0:00:13 > 0:00:15Hello!
0:00:28 > 0:00:32I'm here in Mexico where these whales come to breed
0:00:32 > 0:00:35and to give birth to beautiful babies like this.
0:00:37 > 0:00:44This grey whale calf is about three months old, but in a few days
0:00:44 > 0:00:47this mother and calf are going to head north
0:00:47 > 0:00:51on one of the longest migrations on the planet.
0:00:51 > 0:00:55This is the story of the grey whale.
0:01:06 > 0:01:07It may not look that way,
0:01:07 > 0:01:12but you're looking at one of nature's supreme athletes.
0:01:12 > 0:01:15Grey whales migrate over 12,000 miles -
0:01:15 > 0:01:17that's halfway round the planet -
0:01:17 > 0:01:19every single year.
0:01:21 > 0:01:25Big animals, big numbers...
0:01:25 > 0:01:29It's a difficult and dangerous journey for all the whales,
0:01:29 > 0:01:31but especially for the newborn calves.
0:01:31 > 0:01:34They'll face constant threats.
0:01:37 > 0:01:41In fact, only half the calves will make it to their first birthday.
0:01:43 > 0:01:45But why do they do it?
0:01:45 > 0:01:48Why do they have to go so far?
0:01:48 > 0:01:51And how exactly do they make such an immense journey?
0:01:53 > 0:01:56It's only by making the journey myself
0:01:56 > 0:01:58that I can answer these questions.
0:01:58 > 0:02:03So my mission is to try and travel with the whales as they take on
0:02:03 > 0:02:07the longest journey of any mammal on the planet.
0:02:12 > 0:02:14This will be a tough journey for me too.
0:02:14 > 0:02:16Who knows what problems we're going to face?
0:02:38 > 0:02:40Our route will take the whales and me
0:02:40 > 0:02:44along the entire Pacific coast of North America.
0:02:44 > 0:02:45Right now,
0:02:45 > 0:02:48the whales are at the most southerly point of their travels.
0:02:48 > 0:02:50Why are they here?
0:02:50 > 0:02:52Well, these lagoons on the coast of Mexico
0:02:52 > 0:02:55are the perfect place for them to give birth.
0:02:55 > 0:03:00The water is warm and calm and there are very few predators.
0:03:00 > 0:03:02But there's a big problem -
0:03:02 > 0:03:05while it might be a great place to give birth,
0:03:05 > 0:03:09there's virtually nothing for them to eat here.
0:03:09 > 0:03:12These mothers are effectively running on empty
0:03:12 > 0:03:15and are living off their fat reserves.
0:03:20 > 0:03:23Come on, let's have a look at you.
0:03:23 > 0:03:27'The amazing thing is that whilst they're in the lagoons,
0:03:27 > 0:03:30'the whales actually chose to come to boats.
0:03:30 > 0:03:33'They feel relaxed and safe here.'
0:03:33 > 0:03:35Whoa, a big Mama!
0:03:35 > 0:03:40Look at that! That is amazing.
0:03:40 > 0:03:46This is the closest encounter you'll ever get with a completely wild,
0:03:46 > 0:03:48enormous creature.
0:03:48 > 0:03:50Ha-ha-ha!
0:03:50 > 0:03:53Nobody can say for sure why they do it,
0:03:53 > 0:03:55maybe it's because of the parasites.
0:03:55 > 0:03:58They like them scrapped off,
0:03:58 > 0:04:00maybe it's boredom.
0:04:00 > 0:04:03Whatever it is, they get something out of it.
0:04:03 > 0:04:06Ugh!
0:04:08 > 0:04:11Since whale watching began here, the whales have become
0:04:11 > 0:04:13extraordinarily trusting and inquisitive,
0:04:13 > 0:04:19yet 100 years ago, grey whales were hunted to the brink of extinction.
0:04:24 > 0:04:27It's actually a wonderful success story.
0:04:27 > 0:04:33After hunting was banned, the whales made an amazing recovery.
0:04:33 > 0:04:38There are now probably as many greys as there were before hunting began.
0:04:38 > 0:04:41Look at you...
0:04:41 > 0:04:42looking at me!
0:04:44 > 0:04:47Look at mum. Mum's pushing it towards me.
0:04:50 > 0:04:54Mum is saying, "Go on have a go. Meet them."
0:04:55 > 0:04:57You must be a very proud mum.
0:05:02 > 0:05:05Grey whales are one of nature's super mums.
0:05:05 > 0:05:10Mother and calf have a 6,000-mile journey ahead of them
0:05:10 > 0:05:14and mum will be looking after her baby every step of the way.
0:05:18 > 0:05:19But right now,
0:05:19 > 0:05:24her priority is to get her calf ready for this epic journey.
0:05:24 > 0:05:29The calf fuels up on mother's milk and it's awesome stuff.
0:05:29 > 0:05:34It's so rich the calf puts on around 27 kg every day.
0:05:41 > 0:05:43Young grey whales are not strong swimmers
0:05:43 > 0:05:47and their mothers have often been seen getting underneath them
0:05:47 > 0:05:50and lifting them gently to the surface for a breather.
0:05:56 > 0:06:00But these youngsters need to get into training fast,
0:06:00 > 0:06:01and mums help here too.
0:06:01 > 0:06:05They'll lead their calves to the entrance of the lagoon
0:06:05 > 0:06:10to swim against the incoming tide in a kind of aquatic gymnasium.
0:06:14 > 0:06:18There's such a strong bond between a grey whale mother and its baby,
0:06:18 > 0:06:21which never strays far from its side.
0:06:21 > 0:06:24But this intimacy does have a downside.
0:06:27 > 0:06:30Within days of being born, the calf is covered with young barnacles
0:06:30 > 0:06:34and is teeming with lice, which crawl across from its mother.
0:06:34 > 0:06:38The baby will carry these harmless hitchhikers
0:06:38 > 0:06:40for the rest of its life.
0:06:40 > 0:06:43All these barnacles are newly forming.
0:06:43 > 0:06:47You can see here and you can see hairs on the chin as well.
0:06:47 > 0:06:51As all mammals have hairs, so do whales.
0:06:51 > 0:06:54Look at that. That there is a whale louse.
0:06:54 > 0:06:57It's gripped hold of my finger.
0:06:57 > 0:06:59They really do grip on as well.
0:06:59 > 0:07:01Let go!
0:07:02 > 0:07:04No, it's stuck to that finger now.
0:07:04 > 0:07:07I think I've now got my own complement
0:07:07 > 0:07:10of whale parasites for life.
0:07:10 > 0:07:12Whoa!
0:07:14 > 0:07:16That was whale snot right in the face.
0:07:16 > 0:07:18WHALE BELLOWS
0:07:18 > 0:07:23- What a funny noise. - HE GIGGLES
0:07:24 > 0:07:27Sounds like my brother in the bath!
0:07:33 > 0:07:36What an extraordinary day!
0:07:36 > 0:07:38As always on Incredible Journeys,
0:07:38 > 0:07:41I'm going to be keeping my own video diary throughout the trip.
