0:00:15 > 0:00:17Meet Sivuqaq...
0:00:23 > 0:00:27..an 18-year-old, larger-than-life Pacific walrus...
0:00:29 > 0:00:31..who loves his food.
0:00:37 > 0:00:41And a well fed walrus...
0:00:41 > 0:00:42is a happy walrus.
0:00:49 > 0:00:52By now, he should be a dad...
0:00:54 > 0:00:56..but things haven't worked out.
0:00:58 > 0:01:00Which is where Holley Muraco comes in.
0:01:02 > 0:01:05Together, they have a very special relationship.
0:01:05 > 0:01:06Kiss. Good boy.
0:01:08 > 0:01:10An expert on animal reproduction,
0:01:10 > 0:01:14Sivuqaq is proving to be her toughest challenge to date.
0:01:16 > 0:01:20In zoos around the world, even pandas have been bred
0:01:20 > 0:01:23more successfully than walruses,
0:01:23 > 0:01:26so Holly is trying the near impossible.
0:01:29 > 0:01:33The secret of walrus love is a mystery, but perhaps the clues
0:01:33 > 0:01:38to success lie in exploring the lives of Sivuqaq's wild cousins.
0:01:38 > 0:01:42Could they hold the key to helping him have a family of his own?
0:01:46 > 0:01:48I think Sivuqaq is going to become a dad this year.
0:01:48 > 0:01:52He's ready and we're definitely ready to have
0:01:52 > 0:01:54that little bundle of joy walrus.
0:02:04 > 0:02:06This is Ukuk, her name means Blubber,
0:02:06 > 0:02:11and this is Siku, which is Eskimo for ice.
0:02:11 > 0:02:13This is Keylu, her name means bark.
0:02:13 > 0:02:16And this big guy right here, this is Sivuqaq,
0:02:16 > 0:02:20which is the native Eskimo term for the village of Gambol,
0:02:20 > 0:02:23which is where we got these guys.
0:02:25 > 0:02:27It all began in 1994.
0:02:33 > 0:02:37All these young walruses are orphans, their mothers having
0:02:37 > 0:02:40been killed by hunters in the wild wastes of Alaska.
0:02:45 > 0:02:49They were brought to Six Flags Discovery Kingdom in California,
0:02:49 > 0:02:52where they were adopted by surrogate parents
0:02:52 > 0:02:54who cared for them as they grew up.
0:02:58 > 0:03:01If they'd not been rescued, they would have died young.
0:03:08 > 0:03:11Sivuqaq is now three-and-a-half metres long,
0:03:11 > 0:03:13and weighs 1,000 kilograms.
0:03:14 > 0:03:16He's the park's main attraction.
0:03:39 > 0:03:42For the past six years, he's shared his life with scientist
0:03:42 > 0:03:43Holley Muraco.
0:03:47 > 0:03:50During that time, they have forged quite a bond.
0:03:54 > 0:03:55Good boy.
0:03:57 > 0:04:02So these walruses respond a lot to blowing in their nose, so to speak.
0:04:02 > 0:04:03All right.
0:04:03 > 0:04:07DEEP GROWLING
0:04:07 > 0:04:09It's walrus etiquette here that you walk in,
0:04:09 > 0:04:11and it's rude if you don't say hello.
0:04:11 > 0:04:14So you blow in their nose, they know who you are,
0:04:14 > 0:04:19they get an idea of what's going on and then everything is OK.
0:04:22 > 0:04:27Sivuqaq shares his Californian home with the two female orphans
0:04:27 > 0:04:29who made it to adulthood.
0:04:37 > 0:04:38OK, Ukuk.
0:04:39 > 0:04:42Ukuk is the shy, modest, retiring one of the two.
0:04:45 > 0:04:47Whistle!
0:04:47 > 0:04:49LOW WHISTLING
0:04:49 > 0:04:51Siku has a cheeky toothless grin.
0:04:51 > 0:04:54Her tusks were removed after an infection.
0:04:56 > 0:04:58She's much more blase and easy going.
0:05:03 > 0:05:06The girls are very sharp, they're very smart animals,
0:05:06 > 0:05:08even he's very smart.
0:05:08 > 0:05:10Yes, you are!
0:05:10 > 0:05:13But his brain tends to check out sometimes,
0:05:13 > 0:05:15especially when he's hormonal and he's in rut,
0:05:15 > 0:05:19and he's a bit of a knuckle-head. He's not all there.
0:05:20 > 0:05:23He's getting ready to blow some snot.
0:05:25 > 0:05:28Walruses are truly remarkable animals.
0:05:28 > 0:05:32LOUD GROWL
0:05:34 > 0:05:38Their name is thought to come from a combination of whale and horse.
0:05:38 > 0:05:42There are Pacific and Atlantic walruses living in the Arctic seas
0:05:42 > 0:05:44around the North Pole.
0:05:44 > 0:05:47They belong to the same family as seals and sea lions.
0:05:47 > 0:05:51Both males and females have whiskers
0:05:51 > 0:05:56and tusks which they use to drag themselves out of the water.
0:05:56 > 0:05:59They can weigh the same as a small family car,
0:05:59 > 0:06:05but we still know very little about how they live their lives.
0:06:08 > 0:06:11Sivuqaq is helping to change all that.
0:06:11 > 0:06:16After almost 20 years of scrutiny by US scientists,
0:06:16 > 0:06:21he is now the most studied walrus ever, but one thing
0:06:21 > 0:06:26in particular remains mysterious - their breeding behaviour.
0:06:30 > 0:06:33Holley wants to change this and help Sivuqaq become a dad.
0:06:35 > 0:06:37She's working hard to make it happen.
0:06:44 > 0:06:46She has helped breed dolphins...
0:06:51 > 0:06:53..elephants...
0:06:57 > 0:06:59..giraffes...
0:07:02 > 0:07:04..and sea lions.
0:07:10 > 0:07:14But breeding walruses is proving to be a different kettle of fish.
