0:40:39the bears are adapting to exploit the opportunities.
0:40:40 > 0:40:44With over 700 grizzlies in Greater Yellowstone,
0:40:44 > 0:40:48the latest data suggests their population, for now, at least,
0:40:48 > 0:40:49has remained stable.
0:40:58 > 0:41:03Yellowstone hasn't reached its record temperature of 36 degrees
0:41:05 > 0:41:09but climate data has revealed that July, this year,
0:41:09 > 0:41:13was the seventh month in a row with above average temperatures.
0:41:20 > 0:41:23The relentless heat
0:41:23 > 0:41:26and the early thaw are a dangerous combination.
0:41:29 > 0:41:32They may create perfect conditions...
0:41:34 > 0:41:36..for wildfires.
0:41:39 > 0:41:43In normal years, the snowmelt would come down off the mountains,
0:41:43 > 0:41:45and it would hang around places, like this,
0:41:45 > 0:41:48soaking into all this dead wood, but not this year.
0:41:48 > 0:41:51What it did was come rushing off in a great torrent
0:41:51 > 0:41:53into the rivers, into the streams, into the lakes
0:41:53 > 0:41:58and it didn't have time to soak into all of this dead, dry wood.
0:41:58 > 0:42:02So this is, basically, fuel for fires
0:42:02 > 0:42:05and having so much dead, dry wood around
0:42:05 > 0:42:08means that there is a danger this year
0:42:08 > 0:42:10of bigger and more intense fires.
0:42:12 > 0:42:16A single spark could set this landscape alight.
0:42:18 > 0:42:21Every summer, an average of 26 wildfires
0:42:21 > 0:42:24are started by lightning across Yellowstone National Park.
0:42:30 > 0:42:34Our crews are out, following up on reports of wildfire.
0:42:35 > 0:42:41Flames can reach heights of 50 metres, exceed 1,200 Celsius,
0:42:41 > 0:42:45and rip through the landscape at up to 40mph.
0:42:45 > 0:42:48By mid-August, the tinder-dry conditions
0:42:48 > 0:42:51mean five major fires have taken hold,
0:42:51 > 0:42:54and are raging across the region.
0:42:56 > 0:43:01In the Beartooth Mountains is wildlife cameraman Jeff Hogan.
0:43:02 > 0:43:03Oh, no, this is nuts!
0:43:04 > 0:43:08He's filming a wildfire that's consuming a huge area of forest.
0:43:09 > 0:43:12And it's headed straight towards the family of great grey owls
0:43:12 > 0:43:14he's been following since spring.
0:43:24 > 0:43:26This fire is huge, and it's raging.
0:43:26 > 0:43:30It's right in the backyard of our great grey owl family.
0:43:30 > 0:43:31This is really a threat.
0:43:38 > 0:43:41So far, the chicks have done much better than expected.
0:43:44 > 0:43:48There was only a 20% chance all three would make it out of the nest.
0:43:48 > 0:43:51Oh, he's going to go, he's going to go.
0:43:51 > 0:43:53Jump, jump!
0:43:55 > 0:43:56Oh, wow!
0:43:57 > 0:44:00Jeff thought their biggest challenges were over.
0:44:08 > 0:44:11But now, he'll have to wait until the fire's died down
0:44:11 > 0:44:13to see if these young owls survive.
0:44:18 > 0:44:19Oh, my goodness.
0:44:21 > 0:44:24The aftermath of a fire might seem devastating,
0:44:24 > 0:44:27but it's actually part of the forest's natural cycle.
0:44:27 > 0:44:30It brings growth and new life.
0:44:30 > 0:44:34All this ash is actually really fertile
0:44:34 > 0:44:36and as soon as it rains,
0:44:36 > 0:44:39new green shoots are going to start popping up,
0:44:39 > 0:44:42and that's going to encourage grazers like elk and deer
0:44:42 > 0:44:46to come into this area and, eventually, grizzly bears.