0:07:44 > 0:07:47There's only been a couple of times in my life
0:07:47 > 0:07:52when animals, true wild animals, have come up to me and said,
0:07:52 > 0:07:55"Hello, here I am, come and play."
0:07:57 > 0:08:04Um, I am a scientist, I love to sort of work out why animals behave in the way they do,
0:08:04 > 0:08:08but I also love the fact that science can't explain everything.
0:08:08 > 0:08:10What happened today...
0:08:10 > 0:08:14is a mystery. It's wonderful, it's really nice.
0:08:14 > 0:08:18It's... You know, you can look at it on a scientific basis
0:08:18 > 0:08:21and try and work out what the whales are getting out of it
0:08:21 > 0:08:25or you can look at it on an emotional basis and it's an incredible experience.
0:08:33 > 0:08:37It's all very well saying I'm going to try and travel with the whales,
0:08:37 > 0:08:42but no-one has ever tried to follow individual grey whales before
0:08:42 > 0:08:45on their entire migration.
0:08:45 > 0:08:47So just exactly how am I going to do it?
0:08:47 > 0:08:50Well, this is where the scientists come in.
0:08:50 > 0:08:53We'll be joining a team of scientists
0:08:53 > 0:08:56who have a research project to track the whales
0:08:56 > 0:09:00by placing harmless satellite transmitters on mothers.
0:09:00 > 0:09:02The transmitters should tell us
0:09:02 > 0:09:05exactly where the whales are along their journey.
0:09:06 > 0:09:09But since this hasn't been attempted before,
0:09:09 > 0:09:13no-one knows if it's even possible.
0:09:16 > 0:09:20The whole process of putting the transmitters on the whales
0:09:20 > 0:09:21is highly skilled.
0:09:21 > 0:09:26And Professor Bruce Mate from Oregon State University is the expert.
0:09:26 > 0:09:30He's been studying these whales for 25 years.
0:09:35 > 0:09:39With great care, Bruce places a tag on the mother.
0:09:41 > 0:09:45It only weighs 150 grams and probably feels no more
0:09:45 > 0:09:49than a pinprick to a 35-ton adult whale.
0:09:49 > 0:09:54The red outer sleeve falls away leaving the small tag behind.
0:10:03 > 0:10:08At least a dozen mothers need to be tagged for this scientific project,
0:10:08 > 0:10:12but we need two particular whales to try and follow -
0:10:12 > 0:10:14special mums.
0:10:17 > 0:10:19They have to have clear and distinctive markings
0:10:19 > 0:10:22to help us spot them as they travel up the coast.
0:10:28 > 0:10:31We'll be checking in with Bruce to get the locations
0:10:31 > 0:10:34of the whales throughout their journey.
0:10:34 > 0:10:39What are our chances, do you think of finding our whales on the migration if we go out?
0:10:39 > 0:10:42Well, actually our chances are pretty good
0:10:42 > 0:10:44because we do have radio tags on them.
0:10:44 > 0:10:47Otherwise it would be a needle in a haystack and we wouldn't have much chance.
0:10:47 > 0:10:50And how successful are the tags, you know?
0:10:50 > 0:10:52Have you used them in greys before?
0:10:52 > 0:10:54Actually, this is the first time we've used
0:10:54 > 0:10:56this technology on grey whales.
0:10:56 > 0:11:00We've used it on blue whales, humpbacks, fin whales and sperm whales
0:11:00 > 0:11:04and we've had a little bit of experience there, so we're hopeful that we're gonna see
0:11:04 > 0:11:08at least half of these tags last for the entire migration.
0:11:11 > 0:11:15It's amazing...you end up filming a lot of researchers
0:11:15 > 0:11:18working in the field when you study wildlife,
0:11:18 > 0:11:23but rarely do you get in to a project right at the beginning
0:11:23 > 0:11:26where you're actually finding out, real time,
0:11:26 > 0:11:30new knowledge and this is one of those occasions.
0:11:30 > 0:11:32They live hidden lives
0:11:32 > 0:11:35that we are hopefully going to get a real look at.
0:11:35 > 0:11:39We're going to get a real understanding
0:11:39 > 0:11:42of how they make this incredible journey.
0:11:45 > 0:11:48The first results show that mothers and calves
0:11:48 > 0:11:51don't all leave on migration at once.
0:11:51 > 0:11:55Whilst some mothers have already left and started their journey,
0:11:55 > 0:11:57others are still hanging around in the lagoons.
0:12:05 > 0:12:07When to leave is perhaps the most difficult decision
0:12:07 > 0:12:09the mothers have to make.
0:12:09 > 0:12:11It's a real dilemma.
0:12:13 > 0:12:15On the one hand, she needs to get going.
0:12:15 > 0:12:18There's no food for her in the warm water here
0:12:18 > 0:12:21and she hasn't fed properly for five months.
0:12:23 > 0:12:25On the other hand, if she leaves before her calf
0:12:25 > 0:12:29is strong enough to make the journey, it will probably die.
0:12:42 > 0:12:45At least I've some idea of what's ahead of me
0:12:45 > 0:12:49over the next few weeks on my journey.
0:12:49 > 0:12:53I just wonder whether the calves are really ready
0:12:53 > 0:12:55for what lies ahead of them.
0:13:09 > 0:13:11Before they set off,
0:13:11 > 0:13:15we've still got to identify those two special mums to follow.
0:13:15 > 0:13:19And Bruce reckons he's found them.
0:13:19 > 0:13:24The first one is called Shark Bite.
0:13:24 > 0:13:27Now she had an encounter with a great white shark
0:13:27 > 0:13:30that left her with some very distinguishing
0:13:30 > 0:13:34scars across her back, so we should be able to see her
0:13:34 > 0:13:36from quite a distance away.
0:13:36 > 0:13:40Now our second whale is going to be called Patch.
0:13:40 > 0:13:45And she has a perfectly round white patch on her back -
0:13:45 > 0:13:47about the size of a dinner plate.
0:13:47 > 0:13:49Shark Bite and Patch are on the starting blocks,
0:13:49 > 0:13:52but they haven't moved far from where they were first tagged
0:13:53 > 0:13:56in the lagoons down in Baja. They're still hanging about.
0:13:56 > 0:13:59But they'll have to begin their journey before long
0:13:59 > 0:14:01and head out with their calves into the open ocean.
0:14:07 > 0:14:10This is going to be a risky project.
0:14:10 > 0:14:14Tracking whales is no easy task.
0:14:14 > 0:14:17First of all, the signal from the whales' transmitters
0:14:17 > 0:14:18won't go through water.
0:14:18 > 0:14:22But the whales spend about 95% of their time under the water
0:14:22 > 0:14:24and that means the signal can
0:14:24 > 0:14:29only be picked up by the satellite when the whale comes up to breathe.
0:14:30 > 0:14:35Then if it's choppy, even a small wave breaking over a whale's back
0:14:35 > 0:14:37may block the signal.
0:14:37 > 0:14:40It's all a bit edgy.
0:14:49 > 0:14:53From Bruce's experience, it's best to get ahead of the whales
0:14:53 > 0:14:56and then wait for them to pass by.