0:07:16 > 0:07:21The reason why it's so important to be able to breed walruses in zoos
0:07:21 > 0:07:25is because every zoo is always striving to be self-sustaining,
0:07:25 > 0:07:30so that we can have long-term populations, so understanding
0:07:30 > 0:07:35reproduction and being able to have babies in a zoo is very important.
0:07:38 > 0:07:42Male and female walruses have been housed together in US zoos
0:07:42 > 0:07:44and parks for almost 80 years,
0:07:44 > 0:07:49yet, in all that time, there have been just 15 live births.
0:07:55 > 0:07:59Routine hormone tests indicate Siku may be pregnant.
0:08:01 > 0:08:03Today is the day she'll find out.
0:08:03 > 0:08:06- Which way does she roll? - She'll probably roll your way.
0:08:06 > 0:08:10A pregnancy would be a really big event for everyone.
0:08:10 > 0:08:13- Oh, right.- Hold it. All right, Dessa.
0:08:13 > 0:08:17- Let's see what we see. - The timing is now.- Hold it.
0:08:17 > 0:08:18Good, Siku.
0:08:22 > 0:08:25Right now, it's not looking so good.
0:08:28 > 0:08:34I'm not seeing her uterus with much fluid at all.
0:08:39 > 0:08:41Well, that's disappointing.
0:08:41 > 0:08:43Yeah, that is.
0:08:45 > 0:08:48- But...- We try again.- ..we try again.
0:08:50 > 0:08:52You just need a baby in there.
0:08:57 > 0:09:02Unfortunately, we will not have any babies this spring.
0:09:02 > 0:09:05Neither Siku or Ukuk are currently pregnant.
0:09:05 > 0:09:08We had a lot of hopes that they were,
0:09:08 > 0:09:11but something wasn't quite right,
0:09:11 > 0:09:17and it's very disappointing, but unfortunately we are going to
0:09:17 > 0:09:21have to go into another breeding season and try all over again.
0:09:34 > 0:09:39Holley has been trying to breed the walruses for the past six years,
0:09:39 > 0:09:42and this isn't the first time she's been disappointed.
0:09:44 > 0:09:46One year in particular stands out,
0:09:46 > 0:09:48when she came to within a whisker of success.
0:09:51 > 0:09:54In 2010, Ukuk did get pregnant.
0:09:57 > 0:10:01About a week before she gave birth,
0:10:01 > 0:10:03the foetus died
0:10:03 > 0:10:05and Ukuk ultimately delivered a stillborn.
0:10:05 > 0:10:09The only way to say it is...Ukuk grieved.
0:10:13 > 0:10:16And for two days, she cared for the baby, she called to it,
0:10:16 > 0:10:19she held it, she nuzzled it
0:10:19 > 0:10:22and it was absolutely devastating.
0:10:37 > 0:10:41It took her a long time before she finally came back around
0:10:41 > 0:10:44and her wonderful personality started coming out again.
0:11:00 > 0:11:03After so many years of failure, heartache
0:11:03 > 0:11:07and disappointment, Holley really needs a breakthrough.
0:11:11 > 0:11:15And perhaps the clues are not here in the lab, but further afield...
0:11:20 > 0:11:25..with the wild walruses back in Sivuqaq's native home in Alaska.
0:11:31 > 0:11:33Here comes Sivuqaq.
0:11:33 > 0:11:36But she can't leave without saying goodbye to her special walrus.
0:11:36 > 0:11:39Hey, buddy, how's it going?
0:11:44 > 0:11:50We have very nosy walruses that love to see everything that we do.
0:11:51 > 0:11:54All right, Sivuqaq, I have to go to Alaska.
0:11:56 > 0:12:00I am going to go learn about wild walruses.
0:12:00 > 0:12:03I'm going to miss you, but the girls are going to feed you and feed you
0:12:03 > 0:12:06and feed you while I'm gone, and I will see you when I get back.
0:12:06 > 0:12:09LOUD SPLUTTERING
0:12:12 > 0:12:14Holley's heading in search of a haul out -
0:12:14 > 0:12:17a mass gathering of male walruses,
0:12:17 > 0:12:21which happens during the summer months on remote beaches.
0:12:21 > 0:12:25It's what Sivuqaq would be doing in the wild.
0:12:29 > 0:12:32Holley begins her journey with a 2,000 mile flight
0:12:32 > 0:12:33to Anchorage, Alaska.
0:12:36 > 0:12:39From there, she takes a second flight to Lake Clark,
0:12:39 > 0:12:42before heading along the Alaskan Peninsular,
0:12:42 > 0:12:45which separates the Bering Sea from the North Pacific.
0:12:55 > 0:12:58As she heads further and further into the wilderness,
0:12:58 > 0:13:00the planes get ever smaller.
0:13:05 > 0:13:07And for good reason.
0:13:21 > 0:13:25She's heading to a walrus haul out at Cape Seniavin -
0:13:25 > 0:13:30a rugged sea-sculptured beach on the Bering Sea coast.
0:13:30 > 0:13:32And there are no runways out here,
0:13:32 > 0:13:36so the plane must be small enough to land on a narrow stretch of beach.
0:13:43 > 0:13:46Holley's never travelled this far north before.
0:13:48 > 0:13:51She's studied her walruses for six years,
0:13:51 > 0:13:53but has never seen one in the wild.
0:13:53 > 0:13:56GULLS CAW
0:13:58 > 0:14:00In recent years, this has become
0:14:00 > 0:14:03one of the most important haul out areas in the whole of Alaska.
0:14:04 > 0:14:07Its remoteness allows them to gather here safely,
0:14:07 > 0:14:11and Holley must take care not to disturb them.
0:14:14 > 0:14:17So, we're close enough to the walrus herd now to smell them.
0:14:17 > 0:14:22It's a pretty intense smell, they're not the cleanest animals.
0:14:22 > 0:14:25We're still approaching extremely cautiously,
0:14:25 > 0:14:27we just can't be too careful.
0:14:27 > 0:14:29There's just so little known about walruses.
0:14:29 > 0:14:32We have no idea how great their eyesight is
0:14:32 > 0:14:34or their sense of smell or hearing,
0:14:34 > 0:14:37but we do know they're very spooky animals
0:14:37 > 0:14:40and we have to be careful, so we're just approaching very slowly
0:14:40 > 0:14:43and cautiously, but, so far, they're just jostling among themselves
0:14:43 > 0:14:47and don't seem too concerned with our presence, at this time.
