0:00:02 > 0:00:07*
0:01:22 > 0:01:24Birds are masters of the air
0:01:24 > 0:01:28and can gather food from anywhere on the land.
0:01:28 > 0:01:31But most of the Earth is covered with water
0:01:31 > 0:01:36and so some birds became extremely competent there too - both in it
0:01:36 > 0:01:39and on it.
0:02:19 > 0:02:24These shallow, gravelly streams here in the New Zealand Alps
0:02:24 > 0:02:28seem desolate places devoid of any food.
0:02:28 > 0:02:32But look under this pebble I just picked up -
0:02:32 > 0:02:34 several succulent insect larvae.
0:02:34 > 0:02:42And in fact these streams, like waters fresh or salt all over the world, are full of food.
0:02:42 > 0:02:47With two-thirds of the world covered with water, that's a huge resource.
0:02:47 > 0:02:51No group of animals living OUT of water
0:02:51 > 0:02:59have developed a wider range of techniques, and indeed tools, for collecting that food, than the birds.
0:02:59 > 0:03:06This one is unique - the only beak in the entire bird world that is bent to one side.
0:03:06 > 0:03:12This is the wrybill, which only lives here in New Zealand.
0:03:15 > 0:03:21Its extraordinary beak enables it to probe beneath large, heavy boulders
0:03:21 > 0:03:25that it couldn't possibly turn over or even shift.
0:03:37 > 0:03:40And, just in case you're wondering,
0:03:40 > 0:03:43 the bend is always to the right.
0:03:47 > 0:03:51Dippers plunge right into the streams.
0:03:57 > 0:04:02This one is in Yellowstone, in the American West.
0:04:02 > 0:04:05Hot volcanic springs keep streams ice-free,
0:04:05 > 0:04:09so dippers can walk underwater throughout the year.
0:04:11 > 0:04:16Their dense, oily plumage retains air to such a degree
0:04:16 > 0:04:21that it forms a silvery cloak around their body and so keeps them warm.
0:04:31 > 0:04:35The disadvantage of that coat of air
0:04:35 > 0:04:39 is that it makes its wearer very buoyant,
0:04:39 > 0:04:44and a dipper has to struggle hard to remain below the surface.
0:04:56 > 0:05:03They seldom manage to stay underwater for much more than a quarter of a minute at a time.
0:05:23 > 0:05:29Kingfishers are only underwater for a second. They are living harpoons.
0:05:29 > 0:05:34This is one of the bigger members of the family, the belted kingfisher.
0:05:34 > 0:05:41The size of a small crow, it lives beside rivers and lakes all over North America.
0:05:41 > 0:05:46Understandably, it prefers places where the water is clear
0:05:46 > 0:05:49so it has a good view of its targets.
0:06:06 > 0:06:10It must now stun the fish, which has to be head outwards.
0:06:17 > 0:06:24But to swallow it without the spiny fins sticking in its throat, it must turn the fish round again.
0:06:37 > 0:06:43Most kingfishers dive from perches, so they are tied to the shore.
0:06:43 > 0:06:46Only one of them is able to break that link.
0:06:47 > 0:06:50This is the African pied kingfisher
0:06:50 > 0:06:55and it can launch its dive from high in the sky
0:06:55 > 0:06:59because, even in totally still air, it can hover.
0:06:59 > 0:07:04It's the biggest bird in the world to be able to do this.
0:07:22 > 0:07:26It's not only a diver - sometimes it's a juggler.
0:07:37 > 0:07:41The darter does ITS harpooning underwater.
0:07:41 > 0:07:46It's so at home there that it can creep up on its prey.
0:07:48 > 0:07:50Missed!
0:08:06 > 0:08:11IT always has to juggle to get its catch off its harpoon.
0:08:24 > 0:08:29The darter doesn't have the dipper's problem with buoyancy
0:08:29 > 0:08:32because its feathers actually absorb water.
0:08:33 > 0:08:37But that means that it gets soaked to the skin,
0:08:37 > 0:08:44and after a swim, like anyone in a wet bathing costume, it has to dry itself quickly and thoroughly
0:08:44 > 0:08:46if it's not to get a chill.
0:08:57 > 0:09:01Some fish are incurably inquisitive.
0:09:01 > 0:09:05The little egret can attract them
0:09:05 > 0:09:08by doing no more than waggle its yellow feet.
0:09:17 > 0:09:22It seems a simple enough trick but it works nonetheless.