0:14:56 > 0:14:58So it's time for me to head north too.
0:15:02 > 0:15:05The challenge is really ahead of us,
0:15:05 > 0:15:08which exactly mirrors that of the whales.
0:15:08 > 0:15:11Once they've left the safety of the lagoons,
0:15:11 > 0:15:14that's when things are going to get really sticky for them.
0:15:22 > 0:15:27Today, we head to Tijuana, and then up the west coast.
0:15:36 > 0:15:40So how on earth do the whales find their way?
0:15:42 > 0:15:46Well, for a start grey whales hug the coastline on their migration,
0:15:46 > 0:15:50which is really important for us trying to find them.
0:15:54 > 0:15:57Staying so close to shore probably helps the whales to navigate.
0:15:57 > 0:16:00You just keep the breaking surf on your right hand side
0:16:00 > 0:16:04and they may remember the changing taste of different rivers,
0:16:04 > 0:16:07which flow into the ocean along their route.
0:16:12 > 0:16:16Swimming near the shore may help with navigation,
0:16:16 > 0:16:18but it can be dangerous,
0:16:18 > 0:16:20even fatal.
0:16:27 > 0:16:31Fishermen's gill nets are an ever present threat in coastal waters.
0:16:31 > 0:16:33Whales need to breathe air
0:16:33 > 0:16:37and if they get tangled up below the surface - they'll drown.
0:16:48 > 0:16:50The decaying body acts as a magnet
0:16:50 > 0:16:54for the largest predatory fish in the ocean.
0:16:54 > 0:16:56The great white.
0:17:04 > 0:17:07They're not just scavengers -
0:17:07 > 0:17:12great whites are opportunists and may target calves.
0:17:35 > 0:17:39Soon the whales will be leaving Mexican waters
0:17:39 > 0:17:41and moving on up into California.
0:17:46 > 0:17:50Fortunately the whales have got diplomatic immunity, so they can
0:17:50 > 0:17:54just cruise across the border between Mexico and the US.
0:17:54 > 0:17:58Unfortunately, we don't have such privileges,
0:17:58 > 0:18:01so we have to wade through all of this.
0:18:08 > 0:18:10San Diego.
0:18:10 > 0:18:13We're definitely in the United States of America now.
0:18:13 > 0:18:18Look at that development. There isn't a part of that coastline that hasn't got a building on it.
0:18:18 > 0:18:23There's so much traffic here, there's so much noise.
0:18:23 > 0:18:26Who knows what the whales think when they reach this spot.
0:18:43 > 0:18:48This is our whales' first major contact with the world of man
0:18:48 > 0:18:51since leaving the lagoons and it's a rude awakening.
0:18:59 > 0:19:01Boy, are we a noisy bunch!
0:19:03 > 0:19:05ENGINE DRONES
0:19:09 > 0:19:13Like other whales, sound is a key sense for the greys
0:19:13 > 0:19:16and all this din must be very confusing,
0:19:16 > 0:19:18even dangerous.
0:19:18 > 0:19:22Calves could get separated from their mothers by boat traffic,
0:19:22 > 0:19:24so more experienced mums
0:19:24 > 0:19:28may guide their calves offshore, away from the noise of the city.
0:19:56 > 0:20:01I've been travelling up the coast of California for about 500 miles now.
0:20:01 > 0:20:03Time to check in with Bruce
0:20:03 > 0:20:06and see where Shark Bite and Patch have got to.
0:20:11 > 0:20:13Hi Bruce, it's Steve Leonard here.
0:20:13 > 0:20:15- 'Steve, how are you?'- Not too bad.
0:20:15 > 0:20:17How are the whales getting on?
0:20:17 > 0:20:19'They're doing quite well actually.
0:20:19 > 0:20:22- 'One's all the way up into central Washington.- Oh, wow.
0:20:22 > 0:20:24'We've got only three whales that are south of you.
0:20:24 > 0:20:28'One of them is 830, which you may recall is one of the animals
0:20:28 > 0:20:30'we saw down in the lagoon together.
0:20:30 > 0:20:34'Now there are two whales actually that are still down in Baja.'
0:20:34 > 0:20:36- They still haven't left?- 'Indeed.'
0:20:36 > 0:20:38What about our Shark Bite and Patch?
0:20:38 > 0:20:41Do you have any news on them?
0:20:41 > 0:20:46'Two of the animals that we aren't hearing from now regularly are those two.'
0:20:46 > 0:20:49Right, is that likely to be that they've shed the transmitters, or?
0:20:49 > 0:20:51'That's the most likely thing.
0:20:51 > 0:20:55'A little tag like this that weighs less than a third of a pound,
0:20:55 > 0:20:58- 'I mean, they pull out pretty easily.'- Yeah.
0:21:08 > 0:21:14I am very disappointed that Shark Bite and Patch
0:21:14 > 0:21:19have both gone off radar. Their transmitters...
0:21:19 > 0:21:25stopping working has been a real blow to us
0:21:25 > 0:21:29because we'd have loved to have known how they got on.
0:21:33 > 0:21:36It has not been heard from for two days.
0:21:36 > 0:21:40'I need to discuss our options with our production team.
0:21:40 > 0:21:45'We are working at the front line of science, so I guess we're bound to get some setbacks.'
0:21:45 > 0:21:49OK, that's fine. So, where do we stand for the next couple of days?
0:21:49 > 0:21:54'It could be that Shark Bite and Patch's transmitters are faulty and they'll come back online.'
0:21:54 > 0:21:58- He doesn't know whether she's online still.- Right, OK.- He'll try...
0:21:58 > 0:22:01'Looking on the bright side, there are hundreds
0:22:01 > 0:22:05'of mums and calves all travelling north up the coast.
0:22:05 > 0:22:10'and Bruce managed to tag 15 other mothers in Mexico for the project.
0:22:10 > 0:22:12'We're going to have to refocus.'
0:22:18 > 0:22:21One door closes, but another one opens.
0:22:21 > 0:22:25OK, so Shark Bite and Patch...
0:22:25 > 0:22:27off the map.
0:22:27 > 0:22:32But Bruce has told us that of the 15 other tagged whales that he's got,
0:22:32 > 0:22:38there is one that is definitely worth checking up on and she's got a bit of an interesting history.
0:22:38 > 0:22:43She's got a massive scar on her back.
0:22:43 > 0:22:46Now, we can't be absolutely sure,
0:22:46 > 0:22:51but it is most likely that this is from a harpoon.
0:22:51 > 0:22:54So she's quite distinctive and we're going to call her Scar,
0:22:54 > 0:22:56but actually her number is 830.
0:22:56 > 0:22:59The one thing that we do know about this new whale
0:22:59 > 0:23:03is that Bruce has seen her before and she's had a couple of calves already.
0:23:03 > 0:23:07She's no youngster - this is an experienced mum that's done this trip many times before.
0:23:07 > 0:23:11So we can only hope that she can do it again.
0:23:13 > 0:23:16From Bruce's latest data, Scar should be passing nearby.