0:15:02 > 0:15:08See, very carefully, making sure I don't disturb them.
0:15:10 > 0:15:12Oh, my goodness.
0:15:14 > 0:15:17Absolutely amazing.
0:15:26 > 0:15:33There's about 150 to 200 Sivuqaqs lying together on this beach.
0:15:38 > 0:15:40Look at all that bulk.
0:15:42 > 0:15:46Oh, these guys easily outweigh Sivuqaq by at least 1,000 pounds.
0:16:01 > 0:16:05Oh, my goodness. Look at the size of that guy.
0:16:05 > 0:16:06Amazing.
0:16:17 > 0:16:20Sivuqaq probably wouldn't make it very long out here, I'm guessing.
0:16:20 > 0:16:23He's a bit too much of a pretty boy.
0:16:25 > 0:16:29The one thing that's so interesting about these male walruses is
0:16:29 > 0:16:33those large bumps that you see on these wild males
0:16:33 > 0:16:37all over their neck, and we don't see that on Sivuqaq.
0:16:37 > 0:16:41We sort of assumed that they're formed
0:16:41 > 0:16:44when they hit one another with their tusks,
0:16:44 > 0:16:47but there's another theory suggesting that it's just
0:16:47 > 0:16:50male walruses, as they reach maturity, develop them naturally,
0:16:50 > 0:16:52but then Sivuqaq's a mature male and he doesn't have any,
0:16:52 > 0:16:55so that's another walrus mystery.
0:17:08 > 0:17:11A red fox makes a guest appearance.
0:17:13 > 0:17:17The long arctic winter appears to have taken its toll,
0:17:17 > 0:17:20but the beach is a good place to scavenge for food.
0:17:21 > 0:17:26The walruses keep a close eye, as the fox gets closer.
0:17:29 > 0:17:31Despite their size, they're nervous.
0:17:42 > 0:17:43They're off.
0:17:43 > 0:17:45The fox has sent these giants,
0:17:45 > 0:17:49perhaps 300 times its own weight, running for cover.
0:17:56 > 0:17:59Surely one of the natural world's greatest mismatches.
0:18:04 > 0:18:07Seemingly unaware of the chaos she has caused, the fox checks out
0:18:07 > 0:18:10a dried up walrus carcass,
0:18:10 > 0:18:12then leaves a calling card
0:18:12 > 0:18:14to let everyone know whose territory this really is...
0:18:18 > 0:18:20..and exits stage left.
0:18:24 > 0:18:27With the walruses now all at sea,
0:18:27 > 0:18:30it's a good time to call it a day and head back to camp.
0:18:37 > 0:18:42Although late in the evening, there are still two hours of daylight left
0:18:42 > 0:18:46before the sun briefly dips below the horizon.
0:18:46 > 0:18:49It's easy to lose track of the time out here.
0:18:51 > 0:18:55This far north, summer lasts only three months,
0:18:55 > 0:19:00but the long days mean it's a time of great productivity.
0:19:01 > 0:19:05Plants photosynthesise all day and all night,
0:19:05 > 0:19:10and, for a few short months, the tundra blooms.
0:19:13 > 0:19:16For some animals, it's a chance to rear their young,
0:19:16 > 0:19:22but, for the walruses, it's the opposite - this is when they recharge
0:19:22 > 0:19:26their batteries, having barely eaten during the winter breeding season.
0:19:37 > 0:19:42Wild walruses feed by rooting along the sea bottom,
0:19:42 > 0:19:47foraging on over 60 different kinds of marine creatures.
0:19:51 > 0:19:58Clams are their favourite, which they find with their sensitive whiskers,
0:19:58 > 0:20:02excavate with jets of water, then suck out the meat.
0:20:03 > 0:20:07Each one is devoured in just six seconds.
0:20:07 > 0:20:09And up to 6,000 in a day.
0:20:17 > 0:20:20It may look destructive, but walrus feeding helps keep the Arctic seas
0:20:20 > 0:20:23amongst the richest in the world.
0:20:27 > 0:20:31Disturbing the sediment releases nutrients, which feed the fish.
0:20:31 > 0:20:34Their organic waste trickles back down to the seabed,
0:20:34 > 0:20:38feeding the clams and other creatures of the sea floor.
0:20:38 > 0:20:42This trickle down not only enriches life on the sea bottom,
0:20:42 > 0:20:46but ultimately provides more food for the walruses.
0:21:03 > 0:21:06During midsummer, this far north, it's hard to know where night ends
0:21:06 > 0:21:08and day begins,
0:21:08 > 0:21:12but it does mean Holley can make the most of her time with the herd.
0:21:19 > 0:21:22At the haul out, she discovers more big males
0:21:22 > 0:21:24dragging themselves out onto the beach.
0:21:41 > 0:21:44As they emerge from the cold water, they're a ghostly white,
0:21:44 > 0:21:48having redirected blood from their skin to their hearts
0:21:48 > 0:21:50and other internal organs.
0:21:55 > 0:22:01As they warm, blood returns to the surface and they turn pink.
0:22:04 > 0:22:06Those that have been beached the longest return
0:22:06 > 0:22:09to their characteristic rich ruddy-brown.
0:22:15 > 0:22:18But right now, there is no aggression.
0:22:18 > 0:22:21All these males are sort of in a big love-in right now.
0:22:21 > 0:22:24They're all very happy to be together.
0:22:24 > 0:22:28As the season progresses and their testosterone starts to rise,
0:22:28 > 0:22:31this is going to change dramatically.
0:22:40 > 0:22:43That change won't happen until later in the year,
0:22:43 > 0:22:48when shorter days trigger a dramatic shift in male walrus behaviour
0:22:48 > 0:22:53and they enter the rut - the peak of their sexual activity.
0:23:07 > 0:23:10Right now, in midsummer, these walruses could not be
0:23:10 > 0:23:12more different from Sivuqaq.