0:44:46 > 0:44:50But not only that, some plants have actually evolved
0:44:50 > 0:44:55to benefit from fires. These here are lodgepole pine cones
0:44:55 > 0:44:59and they only open up once they reach a specific temperature
0:44:59 > 0:45:02that can only be produced by a fire
0:45:02 > 0:45:05and then these seeds will eventually fall off,
0:45:05 > 0:45:07down into the ground
0:45:07 > 0:45:09and be fertilised by the ash.
0:45:12 > 0:45:15Fires are a natural part of life here.
0:45:15 > 0:45:18But by the time they die down,
0:45:18 > 0:45:21they will have burnt nearly 100 square miles of land.
0:45:23 > 0:45:26This year's fires will have been the most destructive
0:45:26 > 0:45:30inside Yellowstone National Park since 1988.
0:45:30 > 0:45:33Large-scale fires used to sweep through the park
0:45:33 > 0:45:35around every 300 years.
0:45:35 > 0:45:40But scientists now believe that the warming climate could result
0:45:40 > 0:45:44in them happening every 3-5 years by the end of this century.
0:45:46 > 0:45:49This could result in the destruction of the forest
0:45:49 > 0:45:53that's home to the fragile population of great grey owls.
0:45:57 > 0:46:01Jeff is searching the area at the edge of the burn
0:46:01 > 0:46:03for any sign of the owl family.
0:46:08 > 0:46:11There's a lot of ground to cover
0:46:11 > 0:46:15so Jeff calls in expert animal tracker Dan Hartman.
0:46:16 > 0:46:19After four days' searching,
0:46:19 > 0:46:24Dan finally hears an adult great grey.
0:46:26 > 0:46:28OWL CALLS
0:46:32 > 0:46:35And close by, one of the young owls.
0:46:37 > 0:46:40OWL CALLS CONTINUE
0:46:45 > 0:46:49After another few minutes watching and listening,
0:46:49 > 0:46:51he spots the other two siblings.
0:47:04 > 0:47:06All of them have survived.
0:47:10 > 0:47:14And they're even making their first attempt at hunting.
0:47:22 > 0:47:26The owl chicks have all made it through their first summer,
0:47:26 > 0:47:31but we still don't know the fate of the beaver mum and her three kits.
0:47:35 > 0:47:38I've joined Jeff on a tributary of the Snake River,
0:47:38 > 0:47:43where he's seen signs that the beavers are making a new home.
0:47:44 > 0:47:46He thinks it's a safer location,
0:47:46 > 0:47:50as the water level is higher than at their old pond.
0:48:07 > 0:48:09Oh, look.
0:48:12 > 0:48:14There's your beaver sitting there.
0:48:14 > 0:48:16Oh, my... Is it that beaver there?
0:48:16 > 0:48:18That's the beaver, right there.
0:48:18 > 0:48:21This is just gold dust.
0:48:23 > 0:48:25This looks like Mum.
0:48:25 > 0:48:29And in the few weeks since moving, the family has been busy building.
0:48:34 > 0:48:36That is a new lodge being built right now.
0:48:36 > 0:48:39They just make a big pile of sticks,
0:48:39 > 0:48:42then they go into it and start digging it up
0:48:42 > 0:48:43and they'll pile mud and stuff up on top of it.
0:48:45 > 0:48:49This is a lodge at its early stages.
0:48:49 > 0:48:50This is rare.
0:48:50 > 0:48:55Rarely do you see the very early stages of a whole new beaver pond
0:48:55 > 0:48:57with a lodge like this.
0:49:01 > 0:49:03They're concentrating on their dam,
0:49:03 > 0:49:07strengthening it with rocks and plugging any leaks
0:49:07 > 0:49:10with weeds and mud to create a deep, wide pond.
0:49:12 > 0:49:16The water table here is rising so that they can reach out
0:49:16 > 0:49:18and get more of this food, the trees that grow around here,
0:49:18 > 0:49:21cotton woods, alders, willows.
0:49:21 > 0:49:25The beavers can now access all this untapped food...
0:49:27 > 0:49:30..without having to venture far onto dry land, where they are vulnerable.
0:49:36 > 0:49:41'Finally, Jeff spots what we've both been hoping to see.'
0:49:41 > 0:49:43- Oh, yeah.- There's a young one.