0:09:24 > 0:09:29Birds all over the world have worked out all kinds of bizarre solutions
0:09:29 > 0:09:34to the problem of extracting little fish from shallow pools.
0:09:35 > 0:09:40In the Florida swamps, the reddish egret performs an improbable dance.
0:09:45 > 0:09:51The idea seems to be to frighten the fish out of their hiding places.
0:10:15 > 0:10:22Shading your eyes can help you see what's down there beneath the reflections.
0:10:24 > 0:10:26And there WAS something.
0:10:30 > 0:10:37In Africa, the black heron takes the business of shading its eyes very seriously indeed.
0:10:50 > 0:10:55Maybe cutting out reflections is not the only reason for doing this.
0:10:55 > 0:11:02Many fish prefer to swim beneath an overhanging bank or a tree, so that they can't be easily seen from above.
0:11:02 > 0:11:07So perhaps they deliberately shelter under the heron's wings -
0:11:07 > 0:11:10which, of course, could be a mistake.
0:11:41 > 0:11:44The spoonbill isn't really after fish.
0:11:44 > 0:11:49This scything action enables it to gather tadpoles, beetles and larvae,
0:11:49 > 0:11:55but it must also scare little fish which then dash off to seek safety.
0:11:55 > 0:12:02So it's worthwhile for the black heron to follow the spoonbill around - just in case.
0:12:20 > 0:12:28The pygmy cormorant certainly IS after fish - and therefore thinks it's a good idea to follow the heron.
0:12:28 > 0:12:31Maybe the heron is having better luck.
0:12:42 > 0:12:47A little fish doesn't stand much of a chance in a shallow pool like this.
0:12:49 > 0:12:55These too are fishermen, but they don't wade - they skim.
0:12:55 > 0:13:00And to do that they need not long legs but a long beak.
0:13:00 > 0:13:04Or, to be more accurate, a long lower mandible.
0:13:04 > 0:13:07The upper one is more or less normal in size.
0:13:07 > 0:13:12This is the skimmer - a highly specialised relation of the gulls.
0:13:19 > 0:13:24Their chicks, in fact, look very like gull chicks.
0:13:28 > 0:13:35They don't develop that extraordinary beak until they are some three months old.
0:13:35 > 0:13:40Skimming, although it demands flying of the greatest precision,
0:13:40 > 0:13:44is straightforward enough in principle.
0:13:44 > 0:13:51As soon as the lower mandible, ploughing through the surface of the water, touches anything solid,
0:13:51 > 0:13:54a reflex action makes it snap shut.
0:13:54 > 0:13:57That sounds fine,
0:13:57 > 0:14:03but suppose the beak hits something really big, like a floating twig or, worse, a submerged rock - what then?
0:14:03 > 0:14:08Well, the fact is that quite a lot of skimmers have broken mandibles.
0:14:30 > 0:14:35Whatever the hazards, overall, the technique is successful one.
0:14:35 > 0:14:40The chicks have to be fed for six weeks.
0:14:40 > 0:14:47Skimmers are faithful, hardworking parents, bringing food every ten minutes or so for hours on end
0:14:47 > 0:14:50 when the fishing is good.
0:14:52 > 0:14:57But while they are certainly devoted to their young,
0:14:57 > 0:15:00they are sometimes just a little optimistic.
0:15:04 > 0:15:07CHICK TRILLS
0:15:28 > 0:15:32Ah, well - if baby doesn't want it...
0:15:36 > 0:15:41Skimmers and egrets and kingfishers live beside the water.
0:15:41 > 0:15:45Some birds live actually on it.
0:15:45 > 0:15:52Mallards must be one of the most familar birds in the world, and so perhaps we take ducks for granted.
0:15:52 > 0:15:59But they are a very varied family. Different species are adapted to different ways of life on water.
0:15:59 > 0:16:03Mallard, for example, are specialist dabblers.
0:16:04 > 0:16:07They find all the food they need
0:16:07 > 0:16:13by doing no more than dipping their heads and necks beneath the surface.
0:16:13 > 0:16:16And there's lots to be found -
0:16:16 > 0:16:19duckweed and tadpoles, leaves and seeds
0:16:19 > 0:16:23and bits of bread thrown in by friendly humans.
0:16:42 > 0:16:47If the food is really deep down, they will up-end totally.
0:16:47 > 0:16:50If that doesn't get it,
0:16:50 > 0:16:55then it's beyond their reach and that's that.
0:16:55 > 0:16:58Ducks keep their plumage water-resistant
0:16:58 > 0:17:03by anointing it with oil from a gland on their rump.