0:23:14 > 0:23:18One thing that's really clear is Sivuqaq is really out of sync.
0:23:18 > 0:23:21Right now, these males are not displaying
0:23:21 > 0:23:23any type of rut behaviour.
0:23:23 > 0:23:26It's a bachelor pad, they're all hanging out,
0:23:26 > 0:23:28they're gaining weight, they're resting,
0:23:28 > 0:23:31they're getting prepared for the breeding season.
0:23:31 > 0:23:33Just a week ago, when I left Sivuqaq,
0:23:33 > 0:23:37he still was maintaining rut behaviours and displaying
0:23:37 > 0:23:42and singing and trying to attract the females for breeding, and it's
0:23:42 > 0:23:46clearly out of sync with what his wild counterparts are doing.
0:23:59 > 0:24:03Holley heads back to California with an important task ahead of her.
0:24:03 > 0:24:08Somehow, she must switch Sivuqaq's sexually active period from
0:24:08 > 0:24:12summer to winter, to match the sexual peak of his female companions.
0:24:22 > 0:24:26Walruses' behaviour in the Arctic is set by the day length.
0:24:26 > 0:24:30Summer is the time for rest and relaxation.
0:24:30 > 0:24:34Winter, migrating and mating.
0:24:34 > 0:24:38But Sivuqaq is on California time.
0:24:38 > 0:24:42He has never experienced anything like the Arctic, so his rut
0:24:42 > 0:24:45happens in the spring and summer, rather than the autumn and winter.
0:24:45 > 0:24:51As a result, he, Siku and Ukuk are completely out of sync,
0:24:51 > 0:24:53like ships passing in the night.
0:24:55 > 0:24:56Hey, bud!
0:24:58 > 0:24:59How's it going?
0:25:02 > 0:25:05Holley must somehow match what is happening in the wild,
0:25:05 > 0:25:09so first begins to fatten him up.
0:25:14 > 0:25:16Time for the weigh-in.
0:25:16 > 0:25:19But how do you weigh a walrus?
0:25:23 > 0:25:25With a set of scales, of course...
0:25:26 > 0:25:28..extra large scales.
0:25:31 > 0:25:32I know.
0:25:34 > 0:25:38It would appear Sivuqaq is a little bashful about his bulk.
0:25:47 > 0:25:50Over the next four months, they must increase Sivuqaq's weight
0:25:50 > 0:25:55to around 1,600 kilograms - about the weight of a small family car.
0:25:57 > 0:26:01Sivuqaq is 24, 25 and he's up 33 pounds.
0:26:01 > 0:26:04There is still a very long way to go.
0:26:07 > 0:26:11Between meals, Sivuqaq gets a special treat,
0:26:11 > 0:26:14and an opportunity to show off another of his many talents.
0:26:20 > 0:26:23His suction is so strong, he makes easy work of turning
0:26:23 > 0:26:27a ten kilogram block of ice into a cool refreshing drink.
0:26:31 > 0:26:34Walruses use suction to feed.
0:26:35 > 0:26:37The tongue acts like a piston,
0:26:37 > 0:26:40first pushed forward to the front of the mouth
0:26:40 > 0:26:44and then quickly withdrawn, creating a vacuum.
0:26:46 > 0:26:49It's been said walruses can create enough suction to suck
0:26:49 > 0:26:55the skin off a seal, but Sivuqaq's friends at the park needn't worry -
0:26:55 > 0:26:57he'd much rather eat fish.
0:27:00 > 0:27:04Surrounding those powerful lips are the walruses'
0:27:04 > 0:27:07most characteristic feature - their moustache.
0:27:07 > 0:27:13Called vibrissae, they form a broad mat of up to 700 stiff bristles -
0:27:13 > 0:27:15highly sensitive feelers
0:27:15 > 0:27:20capable of detecting food beneath the silty sea bottom.
0:27:23 > 0:27:25Walruses are really oral animals.
0:27:25 > 0:27:30It makes sense cos, out in the wild, they're foraging for their food
0:27:30 > 0:27:33on the bottom and feeling for clams and different things.
0:27:33 > 0:27:36Here, we don't obviously have foraging for them,
0:27:36 > 0:27:39so, when we give them their fish and their clams to eat,
0:27:39 > 0:27:42they still enjoy foraging, so to speak,
0:27:42 > 0:27:46and so what Sivuqaq's doing right now is...
0:27:46 > 0:27:50He keeps a little bit of fish from the last bit that we feed him
0:27:50 > 0:27:52and he's essentially playing with it.
0:27:59 > 0:28:03Everybody thinks it's disgusting, it's really gross,
0:28:03 > 0:28:08but, again, it's a natural behaviour that they do,
0:28:08 > 0:28:12it's obviously an important part of their life,
0:28:12 > 0:28:17and if it's fun for him, then that's our problem to deal with.
0:28:21 > 0:28:26Sivuqaq is now getting through 30 kilograms of fish every day.
0:28:29 > 0:28:32Gorging like this prepares him physically for the rut,
0:28:32 > 0:28:35which lasts about three months.
0:28:35 > 0:28:39During that time, he will drastically lose his appetite,
0:28:39 > 0:28:42so the food he eats now will need to see him through.
0:28:45 > 0:28:47With his weight rapidly increasing,
0:28:47 > 0:28:50Holley can start the next stage of his treatment.
0:28:51 > 0:28:56Every week, Sivuqaq gets an injection of HCG -
0:28:56 > 0:28:58human chorionic gonadotropin.
0:28:58 > 0:29:01This is a precursor to testosterone...
0:29:03 > 0:29:06..so that his body can make natural testosterone.
0:29:06 > 0:29:11So, right now, Jessa is getting ready to give him the injection.
0:29:11 > 0:29:15She's going to prep his back, it's just got to go...
0:29:15 > 0:29:17Hold it.
0:29:17 > 0:29:20This is exactly the same medication that is used
0:29:20 > 0:29:22in human fertility treatments.
0:29:25 > 0:29:30Boosting his testosterone should artificially induce his rut,
0:29:30 > 0:29:33and hopefully get him in sync with the girls.