0:49:43 > 0:49:45- There's the young one.- Yes, yes.
0:50:00 > 0:50:04We've got our three young beavers right here, the three kits.
0:50:07 > 0:50:09- They're getting big.- They are.
0:50:09 > 0:50:10They're getting big fast.
0:50:13 > 0:50:17Mum's risky gamble appears to have paid off.
0:50:18 > 0:50:22This deep pond with a new lodge and plenty of food
0:50:22 > 0:50:25is everything the kits will need to thrive.
0:50:27 > 0:50:30They are so inquisitive, aren't they?
0:50:32 > 0:50:33And they're just...
0:50:33 > 0:50:36They're just fabulous to watch.
0:50:44 > 0:50:47The kits will stay with their parents for the next two years.
0:50:47 > 0:50:51In that time, they'll learn the engineering skills needed
0:50:51 > 0:50:54to build a dam and a lodge.
0:50:55 > 0:50:57The secret to the beavers' success
0:50:57 > 0:51:01is adapting the landscape to suit their needs.
0:51:04 > 0:51:09It's engineering on a scale that has only been surpassed by humans.
0:51:18 > 0:51:22Every year, the challenges in Yellowstone are getting greater,
0:51:22 > 0:51:26as climate change results in more extreme weather.
0:51:26 > 0:51:29Yellowstone's residents have developed
0:51:29 > 0:51:31clever strategies to survive.
0:51:31 > 0:51:33But the last animal I want to see
0:51:33 > 0:51:38is quickly running out of options as temperatures rise.
0:51:41 > 0:51:46I've come up to 3,000 metres and the fragile alpine zone.
0:51:50 > 0:51:56Only one specialist mammal is active up here all year round -
0:51:56 > 0:51:57the pika.
0:52:04 > 0:52:09And Kaitlyn Hanley is the hardy researcher who studies them.
0:52:13 > 0:52:16I've got glimpses of pika.
0:52:16 > 0:52:18Are they a member of the rabbit family?
0:52:18 > 0:52:19They call them rock rabbits.
0:52:19 > 0:52:21- SQUEAKING - Oh, there was one.- A little call?
0:52:21 > 0:52:23Yeah, that was a pika.
0:52:23 > 0:52:25Come on, Kaitlyn.
0:52:25 > 0:52:26- I want you to...- He's right there.
0:52:26 > 0:52:29Oh, my goodness, there he is!
0:52:41 > 0:52:45Pikas are thought to have evolved from ancestors in Siberia -
0:52:45 > 0:52:48one of the coldest places on Earth.
0:52:53 > 0:52:57Their odd appearance is all about keeping warm.
0:52:59 > 0:53:03A plump, round shape minimises surface heat loss
0:53:03 > 0:53:07and thick fur covers their entire bodies,
0:53:07 > 0:53:11even their toes.
0:53:13 > 0:53:16For pikas, summer is all about collecting food.
0:53:20 > 0:53:22I imagine that up here,
0:53:22 > 0:53:25the season where there is any food at all is pretty short.
0:53:25 > 0:53:28Yes, and they don't hibernate in the winter
0:53:28 > 0:53:31so they actually collect hay through the entire summer.
0:53:32 > 0:53:35And they'll use that as their food source during the winter.
0:53:35 > 0:53:37- So that's what they're doing now? - Yes, they are haying, yes.
0:53:39 > 0:53:41They'll get these huge hay piles under the rocks
0:53:41 > 0:53:43and they'll use that in the winter.
0:53:43 > 0:53:47And, yeah, they're the only mammal that doesn't hibernate up this high.
0:53:51 > 0:53:52And they can survive?
0:53:52 > 0:53:55Cos the snow must come here, what, in October?
0:53:55 > 0:53:57Yeah, so it would be October...
0:53:57 > 0:53:58Through to?
0:53:58 > 0:54:00March, May.
0:54:00 > 0:54:04So, they've got a matter of months to collect enough hay
0:54:04 > 0:54:07to get them through the whole of the winter.
0:54:07 > 0:54:11Yes. They're busy little bees, that's for sure.