0:23:16 > 0:23:22So early next morning over a snatched breakfast, I met up
0:23:22 > 0:23:27with Craig and Ladd, part of Bruce's team, to try and find her.
0:23:27 > 0:23:31The scientists are keen to find out not only how
0:23:31 > 0:23:36her calf is getting on, but why some transmitters appear to be failing.
0:23:37 > 0:23:41We need to find the highest point along the coast which will give us
0:23:41 > 0:23:45the best chance of picking up the signal from Scar's transmitter.
0:23:47 > 0:23:51But there's another problem.
0:23:51 > 0:23:55To save battery power and last the whole migration,
0:23:55 > 0:23:58the whales' transmitters are programmed to switch on
0:23:58 > 0:24:01for only one hour, four times each day.
0:24:03 > 0:24:07We've got a one hour period in which to catch this whale.
0:24:07 > 0:24:12The transmitter's going to be on for the next 45 minutes now.
0:24:12 > 0:24:16If we don't get it now, it's going to be this afternoon,
0:24:16 > 0:24:19but it's going to have swum further up the coast.
0:24:23 > 0:24:26We think we've found the perfect spot.
0:24:26 > 0:24:29And this is the piece of kit that will help us find our whale,
0:24:29 > 0:24:32which will bleep if it picks up Scar's signal.
0:24:37 > 0:24:38After half an hour of listening...
0:24:38 > 0:24:41absolutely nothing.
0:24:44 > 0:24:46Our time is fast running out.
0:24:46 > 0:24:50I really thought that Scar was going to do it for us.
0:24:50 > 0:24:53Is her transmitter still on? Is she still alive? We don't know.
0:24:53 > 0:24:57We can only just sit out and wait and hope that by the time
0:24:57 > 0:25:01the next transmitter cycle comes on she bings back onto the screen.
0:25:04 > 0:25:07Everyone's starting to get just a bit worried.
0:25:07 > 0:25:09We should be doing better than this.
0:25:09 > 0:25:12But of course, the whales have no idea there's a whole lot of us
0:25:12 > 0:25:15running about after them scratching our heads.
0:25:15 > 0:25:20They're just powering on, unstoppably piling on the miles
0:25:20 > 0:25:24at a steady three miles an hour, both day and night.
0:25:24 > 0:25:28So we just have to keep travelling north.
0:25:41 > 0:25:44Although the calf is growing quickly and getting stronger,
0:25:44 > 0:25:49it's still completely dependent on its mother for food and guidance.
0:25:49 > 0:25:53The baby saves energy by swimming in the slipstream of its mum
0:25:53 > 0:25:57and she'll keep her calf to the shoreward side for protection.
0:26:03 > 0:26:08The whales have been travelling non-stop now for about two weeks
0:26:08 > 0:26:10and have swum around 900 miles.
0:26:10 > 0:26:14So far it's been pretty much plain sailing for most of them,
0:26:14 > 0:26:18but all that's just about to change.
0:26:18 > 0:26:22The whales are approaching an area of maximum danger.
0:26:22 > 0:26:25Not all of them will escape with their lives.
0:26:25 > 0:26:29This vast chasm is the largest underwater canyon on the west coast
0:26:29 > 0:26:34of North America, plunging down over 6,000 feet.
0:26:34 > 0:26:40Down in the shadows lurks one of the ocean's top predators.
0:26:40 > 0:26:42They know the whales are coming
0:26:42 > 0:26:46and every year they gather here and wait.
0:26:47 > 0:26:50Every grey whale mother that migrates up this coast
0:26:50 > 0:26:52will eventually find herself here.
0:26:52 > 0:26:55This is Monterey Bay.
0:26:55 > 0:26:59And out there is the biggest threat that our grey whales
0:26:59 > 0:27:01are going to face in their entire journey.
0:27:01 > 0:27:03Here they have a choice.
0:27:03 > 0:27:07Either they dart across the mouth as fast as they can,
0:27:07 > 0:27:12or they try and sneak around the coastline as quietly as possible
0:27:12 > 0:27:14in the hope that they'll avoid detection.
0:27:14 > 0:27:16If they get it wrong,
0:27:16 > 0:27:20it could mean the death of their calves or even themselves.
0:27:20 > 0:27:23So do you run,
0:27:23 > 0:27:24or do you hide?
0:27:28 > 0:27:34But what could possibly threaten an enormous 35 ton whale?
0:27:36 > 0:27:37These could.
0:27:39 > 0:27:42A fraction of the size of a grey whale,
0:27:42 > 0:27:45but killer whales hunt in packs
0:27:45 > 0:27:47and they're a proper carnivore.
0:27:55 > 0:28:00These are the only predators the whales really have to fear.
0:28:00 > 0:28:04Killer whales will often pursue mothers and calves for hours,
0:28:04 > 0:28:06until they're exhausted.
0:28:15 > 0:28:17But by taking the long way round,
0:28:17 > 0:28:21our mothers and calves can hide in a vast underwater forest.
0:28:33 > 0:28:35The water here is thick with kelp,
0:28:35 > 0:28:38which grows in the shallows around the edge of the bay,
0:28:38 > 0:28:40a place that the killer whales will not venture.
0:28:44 > 0:28:49So by travelling through the kelp, mothers and calves can avoid attack.
0:28:53 > 0:28:55That is incredible!
0:28:55 > 0:28:58It doesn't look like much from the surface,
0:28:58 > 0:29:01but when you get underneath there - it's huge.
0:29:01 > 0:29:03It goes right down to the bottom -
0:29:03 > 0:29:07that's about 30 feet and you can understand
0:29:07 > 0:29:11how even a mammal as big as a whale could hide in amongst this stuff.
0:29:17 > 0:29:22Older, more experienced mums, like Scar, will know this
0:29:22 > 0:29:24and when she gets here she'll hide herself
0:29:24 > 0:29:27and her calf away in the kelp forest.
0:29:27 > 0:29:30Less experienced mothers may take the short cut,
0:29:30 > 0:29:33with possibly fatal consequences.
0:29:36 > 0:29:40The danger to the whales that try to dart across the mouth of the bay
0:29:40 > 0:29:44was vividly brought home to me when one of our cameramen,
0:29:44 > 0:29:47who's based here, was out in the Bay filming from his boat
0:29:47 > 0:29:49just the day before we arrived.
0:29:49 > 0:29:55Florian Graner witnessed a ferocious attack at very close quarters!
0:29:55 > 0:30:00- So what happened?- Well, basically we took the boat out from Monterey Harbour yesterday
0:30:00 > 0:30:02and we met a group of whale watchers out there
0:30:02 > 0:30:07and they had a large pod of killer whales, probably around 30.
0:30:07 > 0:30:10We saw all the whales speeding up, they were leaping
0:30:10 > 0:30:11all over the place,
0:30:11 > 0:30:14we saw them flying through the air, big rooster tails
0:30:14 > 0:30:19and we saw they were homing in onto a grey whale, a female with a calf.
0:30:19 > 0:30:22And they were just pounding on those grey whales
0:30:22 > 0:30:26and she was really protective, but she'd got so many whales on her
0:30:26 > 0:30:29she was just with the fluke up through the air.