0:29:37 > 0:29:39But it takes two to tango,
0:29:39 > 0:29:42and Siku and Ukuk must also be ready at the right time.
0:29:45 > 0:29:48They only have a narrow window during which they can conceive -
0:29:48 > 0:29:52a matter of days - so timing will be everything.
0:29:53 > 0:29:57Holley runs regular checks to monitor how they are doing.
0:29:57 > 0:30:00- I'm ready. - All right, Siku, open. Hold it.
0:30:01 > 0:30:04Oh, good. So, one of the things we can do...
0:30:05 > 0:30:09..is take a simple swab of the inside of their mouth
0:30:09 > 0:30:11and around their tongue...
0:30:12 > 0:30:15Good, good girl.
0:30:15 > 0:30:18We usually get a couple of swabs' full,
0:30:18 > 0:30:21and this can be used to test hormone levels.
0:30:21 > 0:30:25- Really, science is boring?!- OK!
0:30:32 > 0:30:34Although still warm in California,
0:30:34 > 0:30:37things are beginning to cool down in the Arctic.
0:30:41 > 0:30:44The nights are now much longer than the days,
0:30:44 > 0:30:46and this change of season is triggering
0:30:46 > 0:30:48the start of the rut in the wild.
0:30:57 > 0:31:01So, to discover more about what happens next in wild walruses,
0:31:01 > 0:31:03Holley heads back out to Alaska.
0:31:14 > 0:31:17Having spent the last six months apart,
0:31:17 > 0:31:21the males and females are gradually coming back together.
0:31:21 > 0:31:25The males have left their summer haul out and swim north,
0:31:25 > 0:31:28while the females are floating south on the sea ice.
0:31:28 > 0:31:33Many will meet in the southern Bering Sea, around St Lawrence,
0:31:33 > 0:31:36which has been nicknamed the walrus capital of the world.
0:31:39 > 0:31:42This is the island where Sivuqaq, Siku and Ukuk
0:31:42 > 0:31:45were rescued as orphans, all those years ago -
0:31:45 > 0:31:48the place where it all began.
0:31:48 > 0:31:51- Welcome to Savoonga.- Thank you. - You're welcome.- Thank you.
0:32:06 > 0:32:09During the Cold War, St Lawrence Island
0:32:09 > 0:32:11was strategically important to the US,
0:32:11 > 0:32:14and home to a large military base.
0:32:20 > 0:32:23Now, this island community survives by hunting
0:32:23 > 0:32:26and harvesting what they can from the sea.
0:32:35 > 0:32:38Holley is here to find out more about the walrus's
0:32:38 > 0:32:40unique rutting behaviour...
0:32:43 > 0:32:46..but conditions are not looking good.
0:32:53 > 0:32:56The local people have told me that, normally,
0:32:56 > 0:33:00this time of year, there is ice out here,
0:33:00 > 0:33:03but, this year, there is no ice.
0:33:05 > 0:33:08Because the ice retreated so far north this summer,
0:33:08 > 0:33:11it takes longer to come back.
0:33:11 > 0:33:14Sea ice conditions can change quickly in the Bering Sea,
0:33:14 > 0:33:18so Holley has to be patient and hope that a shift in the wind
0:33:18 > 0:33:22direction will bring the ice sheets and the walruses closer to land.
0:33:25 > 0:33:28The stormy seas may not be ideal for walrus watching,
0:33:28 > 0:33:32but they are washing up a bumper harvest for the villagers,
0:33:32 > 0:33:35including a bizarre animal that resembles a fruit.
0:33:45 > 0:33:47This is a sea peach,
0:33:47 > 0:33:51and they have found these in walrus stomachs before.
0:33:51 > 0:33:54The native people,
0:33:54 > 0:34:01one of their favourite meals is to cook the sea peach alongside
0:34:01 > 0:34:02the walrus meat.
0:34:02 > 0:34:06It's a very special delicacy.
0:34:17 > 0:34:23Well, can you tell me about all of this wonderful food?
0:34:23 > 0:34:25Oh, these are walrus food.
0:34:25 > 0:34:28This is what the walruses eat... The clams.
0:34:28 > 0:34:31That's a big clam.
0:34:31 > 0:34:33We slice 'em up and eat 'em.
0:34:33 > 0:34:36Here is a... Here is a good one.
0:34:36 > 0:34:38Do you want to taste it? It's pretty good.
0:34:38 > 0:34:41All right, here goes.
0:34:41 > 0:34:43I'm eating it, real walrus food.
0:34:43 > 0:34:45I'm watching!
0:34:45 > 0:34:47Uh-huh, it's real good.
0:34:47 > 0:34:50- It is good.- Uh-huh.- Wow.
0:35:00 > 0:35:02Still no sign of any walruses.
0:35:02 > 0:35:05But if they're not here, then where are they?
0:35:09 > 0:35:13Female walruses and their young are normally spread out
0:35:13 > 0:35:15over thousands of square miles of sea ice.
0:35:21 > 0:35:25Over recent years, the Arctic ice has been reducing,
0:35:25 > 0:35:30forcing them to haul out on exposed beaches instead,
0:35:30 > 0:35:33and that can have dire consequences.
0:35:38 > 0:35:41In 2011, one of the largest walrus gatherings in living memory
0:35:41 > 0:35:44occurred at Point Lay, Alaska.
0:35:47 > 0:35:50Numbering nearly 20,000, this haul out
0:35:50 > 0:35:55accounted for almost a tenth of the entire Pacific walrus population.
0:36:00 > 0:36:03Far from safety in numbers, these mass haul outs
0:36:03 > 0:36:06result in the rapid spread of disease.
0:36:11 > 0:36:14But, most worrying of all
0:36:14 > 0:36:18were reports of hundreds of walruses trampled to death during stampedes.
0:36:30 > 0:36:34And wherever walruses come on land, they are vulnerable to
0:36:34 > 0:36:37attack by the Arctic's most fearsome predator.
0:36:56 > 0:37:00An adult walrus can weigh twice as much as a polar bear.
0:37:00 > 0:37:02It seems a daunting challenge,
0:37:02 > 0:37:06even for the world's largest land carnivore.