0:54:14 > 0:54:16Pikas love a cool climate.
0:54:16 > 0:54:18Just a few hours' exposure
0:54:18 > 0:54:22to temperatures of 21 degrees can prove fatal.
0:54:23 > 0:54:28So they can only exist in Yellowstone above 2,000 metres.
0:54:30 > 0:54:35Soon, even here, they may have nowhere left to go.
0:54:36 > 0:54:40Because these animals are such high alpine specialists,
0:54:40 > 0:54:43they can't survive at the lower elevations.
0:54:43 > 0:54:45Does that make them particularly vulnerable
0:54:45 > 0:54:48- to things like climatic changes? - Absolutely.
0:54:48 > 0:54:50They are very sensitive to heat.
0:54:50 > 0:54:55And so as climate change and the habitat changes for them,
0:54:55 > 0:54:57they're going to move upslope.
0:54:59 > 0:55:02You're already upslope at this point, you can't go any further.
0:55:02 > 0:55:06And so, for the pika, you know, they don't have anywhere to move.
0:55:06 > 0:55:07They're running into the sky.
0:55:13 > 0:55:16Scientists have already seen pikas disappear
0:55:16 > 0:55:19from one-third of their former strongholds
0:55:19 > 0:55:21in warmer states to the south.
0:55:22 > 0:55:26But Yellowstone's high country still provides sanctuary.
0:55:26 > 0:55:29At least for now.
0:55:31 > 0:55:34I have hope. I don't think we should lose hope.
0:55:34 > 0:55:37Because they're too cute to go extinct!
0:55:38 > 0:55:41That's one very good reason
0:55:41 > 0:55:43we should all be there to save the pika
0:55:43 > 0:55:46is they're just too cute to go extinct!
0:55:47 > 0:55:49PIKA CALLS
0:55:55 > 0:55:59The arrival of autumn marks the end of the great thaw.
0:56:01 > 0:56:04We've seen how the dramatic seasonal changes
0:56:04 > 0:56:07affected Yellowstone's wildlife.
0:56:07 > 0:56:10The mild winter meant the wolves struggled
0:56:10 > 0:56:13to hunt strong, well-fed prey.
0:56:15 > 0:56:16And many went hungry.
0:56:16 > 0:56:19WOLF HOWLS
0:56:19 > 0:56:23But in the summer, they used their cunning
0:56:23 > 0:56:26to find food and keep their pups alive.
0:56:29 > 0:56:33The beavers survived the spring run-off
0:56:33 > 0:56:38and were able to build an entirely new home to raise their three kits.
0:56:42 > 0:56:45Our great grey owl runt beat all the odds
0:56:45 > 0:56:47and fledged with its two siblings...
0:56:50 > 0:56:54..giving this vulnerable population a much-needed boost.
0:56:56 > 0:56:59The grizzly bears' race to fatten up started early
0:56:59 > 0:57:02with the mild winter conditions.
0:57:02 > 0:57:07The wet spring and early green-up revealed a bounty of food.
0:57:07 > 0:57:12But by summer, they had to use all their resourcefulness to survive.
0:57:14 > 0:57:18This has been a magical window into the lives of wildlife
0:57:18 > 0:57:21in a truly spectacular landscape.
0:57:23 > 0:57:26We've also seen a bigger picture unfold,
0:57:26 > 0:57:29as scientists try to predict
0:57:29 > 0:57:33what the future for Yellowstone will look like as the climate shifts.
0:57:35 > 0:57:38I think what we do know is all of it's going to change
0:57:38 > 0:57:40and it's changing pretty rapidly
0:57:40 > 0:57:43and we don't really know how it's going to change.
0:57:43 > 0:57:44There will be some good and some bad,
0:57:44 > 0:57:47depending on what species you are, as climate change continues.
0:57:49 > 0:57:53There are still many challenges ahead.
0:57:54 > 0:57:58But if there's one thing that all of Yellowstone's animals share,
0:57:58 > 0:58:03it's their incredible ability to adapt to extreme change.
0:58:05 > 0:58:09And this will give them the best possible chance to survive,
0:58:09 > 0:58:11whatever the future brings.