0:30:29 > 0:30:33They were just all streaming in from all sides.
0:30:39 > 0:30:42So, all those killer whales were just picking up speed
0:30:42 > 0:30:43and leaping all over the place.
0:30:43 > 0:30:45It was so intense, it was a feast.
0:31:03 > 0:31:06- Who was on the boat?- Well, it was my wife, my two-and-a-half year old
0:31:06 > 0:31:10and a neighbour who was out with me for the first time.
0:31:12 > 0:31:15And what happened then is the grey whale, all of a sudden,
0:31:15 > 0:31:19came across and homed into the boat and went under the boat.
0:31:19 > 0:31:21'She's coming under the boat.'
0:31:21 > 0:31:23She was diving for cover.
0:31:23 > 0:31:26Course, she's longer than the boat, she's a fully grown female,
0:31:26 > 0:31:28so she's about 13, 14 metres.
0:31:31 > 0:31:32'Hold on to Jasmine!'
0:31:32 > 0:31:36Then she started freaking
0:31:36 > 0:31:39and she hit against the boat and we saw the tail fluke
0:31:39 > 0:31:42come around here and it ripped up the entire swim step.
0:31:42 > 0:31:44It's all gone, it's just way up in the air.
0:31:44 > 0:31:48I was up there filming it and I saw the swim step flying right past me
0:31:48 > 0:31:53up in the air and the wind picked it up and it went way off.
0:31:53 > 0:31:56I caught myself just here, I had my camera up, whoa, up in the air,
0:31:56 > 0:31:58I was almost about to fall over.
0:31:58 > 0:32:01And she then gave us a real blow from the side,
0:32:01 > 0:32:04she ripped off the entire out-drive - this bit here.
0:32:04 > 0:32:06It's all snapped off, we lost our power.
0:32:06 > 0:32:08I had to call the coastguard to get back in.
0:32:08 > 0:32:12And the grey whale didn't leave, she still tried to hide
0:32:12 > 0:32:16- under the boat, and the killer whales were still biting, with her calf.- Did the calf survive?
0:32:16 > 0:32:18I don't think so, I already saw blood
0:32:18 > 0:32:24coming out of the mouth of the calf and by that time, we had about 30 killer whales coming in.
0:32:37 > 0:32:39'She's coming underneath the boat.
0:32:39 > 0:32:41'Hold on to Jasmine.'
0:32:51 > 0:32:55For that mother, all the nurturing and investment in her calf
0:32:55 > 0:33:00has come to nothing and she'll continue the migration on her own.
0:33:00 > 0:33:04She won't have another calf for at least two years.
0:33:04 > 0:33:09No-one knows how many whales are killed here on the migration,
0:33:09 > 0:33:13but eye witness reports suggest at least a dozen attacks every year.
0:33:17 > 0:33:22After all that blood and carnage, it's so lovely to be reminded
0:33:22 > 0:33:24that most of the whales actually make it past.
0:33:24 > 0:33:28And these mothers don't even seem to be in that big a hurry.
0:33:28 > 0:33:30There's still time for playing
0:33:30 > 0:33:34and bonding and just rolling around here.
0:33:44 > 0:33:48I've been in touch with Bruce and happily Scar is still on the move.
0:33:48 > 0:33:50She's cleared the danger zone.
0:33:54 > 0:33:58The mother's urge to keep driving north is overwhelming.
0:33:58 > 0:34:02Our whales will soon pass San Francisco.
0:34:05 > 0:34:08They may be travelling relatively slowly,
0:34:08 > 0:34:10but grey whales just don't stop.
0:34:10 > 0:34:13I need to crack on and get ahead.
0:34:18 > 0:34:21The best chance we have of finding tagged whales
0:34:21 > 0:34:24is now well north of here at Newport, on the coast of Oregon,
0:34:24 > 0:34:28which happens to be where Bruce and his team are based.
0:34:50 > 0:34:53At this time of year along this entire stretch of coast,
0:34:53 > 0:34:56you don't have to stare out to sea for long
0:34:56 > 0:35:00to see grey whales out there plodding inexorably along
0:35:00 > 0:35:03on this mammoth journey.
0:35:06 > 0:35:08But we want to see our tagged whales
0:35:08 > 0:35:12and know how they and their calves are getting along.
0:35:12 > 0:35:14It just seems that the technology
0:35:14 > 0:35:17isn't quite giving us the answers we need.
0:35:21 > 0:35:26So next morning, I arranged to see Bruce at Oregon State University
0:35:26 > 0:35:31where he's based to find out why he thinks so many of the tags have gone down.
0:35:31 > 0:35:35You remember in the lagoon how the whales were sliding down mum,
0:35:35 > 0:35:38lounging over her blowhole and back and forth?
0:35:38 > 0:35:41Well, that kind of stuff is really hard. This tag weighs
0:35:41 > 0:35:48only 150 grams and so when it comes to a one-ton calf moving about, it's easy to pull out.
0:35:48 > 0:35:52That's something that's kind of gratifying for us to know, that if an animal
0:35:52 > 0:35:58gets entangled in something this is not gonna be a means of debilitating the animal, that this will let go.
0:35:58 > 0:36:01And is this what you'd expected at the start?
0:36:01 > 0:36:05Because this has never been done before and I, I tend to be an optimist,
0:36:05 > 0:36:10I thought it was gonna be a little easier actually than what it's turned out to be.
0:36:10 > 0:36:14Course we're dealing with animals that are underwater more than 95% of the time
0:36:14 > 0:36:17and that's difficult just to see them.
0:36:17 > 0:36:22But finding the ports and the proximity and good weather and daylight
0:36:22 > 0:36:28are compound probabilities that have had us having fewer opportunities to resight animals than I'd hoped.
0:36:28 > 0:36:34But right now, 830 is off Vancouver Island, off British Columbia.
0:36:34 > 0:36:38So making good progress and it will be really exciting to see
0:36:38 > 0:36:42that get up hopefully on into the Bering Sea for the feeding season.
0:36:44 > 0:36:47It's important for the scientists to go out
0:36:47 > 0:36:50and physically find the tagged whales.
0:36:51 > 0:36:55After all, it's the only way they can tell if the calf is still alive.
0:37:01 > 0:37:05So far, making contact with an individual whale
0:37:05 > 0:37:08has proved to be very difficult.
0:37:08 > 0:37:09Scar is now out of reach,
0:37:09 > 0:37:15but the data shows another tagged whale, number 839, is nearby.
0:37:15 > 0:37:19So it's a great opportunity to go out and try and find her
0:37:19 > 0:37:21and check on her calf.
0:37:21 > 0:37:27Bruce has mustered the entire team and pulled out all the stops.
0:37:27 > 0:37:29He's up spotting from a plane.
0:37:31 > 0:37:33We've got people spotting from the cliffs
0:37:33 > 0:37:36and there's a second boat too,
0:37:36 > 0:37:39giving us our best chance of locating a tagged whale.
0:37:45 > 0:37:48There are three whales up ahead.