0:37:15 > 0:37:19The mothers put up a wall of hide and blubber to protect their calves.
0:37:29 > 0:37:32By rushing in, the bear spreads panic.
0:37:38 > 0:37:41In the chaos, some get separated.
0:37:46 > 0:37:49The bear spots an opportunity, but must avoid injury.
0:37:51 > 0:37:54Stabbing tusks could easily puncture a bear's skull.
0:37:59 > 0:38:01But, in this case, the walrus hide,
0:38:01 > 0:38:04which can be nearly ten centimetres thick,
0:38:04 > 0:38:06proves to be its greatest defence.
0:38:08 > 0:38:10The bear loses its grip
0:38:10 > 0:38:12and its chance of a big meal.
0:38:33 > 0:38:36On St Lawrence, the sea ice and the walrus
0:38:36 > 0:38:38still show no sign of arriving,
0:38:38 > 0:38:42so Holley takes this opportunity to visit some of the villagers.
0:38:45 > 0:38:48And all of these pieces here are fossilised?
0:38:48 > 0:38:50Uh-huh, these are fossilised...
0:38:50 > 0:38:53Joseph Akeya is a fisherman and a hunter.
0:38:55 > 0:38:57He also dives in these freezing waters
0:38:57 > 0:39:00to collect fossilised walrus remains.
0:39:00 > 0:39:02- Where someone has cut into it?- Yeah.
0:39:02 > 0:39:04By hand, probably.
0:39:04 > 0:39:07- This was found inland, somewhere. - Wow.
0:39:08 > 0:39:14So you see the walruses all year round, somewhere around here?
0:39:14 > 0:39:18Somewhere on the island, always, there's walruses somewhere.
0:39:18 > 0:39:20They're not going to be in one place,
0:39:20 > 0:39:22they're going to be moving,
0:39:22 > 0:39:25along with the wind, maybe,
0:39:25 > 0:39:30- along with the current, or their food.- Right.
0:39:30 > 0:39:33You say you go diving out here in this water
0:39:33 > 0:39:36and you have heard walruses?
0:39:36 > 0:39:38I have heard walruses.
0:39:38 > 0:39:42They make some kind of a whistling sound, like...
0:39:42 > 0:39:46HE MAKES LOW PITCH SOUND
0:39:46 > 0:39:49And then, after a while, like...
0:39:49 > 0:39:51Tuk-tuk-tuk-tuk-tuk-tuk.
0:39:51 > 0:39:55Maybe from their teeth or tusks, maybe.
0:39:55 > 0:39:58Uh-huh, but it's a knock?
0:39:58 > 0:40:00Like hammering something... Tuk-tuk-tuk...
0:40:02 > 0:40:07The sounds Joseph describes are very similar to those that Sivuqaq makes
0:40:07 > 0:40:11and village elder Larry Kava has also heard sounds
0:40:11 > 0:40:16and seen intimate walrus behaviour not recorded by science.
0:40:47 > 0:40:50- HIGH PITCHED SINGING:- Inya-ing-ing.
0:40:52 > 0:40:57Inya-ing-ing.
0:41:04 > 0:41:07It's time for Holley to leave.
0:41:07 > 0:41:11She hasn't seen a single walrus, but is still taking something home
0:41:11 > 0:41:14from this remote and extraordinary place.
0:41:17 > 0:41:21The importance of walrus song to their courtship has been confirmed
0:41:21 > 0:41:24by the Yupik hunters, and Holley will be listening
0:41:24 > 0:41:29to the calls of her Californian walruses with renewed interest.
0:41:34 > 0:41:37As the arctic winter approaches, the mating season begins,
0:41:37 > 0:41:40and the walrus song will peak.
0:41:40 > 0:41:44Perhaps sound could be the key to success.
0:41:59 > 0:42:03Back at the park, Sivuqaq's hormone treatment is making him
0:42:03 > 0:42:07increasingly vocal, just like the walruses in the wild.
0:42:07 > 0:42:11Sivuqaq's mood is extremely grumpy, irritable.
0:42:11 > 0:42:14I am going to be keeping my distance from him
0:42:14 > 0:42:16because he's very unpredictable right now,
0:42:16 > 0:42:20he is in...he's in the peak of his rut.
0:42:20 > 0:42:24SIVUQAQ MAKES CLICKING SOUNDS
0:42:24 > 0:42:28In the wild this is a very typical normal rut behaviour.
0:42:28 > 0:42:32SIVUQAQ GROWLS
0:42:32 > 0:42:36What we have to do during these few months when he's just grumpy,
0:42:36 > 0:42:40and irritable, and cranky, and unpredictable
0:42:40 > 0:42:46is just give him his space, give him his distance and wait him out.
0:42:46 > 0:42:50SIVUQAQ CLICKS MELODICALLY
0:42:50 > 0:42:53Sivuqaq can certainly knock out a tune.
0:42:53 > 0:43:00SIVUQAQ CONTINUES CLICKING
0:43:00 > 0:43:04HE GROWLS
0:43:04 > 0:43:06HE HISSES
0:43:06 > 0:43:09Scientists are just beginning to realise that the richness
0:43:09 > 0:43:14and complexity of walrus songs could rival that of whales.
0:43:16 > 0:43:19Now having heard it from the Yupik hunters,
0:43:19 > 0:43:22Holley knows that getting him singing at the right time
0:43:22 > 0:43:25could be vital to them breeding.
0:43:26 > 0:43:30HE GROWLS
0:43:30 > 0:43:34Sivuqaq has long been something of a drama queen.
0:43:34 > 0:43:39He has over 75 different sounds and often uses them to show off.
0:43:41 > 0:43:45In his younger days, Sivuqaq hit the heady heights of Hollywood.
0:43:46 > 0:43:50This began when Spielberg used his growl for the call
0:43:50 > 0:43:53of the T Rex in Jurassic Park,
0:43:53 > 0:43:56and continued with other voice roles in Star Wars,
0:43:56 > 0:43:59Lord Of The Rings and The Hobbit.