0:17:03 > 0:17:08They also keep their feathers clean, soft and pliant
0:17:08 > 0:17:12by frequent and enthusiastic bathing.
0:17:15 > 0:17:18Ducks don't all just dabble.
0:17:18 > 0:17:21Some dive deeper.
0:17:22 > 0:17:28The merganser has webbed feet like the mallard and all other ducks,
0:17:28 > 0:17:32but they are placed very far back on the body.
0:17:32 > 0:17:38It's the best place for a propeller and they swim fast enough to catch small fish.
0:17:43 > 0:17:47Their bills are notched like a fine saw,
0:17:47 > 0:17:52 which helps when you have to grapple with a slippery fish.
0:17:53 > 0:17:58The young start diving almost as soon as they hatch.
0:17:58 > 0:18:04But they are still covered in down and that makes swimming under water very difficult indeed,
0:18:04 > 0:18:11and they use up far more energy than their streamlined parents do.
0:18:42 > 0:18:48The most skilful swimmer of all freshwater birds, is the diver.
0:18:48 > 0:18:54This young one has not yet got its spectacular black and white plumage.
0:18:54 > 0:19:00Its feet are so far back on its body that out of water it can hardly walk,
0:19:00 > 0:19:04but underwater it's superbly manoeuvrable.
0:19:04 > 0:19:07Small fish have little chance.
0:19:13 > 0:19:16Diver chicks are covered with down.
0:19:16 > 0:19:20That's very useful for keeping warm
0:19:20 > 0:19:26but, as the mergansers demonstrated, it causes problems when diving
0:19:26 > 0:19:29 and young divers don't even try.
0:19:29 > 0:19:34Diver chicks, it has to be said, are rather pampered.
0:19:34 > 0:19:36They are regularly given lifts
0:19:36 > 0:19:44and, while one of their parents ferries them around, the other goes to find food for them.
0:19:51 > 0:19:56The male finds a fish - but decides to eat that himself.
0:20:00 > 0:20:05He's been away a long time and the family is getting hungry.
0:20:09 > 0:20:12But now he's found a crayfish.
0:20:12 > 0:20:15That will do for them.
0:20:19 > 0:20:22The crayfish is carefully broken up
0:20:22 > 0:20:27and passed over to the chicks, a little piece at a time,
0:20:27 > 0:20:29with great delicacy
0:20:29 > 0:20:32 and quite a lot of patience.
0:20:49 > 0:20:51Lakes have a tendency to shrink.
0:20:51 > 0:20:58They get shallower as rivers dump sediment and, in the tropics, may even dry up every year.
0:20:58 > 0:21:04Then all sorts of delicious things come within reach, as in this African pool.
0:21:06 > 0:21:11The openbill stork has a special liking for mussels
0:21:11 > 0:21:14 and a special way of opening them.
0:21:14 > 0:21:17A sharp squeeze to make the shell open slightly,
0:21:17 > 0:21:22then the lower mandible is slipped in to cut the body from the shell.
0:21:27 > 0:21:30 After that, it's easy.
0:21:38 > 0:21:42Snails require a slightly different treatment.
0:21:42 > 0:21:47To start with, they have to be taken on to solid ground.
0:21:48 > 0:21:53Now, the little disc with which the snail can seal its shell
0:21:53 > 0:21:58has to be removed by delicately squeezing it in just the right place.
0:22:05 > 0:22:07 There!
0:22:10 > 0:22:17Then, once again, the muscle that attaches the snail to its shell has got to be severed.
0:22:17 > 0:22:20And out it comes.
0:22:33 > 0:22:35As the dry season progresses,
0:22:35 > 0:22:42yellow-billed storks travel in flocks from one drying river bed to another.
0:22:42 > 0:22:45When the water started to shallow,
0:22:45 > 0:22:48 many fish withdrew to the main river.
0:22:48 > 0:22:51Those that didn't are now doomed.
0:22:53 > 0:22:56The yellow-bills have a labour-saving technique
0:22:56 > 0:23:00for fishing in these overcrowded pools -
0:23:00 > 0:23:05they open their beaks and wait for a fish to blunder into them.
0:23:12 > 0:23:17Only one kind of fish is likely to survive the coming drought.
0:23:17 > 0:23:21The lungfish will soon cocoon itself in the mud
0:23:21 > 0:23:26and remain there, dormant but alive, even when the river bed is bone dry,
0:23:26 > 0:23:29 because it can breathe air.
0:23:39 > 0:23:44But before it cocoons, it has to survive another peril.