0:37:52 > 0:37:55Who knows, one might be ours!
0:37:57 > 0:38:00- Did you get a good look at it, Ladd? - Yeah, I didn't see anything.
0:38:00 > 0:38:04They've got four more up where they are circling over there,
0:38:04 > 0:38:06so I think we should head over there.
0:38:06 > 0:38:10There are plenty of whales passing by, but the team need to check out
0:38:10 > 0:38:12each one to see if it's got a tag.
0:38:12 > 0:38:13There they go.
0:38:17 > 0:38:21That's about the seventh whale we've been able to get up and close to,
0:38:21 > 0:38:24so there's lots and lots of mothers here.
0:38:24 > 0:38:28And they all seem to have calves, so far. I haven't seen any single mums.
0:38:28 > 0:38:32- We got a pretty good look at that mum, right?- Yeah.
0:38:32 > 0:38:35Our tagged whale has to be here somewhere.
0:38:37 > 0:38:40No tag, no tag, no tag...
0:38:48 > 0:38:52If any of you are sitting at home and thinking, "I know,
0:38:52 > 0:38:56"I'll pop along to the coast and follow a whale on its migration,"
0:38:56 > 0:39:01a word of warning. It is very, very difficult.
0:39:01 > 0:39:05In fact, this is possibly one of the hardest things I've ever had to do.
0:39:05 > 0:39:09Even with Bruce up in his plane, two boats on the water,
0:39:09 > 0:39:12somebody up on a cliff with a directional receiver,
0:39:12 > 0:39:18we should have been right on top of that whale today, but we never saw her...
0:39:18 > 0:39:20or so we thought.
0:39:22 > 0:39:25I have in my hand a piece of paper.
0:39:25 > 0:39:28Craig was taking photographs all day at the front of the boat
0:39:28 > 0:39:30of any whale that popped up.
0:39:30 > 0:39:33And this is one of his photographs.
0:39:33 > 0:39:35This is 839!
0:39:35 > 0:39:37And how do we know that?
0:39:37 > 0:39:39This little yellow tag here.
0:39:39 > 0:39:44It was the whale we were expecting to find and this confirms it.
0:39:44 > 0:39:48And what's more, we know from Craig's notes that when we saw
0:39:48 > 0:39:54this whale, there was a healthy calf swimming right alongside her, which is the best news of all.
0:40:08 > 0:40:13Calves rely on mothers' milk for the first eight months of their lives.
0:40:13 > 0:40:18But they need around 230 litres every single day.
0:40:18 > 0:40:20To meet this huge demand,
0:40:20 > 0:40:24mothers like Scar need to convert their fat reserves to milk.
0:40:26 > 0:40:29On this migration she could lose ten tons,
0:40:29 > 0:40:32that's one third of her body weight.
0:40:36 > 0:40:41It's Mother's Day here in the States and I was thinking about it last night, mothers.
0:40:41 > 0:40:44Mammals do make the best mothers.
0:40:44 > 0:40:49They invest so much time and energy into one offspring. They're not like,
0:40:49 > 0:40:54you know, reptiles or some of the invertebrates that dump thousands
0:40:54 > 0:40:57of eggs into the sea in the hope that one will survive.
0:40:57 > 0:41:02They really do invest all their time and energy into that one baby.
0:41:02 > 0:41:04And our grey whale mothers,
0:41:04 > 0:41:11you know, they deserve some sort of medal because not only do they carry them all the way down from Alaska
0:41:11 > 0:41:15inside them and then give birth in these beautiful sort of nursery lagoons,
0:41:15 > 0:41:21but then they move up the coast until they can fend and start to feed for themselves.
0:41:21 > 0:41:23But I think my mum's just as special
0:41:23 > 0:41:26and I thought I'd send my mother a text.
0:41:32 > 0:41:36We've had no information from Scar for a few days and I was beginning
0:41:36 > 0:41:40to think things were turning against us again and we might have lost her.
0:41:40 > 0:41:44But then I got a message to call Bruce.
0:41:44 > 0:41:47- 'Hello, Bruce Mate.' - Hi Bruce, it's Steve Leonard here.
0:41:47 > 0:41:50- 'Hi, Steve. How are you?' - Yeah, great, good.
0:41:50 > 0:41:53Now, what's the situation with the whales?
0:41:53 > 0:41:57- 'We're doing well, I think. Over the last five days we've heard from six animals.'- Oh, OK.
0:41:57 > 0:42:02'But given that we've heard in the last three days from one that's been
0:42:02 > 0:42:06'off for five, one that's been off for six and one that's been off for seven,
0:42:06 > 0:42:10'it's really kind of hard to say. Only time will tell, how many animals we still have active.'
0:42:10 > 0:42:14I got your message, yeah, yesterday about 830.
0:42:14 > 0:42:17'Yes, it looks like it's settling down at the north end
0:42:17 > 0:42:20'of the island, it arrived at yesterday.
0:42:20 > 0:42:24'The last three locations are within six miles, about 60 miles west of
0:42:24 > 0:42:27'Prince Rupert and she's right at the tip of what looks
0:42:27 > 0:42:30'to be almost a harbour like situation there.'
0:42:30 > 0:42:31'That's great news.
0:42:31 > 0:42:34'Scar's still going strong.
0:42:34 > 0:42:36'But now, there's a mystery.
0:42:36 > 0:42:39'After travelling non-stop for nearly six weeks,
0:42:39 > 0:42:40'Scar has suddenly stopped.
0:42:40 > 0:42:45'For some reason she's broken her journey.
0:42:45 > 0:42:49'Why? What's so special about this particular place?
0:42:50 > 0:42:52'Well, there's only one way to find out.
0:42:53 > 0:42:57'The crew and I will just have to go there and investigate.'
0:43:01 > 0:43:06From Mexico, up the USA and now into Canada.
0:43:08 > 0:43:12By the time they pass Vancouver Island, mothers and babies
0:43:12 > 0:43:16have swum non-stop for about 2,500 miles
0:43:16 > 0:43:19and are not quite halfway.
0:43:24 > 0:43:29They still have the equivalent of New York to London to go,
0:43:29 > 0:43:32just 3,500 miles left.
0:43:37 > 0:43:41It's taken a bit of time, but we're here - Canada.
0:43:41 > 0:43:43This is where our whales are.
0:43:43 > 0:43:46And I am sick to death of very small boats,
0:43:46 > 0:43:49so we've got ourselves a proper boat.
0:43:50 > 0:43:54We're on the south side of Vancouver Island at the moment
0:43:54 > 0:43:57and we've got to motor for at least a day and a half
0:43:57 > 0:43:59to get to where the whales were.
0:43:59 > 0:44:01So I'd better get on board.
0:44:01 > 0:44:03Steady as she goes.
0:44:36 > 0:44:39I love the sound of the sea.
0:44:39 > 0:44:43It's possibly the most relaxing sound I can think of.
0:44:43 > 0:44:47It's amazing to think that there are grey whales out there not sleeping at the moment.
0:44:47 > 0:44:51Because marine mammals, most of them, are conscious breathers,
0:44:51 > 0:44:54that means they have to stay awake to breathe.