0:43:59 > 0:44:02Not content with his bit-part as a voice-over artist,
0:44:02 > 0:44:04he then stepped up to the plate,
0:44:04 > 0:44:09acting alongside Adam Sandler in Fifty First Dates.
0:44:16 > 0:44:20Now his unusual voice may just land him his biggest role yet -
0:44:20 > 0:44:23the romantic lead.
0:44:24 > 0:44:26Hold it, hold it.
0:44:28 > 0:44:31Time for Holley and her team to take some sperm to see
0:44:31 > 0:44:36if six months of treatment has helped get him ready to sire some pups.
0:44:36 > 0:44:39Hold it, hold it.
0:44:39 > 0:44:43Good Sivuqaq, good. Easy, good boy.
0:44:43 > 0:44:50Good, good boy, keep going, good, good boy, keep going, easy.
0:44:50 > 0:44:52- OK.- Good boy.
0:44:57 > 0:45:00Holy moly, sassy pants!
0:45:00 > 0:45:02Sivuqaq!
0:45:07 > 0:45:13Sivuqaq has just had his 18th birthday and should be in prime, sexual health
0:45:13 > 0:45:17but will he be at the peak of his sexual prowess?
0:45:23 > 0:45:31Well, the good news is we have plenty of sperm.
0:45:32 > 0:45:36So our efforts for making Sivuqaq go into rut
0:45:36 > 0:45:38has been successful
0:45:38 > 0:45:40and we have a really, really nice motility,
0:45:40 > 0:45:43that means the sperm is moving in a forward direction
0:45:43 > 0:45:46and most of it is alive and looking really good.
0:45:46 > 0:45:49And this is what we want for optimal fertility.
0:45:49 > 0:45:53So with our females coming into oestrus, this is exactly what
0:45:53 > 0:45:56we want to see, so really good news here.
0:46:00 > 0:46:04HE GROWLS
0:46:04 > 0:46:12GROWLING ECHOES ACROSS PARK
0:46:19 > 0:46:24Sivuqaq is physically ready, but now must be in full voice
0:46:24 > 0:46:30and at his most charming during Siku and Ukuk's short breeding window.
0:46:47 > 0:46:52Holley has placed microphones around their pool to monitor their sounds.
0:46:52 > 0:46:58RHYTHMIC KNOCKING SOUND
0:46:58 > 0:47:02The sound that Sivuqaq is making right now...
0:47:04 > 0:47:07..is a rhythmic knocking sound.
0:47:07 > 0:47:12And if you look carefully at his head while he's knocking,
0:47:12 > 0:47:15you can see his head vibrating and we don't understand
0:47:15 > 0:47:18exactly how he's producing those sounds.
0:47:20 > 0:47:22The other sound that he loves to make
0:47:22 > 0:47:24is he claps his flippers together.
0:47:24 > 0:47:29RHYTHMIC CLAPPING OF FLIPPERS
0:47:29 > 0:47:32And there's a rhythm to the clapping.
0:47:32 > 0:47:35I don't have any rhythm but he's very good at it
0:47:35 > 0:47:38and sometimes he'll knock and he'll clap at the same time.
0:47:38 > 0:47:42CONTINUES CLAPPING
0:47:42 > 0:47:46It's a display that he does to make himself look big and strong.
0:47:53 > 0:47:58And you can feel the vibration through this very thick glass.
0:47:58 > 0:48:00It's very powerful.
0:48:08 > 0:48:11And now he's inflating his throat sacs.
0:48:18 > 0:48:21Walruses have these enormous sacs in their necks
0:48:21 > 0:48:25that they can fill with air and it makes a really interesting
0:48:25 > 0:48:28and almost beautiful sound when they fill it full of air.
0:48:28 > 0:48:32GENTLE GURGLING
0:48:36 > 0:48:39Now he's clapping and knocking at the same time.
0:48:39 > 0:48:42CONTINUES CLAPPING AND KNOCKING
0:48:50 > 0:48:52It's a remarkable thing to hear.
0:48:52 > 0:48:54You can imagine that, in the wild,
0:48:54 > 0:48:57the males are sending out all of these sounds
0:48:57 > 0:49:00and they're travelling for miles attracting the females.
0:49:01 > 0:49:04Sivuqaq is in full song.
0:49:04 > 0:49:08If Holley's work has been a success, then all she can do now
0:49:08 > 0:49:10is sit back and wait for the magic to happen.
0:49:16 > 0:49:18SIVUQAQ CLAPS
0:49:53 > 0:49:57What happens during walrus mating is one of the best-kept secrets
0:49:57 > 0:49:59in the natural world.
0:49:59 > 0:50:01Until now.
0:50:06 > 0:50:07This is walrus love.
0:50:13 > 0:50:16It's not the most gentle thing you'll ever see
0:50:16 > 0:50:20but when you're 3,000 and 2,000 pounds you can handle it.
0:50:24 > 0:50:28This is the first time that this behaviour has ever been filmed.
0:50:34 > 0:50:37In the wild, it happens in complete darkness around the edge
0:50:37 > 0:50:41of the sea ice in the frozen Bering Sea.
0:50:56 > 0:50:59In six years of studying these guys
0:50:59 > 0:51:01I have never seen what we've just witnessed.
0:51:01 > 0:51:04Ukuk must be right at the peak of her oestrus
0:51:04 > 0:51:07because she came over, solicited Sivuqaq, which we've seen before,
0:51:07 > 0:51:10but then they immediately started copulating right here
0:51:10 > 0:51:14in front of the window and it lasted for at least five minutes
0:51:14 > 0:51:18and the way they were together was remarkable.
0:51:18 > 0:51:20HE GURGLES
0:51:20 > 0:51:22At last Holley has seen them mating,
0:51:22 > 0:51:25proof that her treatments are working.
0:51:25 > 0:51:29And her microphones have revealed something new to science.
0:51:33 > 0:51:36Not only is Sivuqaq singing to the girls,
0:51:36 > 0:51:39it sounds like the girls are singing back.
0:51:42 > 0:51:46Siku, your voice was really impressive
0:51:46 > 0:51:48when you were singing your song,
0:51:48 > 0:51:51but Sivuqaq really seemed to like Ukuk
0:51:51 > 0:51:54and hers was really different and interesting,
0:51:54 > 0:51:56so, I don't know, what does it mean?