0:44:54 > 0:45:00So if you look at their nostrils, you can see that the relaxed state is shut,
0:45:00 > 0:45:03which makes sense if you spend most of your time under the water
0:45:03 > 0:45:08and it actually takes muscular effort to pull them open and hold them open to actually breathe.
0:45:08 > 0:45:12We do know for sure that they don't nod off in the same way that we do,
0:45:12 > 0:45:20which is pretty unlucky for them because they don't know what they're missing. Sleep's great!
0:45:23 > 0:45:27Next morning, we finally arrive just north of Vancouver Island
0:45:27 > 0:45:30at the exact co-ordinates where Scar stayed for six days.
0:45:35 > 0:45:37She's now moved on.
0:45:37 > 0:45:42But why after all her hard work to get this far did she just stop?
0:45:42 > 0:45:45There's got to be something special about these waters.
0:45:50 > 0:45:52The answer's immediately clear.
0:45:52 > 0:45:54The sea is like pea soup -
0:45:54 > 0:45:59it's rammed with tiny shrimp-like creatures, they're called mysids.
0:45:59 > 0:46:02It's so thick I can hardly see my dive buddy.
0:46:05 > 0:46:08These swarms of mysids are the reason she stayed.
0:46:08 > 0:46:13For the first time in months, Scar could find something to eat.
0:46:13 > 0:46:15Just look how thick that is.
0:46:17 > 0:46:18That is amazing.
0:46:22 > 0:46:25Who'd think that a huge animal like a grey whale
0:46:25 > 0:46:29could live off such tiny, tiny creatures?
0:46:29 > 0:46:32And then imagine a grey whale comes swooping by
0:46:32 > 0:46:34and wallop, they're all gone.
0:46:34 > 0:46:38It's only when you see them like this that you really get
0:46:38 > 0:46:42an understanding of how a whale can feed off these things.
0:46:44 > 0:46:46Condense this down into one mouthful -
0:46:46 > 0:46:49it's actually quite a bit of food.
0:46:56 > 0:47:00I've brought some of the mysids back to the surface for a better look.
0:47:00 > 0:47:03Every mouthful of these creatures is important for the mothers
0:47:03 > 0:47:07because they still have a very long way to go.
0:47:10 > 0:47:14We keep saying they haven't eaten anything for over five months
0:47:14 > 0:47:20and it kind of loses sense after a while. And then you really think about it
0:47:20 > 0:47:24and it's that, "What must that first mouthful be like?"
0:47:24 > 0:47:28OK, they might have grabbed little snacks here and there,
0:47:28 > 0:47:32but that first big swarm that they hit and they just zoom in
0:47:32 > 0:47:35and just spend the entire day just hoovering these things up.
0:47:35 > 0:47:40What that must feel like... you know, the rush of glucose
0:47:40 > 0:47:43through their system, the rush of energy they must get
0:47:43 > 0:47:45out of that must be so intense.
0:47:45 > 0:47:47It's not a proper feed for Scar,
0:47:47 > 0:47:50it's more like a snack, but it's the first place
0:47:50 > 0:47:54since she left Mexico that she's had anything to help keep her going.
0:47:54 > 0:47:59And by now the mums are running out of fuel on this immense journey.
0:48:01 > 0:48:04All the way up, the mothers will be teaching their calves the route
0:48:04 > 0:48:06and it's information like this -
0:48:06 > 0:48:10where to find food on the way, that they really need to know.
0:48:10 > 0:48:13These things are crucial for the calf to remember
0:48:13 > 0:48:18because the next time it makes this journey, it will be all alone.
0:48:18 > 0:48:23- PHONE RINGS - Time to check in with Bruce again.
0:48:23 > 0:48:26- Hi Bruce,- 'Hi Steve, how are you?'
0:48:26 > 0:48:28Not too bad, not too bad at all.
0:48:28 > 0:48:34- 'Good, I've just logged on and got information from six of our whales today.'- Oh, wow!
0:48:34 > 0:48:38'There's one that's just turned the corner at Unimak Pass,
0:48:38 > 0:48:42'and there's one all the way over south west of the Gulf of Anadyr,
0:48:42 > 0:48:44'along the Russian coast.
0:48:44 > 0:48:47'There's one that's just gone through the Bering Straits
0:48:47 > 0:48:50'and is now in the high Arctic basically.
0:48:50 > 0:48:53- 'Wow, that far north?- Yeah.
0:48:53 > 0:48:55'And what about Scar, 830?
0:48:55 > 0:48:57'Has she made it to the Arctic?
0:48:57 > 0:49:01'Um, that animal is on the east side of Bering Strait.
0:49:01 > 0:49:04- 'This is really exciting.- Yeah, you must be over the moon.
0:49:04 > 0:49:06'That is absolutely fantastic.
0:49:06 > 0:49:11'Well, I am. Nobody's ever seen this kind of information about how whales move about.'
0:49:11 > 0:49:13Incredible. I wonder how their calves are doing?
0:49:13 > 0:49:17'I do too. Wouldn't that be wonderful, to be able to drop in on
0:49:17 > 0:49:21'them and know that their calves were still safe and sound and doing well?
0:49:21 > 0:49:25'Let me know if I can help. I'd be delighted to have you spot some of these whales.'
0:49:25 > 0:49:29- Yeah, now that's awesome. - 'All right.'- Bye!
0:49:29 > 0:49:33It seems that there's just been a flush of data in the last week or so
0:49:33 > 0:49:35and the whales have been going great guns.
0:49:37 > 0:49:40No wonder Bruce is pleased.
0:49:40 > 0:49:43For a while, I thought none of our tags would make the distance.
0:49:43 > 0:49:46But we've got loads of whales online
0:49:46 > 0:49:50and the best news for us is that Scar is amongst them.
0:49:50 > 0:49:54But now we're heading into unknown scientific territory.
0:49:54 > 0:49:57No-one realised they roamed so widely.
0:49:57 > 0:50:01That means we've got to completely change all our plans again
0:50:01 > 0:50:05if we've got any chance of catching up with Scar and hopefully her calf.
0:50:05 > 0:50:08Just seeing if I've got Alaska Airlines number.
0:50:08 > 0:50:13Those are on Alaskan and they have availability for five people?
0:50:19 > 0:50:21At last we can search for an answer to the question.
0:50:21 > 0:50:26Why on earth do the whales travel all the way up to the Arctic?
0:50:29 > 0:50:32We've come to Nome in Alaska.
0:50:41 > 0:50:45Now we've got settled into the hotel, it's time to check out the sights of Nome
0:50:45 > 0:50:47before we run out of sunlight.
0:50:47 > 0:50:51Actually, we're not going to run out of sunlight.
0:50:51 > 0:50:58It's just gone past midnight and the sun is still well above the horizon.
0:50:58 > 0:51:01Because there's no night up here in the summer,
0:51:01 > 0:51:05everything's growing and feeding flat out, the whole 24 hours.
0:51:05 > 0:51:08It's an explosion of productivity.
0:51:11 > 0:51:16It's not just 24 hour daylight that makes this an ideal
0:51:16 > 0:51:20feeding ground for the grey whales - it's also the water temperature.
0:51:20 > 0:51:22It's absolutely freezing.
0:51:22 > 0:51:25Cold water holds a lot more oxygen than warm water,
0:51:25 > 0:51:29making the Bering Sea some of the most productive waters on the planet.
0:51:29 > 0:51:33There are over 450 species of fish out there.
0:51:34 > 0:51:37And tons and tons of grey whale food
0:51:37 > 0:51:40because this is what the migration is all about.
0:51:40 > 0:51:44After travelling non-stop for nearly three months and swimming
0:51:44 > 0:51:49over 6,000 miles, the whales can finally get a square meal.
0:51:49 > 0:51:52They'll spend the next four months
0:51:52 > 0:51:55of the Arctic summer here, just feasting.
0:52:06 > 0:52:09Grey whales have a very unusual way of feeding.
0:52:09 > 0:52:14Their food, millions of little crustaceans is buried in the seabed,
0:52:14 > 0:52:18so to get at it they scoop up huge mouthfuls of mud.
0:52:18 > 0:52:22Then they squeeze the sediment through fine filters in their mouth
0:52:22 > 0:52:24to sift out the tiny creatures.
0:52:26 > 0:52:29No other whale feeds like this.
0:52:37 > 0:52:42An adult will swallow around 130 tons of food over the summer.
0:52:46 > 0:52:49At last, they can start to replace all the weight they've lost
0:52:49 > 0:52:51on the long trip north.
0:52:54 > 0:52:57It's easy to spot feeding grey whales
0:52:57 > 0:53:00by the gigantic plumes of mud they leave behind.
0:53:14 > 0:53:18No-one had any idea the whales would range so far
0:53:18 > 0:53:22during their feeding season, but fortunately Scar's latest position
0:53:22 > 0:53:24is still within air range of Nome
0:53:24 > 0:53:31and we're going to set out in one of her transmission periods to try and find her.
0:53:34 > 0:53:37But, we only have that crucial one-hour time window,
0:53:37 > 0:53:42when her transmitter's switched on, to make contact with Scar.
0:53:53 > 0:53:55OK, this is it, moment of truth.
0:53:55 > 0:53:58We're right over where her last fix was.
0:54:02 > 0:54:05If we hear a beep, it could be our whale.
0:54:05 > 0:54:08Anything could happen in the next hour.
0:54:11 > 0:54:15We're just gonna slowly circle and hopefully we're gonna pick her up.
0:54:17 > 0:54:22Oh, wow, yes. Yeah, we've got one whale.
0:54:22 > 0:54:25- We've got two of 'em.- There's two, there's one feeding here.
0:54:25 > 0:54:26Oh, look at that!
0:54:26 > 0:54:30Yeah, the muddy blooms are from when it's feeding.
0:54:30 > 0:54:34Oh, that's great. Well, that's a good start. Oh, big fluke up.
0:54:34 > 0:54:35There goes the fluke.
0:54:35 > 0:54:39I can't believe it. I can't believe we've got whales feeding.
0:54:39 > 0:54:41We've come all this way.
0:54:43 > 0:54:46This is obviously just the right sort of sea bottom for them -
0:54:46 > 0:54:49it's shallow enough and it's obviously rich in food.
0:54:49 > 0:54:53Here's another one. 11 o'clock here, it will be coming down the left side.
0:54:53 > 0:54:55Oh, yes, yeah, yep.
0:54:55 > 0:54:57Come on, give us a beep.
0:54:57 > 0:54:59Nothing yet.
0:54:59 > 0:55:02There's another one right underneath us.
0:55:02 > 0:55:04I'll try and hook round, catch that one.
0:55:04 > 0:55:08We're about a half way through the period that the whales' transmitters
0:55:08 > 0:55:13are switched on now and so far nothing...no bleeps.
0:55:13 > 0:55:15Time's running out.
0:55:15 > 0:55:17There's a mother and calf.
0:55:17 > 0:55:20It's good to see some calves.
0:55:20 > 0:55:25We've been seeing a lot of whales and not many calves, but now we've just come across a few.
0:55:25 > 0:55:27Three of them all in a row here again.
0:55:27 > 0:55:29Yeah.
0:55:29 > 0:55:33Well, we've got about ten minutes left to go
0:55:33 > 0:55:36and we haven't heard a peep from 830, but we have seen
0:55:36 > 0:55:40so many whales - this place is absolutely hoaching with them
0:55:40 > 0:55:42at the moment and they're all feeding.
0:55:42 > 0:55:45And that's all they're gonna be doing
0:55:45 > 0:55:47until it's time to go south yet again.
0:55:47 > 0:55:51That, my friend, is two whales right next to each other.
0:55:51 > 0:55:53That's mother and calf, yeah.
0:55:53 > 0:56:00We've got two whales beneath us - one of them's definitely a calf.
0:56:00 > 0:56:04Unfortunately, we're outside of our transmission time.
0:56:04 > 0:56:08That one has got a big marking on its back.
0:56:08 > 0:56:13There's a massive marking on its back. That could be Scar.
0:56:13 > 0:56:16Well, here is a mother and calf finally.
0:56:18 > 0:56:20It would be nice to think it was Scar.
0:56:24 > 0:56:26- There's something on her back.- Yeah.
0:56:26 > 0:56:29There's definitely something.
0:56:29 > 0:56:31That could be Scar's scar.
0:56:34 > 0:56:39Well, we've got a mother and calf, it's not definitely Scar.
0:56:39 > 0:56:43I'd like to think it is, but we're outside of the transmission period,
0:56:43 > 0:56:46so we can't definitely say it is, but it's incredible.
0:56:46 > 0:56:50That calf has swum 6,000 miles to get here.
0:56:50 > 0:56:54Started when it was only a few months old,
0:56:54 > 0:56:57or maybe even a matter of weeks old.
0:56:57 > 0:57:00And it's made it all the way up here.
0:57:00 > 0:57:03That's a pretty heart-warming sight to see.
0:57:16 > 0:57:19The mother's work is almost done.
0:57:19 > 0:57:24By late October, winter will return and the sea will freeze over.
0:57:24 > 0:57:27All the whales must escape south
0:57:27 > 0:57:31and begin their voyage back to the breeding lagoons in Mexico.
0:57:33 > 0:57:37The young grey whales have had the best possible start in life,
0:57:37 > 0:57:40nurtured and protected by their mums
0:57:40 > 0:57:43every moment of their epic journey north.
0:57:44 > 0:57:48The calf has had just this one opportunity,
0:57:48 > 0:57:52this one shared journey to learn all it can from its mum.
0:57:52 > 0:57:57Soon Scar and her calf will part and go their separate ways.
0:58:00 > 0:58:05But, as with all the animals in Incredible Journeys,
0:58:05 > 0:58:09these whales are still writing their own story.
0:58:44 > 0:58:48Subtitles by Red Bee Media 2006
0:58:48 > 0:58:51E-mail subtitling@bbc.co.uk