0:51:56 > 0:51:59GURGLING
0:51:59 > 0:52:02This sound is Ukuk calling.
0:52:08 > 0:52:11Siku, do you remember this?
0:52:11 > 0:52:14Do you remember making all those sounds? You were singing.
0:52:18 > 0:52:21This is Siku with a very different call.
0:52:21 > 0:52:23LOW HOWLING
0:52:23 > 0:52:27And this has never been documented before and we have no idea
0:52:27 > 0:52:30if this takes place in the wild or if it doesn't, but this is
0:52:30 > 0:52:34really exciting information, so I don't know, what does it mean?
0:52:34 > 0:52:38Does it mean anything at all? What do you think?
0:52:38 > 0:52:41THEY WHISTLE
0:52:41 > 0:52:43I sure wish you two could talk.
0:52:46 > 0:52:47But there's still a long way to go
0:52:47 > 0:52:50until she hears the pitter-patter of tiny fins.
0:52:55 > 0:52:58From conception to birth takes up to 16 months.
0:52:58 > 0:53:01Until recently this was thought to be
0:53:01 > 0:53:04one of the longest pregnancies in the natural world.
0:53:04 > 0:53:08But research now suggests that female walruses
0:53:08 > 0:53:12delay implanting the fertilised egg into the womb for four months,
0:53:12 > 0:53:14so that the calf is born in the spring
0:53:14 > 0:53:19when the weather conditions are best suited to its survival.
0:53:31 > 0:53:34In the wild, mothers and calves live in nursery groups
0:53:34 > 0:53:39well away from the large herds of big clumsy males.
0:53:45 > 0:53:48The calves can swim within hours of birth,
0:53:48 > 0:53:51but at first rarely stray far from their mother's side,
0:53:51 > 0:53:54who protect them by holding them close.
0:54:05 > 0:54:08They stay together for up to three years,
0:54:08 > 0:54:10forging a bond that provides an opportunity to learn
0:54:10 > 0:54:13life's most important lessons,
0:54:13 > 0:54:19such as how to communicate, to share food, nurse one another's young,
0:54:19 > 0:54:22and to help other herd members when under attack.
0:54:33 > 0:54:35If either Siku or Ukuk give birth,
0:54:35 > 0:54:38then Holley must be part of the nursery group.
0:54:38 > 0:54:42It's so she can keep a close eye on the health of the calf.
0:54:42 > 0:54:44So, complete trust is essential,
0:54:44 > 0:54:47and she gains that by playing with them.
0:54:50 > 0:54:54Playtime with these girls is a very important bonding time,
0:54:54 > 0:54:57and this is going to be really good if we do end up with
0:54:57 > 0:54:59two pregnant walruses and two babies.
0:54:59 > 0:55:01We're going to want to be able to get close
0:55:01 > 0:55:03to these...these calves.
0:55:03 > 0:55:07We need them to trust us, to know that it's going to be OK
0:55:07 > 0:55:09if they share their calves with us.
0:55:15 > 0:55:18There's nothing more to do now except relax
0:55:18 > 0:55:20and wait for nature to take its course.
0:55:30 > 0:55:31On your back.
0:55:33 > 0:55:35Hold it.
0:55:36 > 0:55:40It's April. Winter has turned to spring
0:55:40 > 0:55:43and the eggs should now be implanted into the womb.
0:55:44 > 0:55:45Holley's about to find out
0:55:45 > 0:55:48if six years of research has been a success.
0:55:49 > 0:55:52Right now, I'm checking...
0:55:52 > 0:55:54Siku's uterus.
0:55:56 > 0:55:57She actually has two uterine horns,
0:55:57 > 0:55:59I have to check both of them, the right and the left,
0:55:59 > 0:56:02to see if we see any fluid start to build up.
0:56:02 > 0:56:06This will be the first indication that we're on our way towards a pregnancy.
0:56:09 > 0:56:13This is all very new. There is no information out there to help us.
0:56:13 > 0:56:14Nobody's written a book that says,
0:56:14 > 0:56:16"This is what you should be looking for,"
0:56:16 > 0:56:19so we're sort of writing the book as we go.
0:56:30 > 0:56:32Siku's very nosy.
0:56:34 > 0:56:37She always wants to know what's happening with her ultrasounds.
0:56:37 > 0:56:41Now, on Siku today, I did see signs that she may have
0:56:41 > 0:56:44the very start to some uterine fluid.
0:56:44 > 0:56:46What do you think, Siku?
0:56:48 > 0:56:50You're not talking, are you? No.
0:56:50 > 0:56:54But right here I have a bright white patch
0:56:54 > 0:56:57and a bright white patch that indicates that I could be
0:56:57 > 0:57:01looking at about two centimetres worth of fluid in her uterine horn.
0:57:03 > 0:57:07So if that's the case, then as I continue to watch this each week
0:57:07 > 0:57:12it will grow and hopefully we'll see a baby in that left uterine horn.
0:57:13 > 0:57:18Siku looks great and Ukuk looks great, they both are just perfect.
0:57:22 > 0:57:26One pregnant walrus would be a great result.
0:57:26 > 0:57:28Two would be extraordinary.
0:57:30 > 0:57:33Holley's work is providing invaluable insights
0:57:33 > 0:57:36into the breeding biology of these unique creatures,
0:57:36 > 0:57:39but, best of all, it's helping a friend.
0:57:44 > 0:57:47I think Sivuqaq is going to become a dad this year.
0:57:47 > 0:57:49I feel confident.
0:57:49 > 0:57:51He is ready and we're definitely ready
0:57:51 > 0:57:54to have that little bundle of joy walrus.
0:57:58 > 0:58:01From a four-month-old, 70 kilogram orphan,
0:58:01 > 0:58:05to an 18-year-old, two tonne potential father.
0:58:05 > 0:58:08Now that IS something to shout about.
0:58:08 > 0:58:16HE GROWLS LOUDLY
0:58:47 > 0:58:49Subtitles by Red Bee Media Ltd