0:23:49 > 0:23:54The shoebill stork has a massive and murderous beak.
0:24:00 > 0:24:03It also has keen eyes...
0:24:10 > 0:24:13..and infinite patience.
0:24:43 > 0:24:46One bite crushes the lungfish's skull.
0:24:57 > 0:25:03But it still wriggles - and takes quite a bit of swallowing.
0:25:27 > 0:25:34On the margins of the land, the water retreats not just once a year but twice every day.
0:25:34 > 0:25:38That exposes a completely different menu
0:25:38 > 0:25:42and birds compete to be the first to collect it.
0:25:42 > 0:25:49Here in California, there are some that take almost suicidal risks in order to do so.
0:25:59 > 0:26:02The surf bird is the clear winner.
0:26:02 > 0:26:08No bird gets to an edible morsel cast up by the waves quicker than it does.
0:26:19 > 0:26:21It has split-second judgment.
0:26:42 > 0:26:46It may also be that it gets so close to the waves
0:26:46 > 0:26:52because that gives it the chance of catching a barnacle or a mussel
0:26:52 > 0:26:59before it has fully reacted to its exposure to the air and closed its shell.
0:27:33 > 0:27:38Where the coast is less rocky, the waves are less violent.
0:27:39 > 0:27:43Here birds of several kinds will assemble.
0:27:43 > 0:27:47But they are not always in competition.
0:27:47 > 0:27:54Each collects from a particular place with a particular kind of implement.
0:27:54 > 0:28:01The godwits have long beaks with which to probe deeply into the sand for worms, crustaceans and molluscs.
0:28:01 > 0:28:07Dowitchers, with shorter beaks, collect much the same sort of thing
0:28:07 > 0:28:10 but from nearer the surface.
0:28:20 > 0:28:26Sanderlings pick up bits and pieces that have just been washed ashore.
0:28:35 > 0:28:41In the shallow water, avocets are after shrimps and other creatures
0:28:41 > 0:28:45that don't allow themselves to get stranded on the beach.
0:28:45 > 0:28:49The avocet holds its bill just slightly parted
0:28:49 > 0:28:54and, as it sweeps it through the water and the mud,
0:28:54 > 0:28:57small invertebrates are carried into it.
0:28:57 > 0:29:02The avocet can feel when something good has arrived
0:29:02 > 0:29:06and can quickly swallow it.
0:29:06 > 0:29:10Fish come into the shallows for the same reason.
0:29:13 > 0:29:18And when they do, THEY become the target of pelicans.
0:29:23 > 0:29:28With a bill the size of a pelican's you don't need pin-point accuracy.
0:29:32 > 0:29:35It does help, however, to feed in groups.
0:29:35 > 0:29:38Fish fleeing from one lunging bill
0:29:38 > 0:29:41 may blunder into another.
0:29:41 > 0:29:44The brown pelican also dives.
0:29:49 > 0:29:51But rather clumsily.
0:29:51 > 0:29:56It is so big and buoyant that it only goes a few feet down.
0:29:56 > 0:29:59Noddy terns often accompany it.
0:29:59 > 0:30:04They know the pelican will have to open its bill to empty the water
0:30:04 > 0:30:07before it can swallow any fish.
0:30:07 > 0:30:12And when it does, THEY might get a chance to steal part of its catch.
0:30:34 > 0:30:39So now it's a question of who loses patience first.
0:30:49 > 0:30:54The pelican cautiously opens its bill just slightly -
0:30:54 > 0:30:58and the water begins to seep from its pouch.
0:31:12 > 0:31:15Done it - this time.
0:31:22 > 0:31:26Boobies live on the coast, but their fishing grounds
0:31:26 > 0:31:29 are way out in the open ocean.
0:31:29 > 0:31:33Every morning they leave their roosts
0:31:33 > 0:31:38 and set off in small parties to scour the surface of the sea.
0:31:41 > 0:31:46They are searching for a pale greenish patch
0:31:46 > 0:31:50that betrays the presence of a dense shoal of fish.
0:31:50 > 0:31:57The fish have been driven to the surface by a shark that is still lunging into the shoal.
0:32:02 > 0:32:06And now they are subject to an aerial bombardment.
0:32:23 > 0:32:28As the boobies dive, they draw their wings half back
0:32:28 > 0:32:31 so that they can still aim,
0:32:31 > 0:32:34and only fully retract them
0:32:34 > 0:32:37 just before they hit the water.
0:33:20 > 0:33:26The bombardment will go on until the shoal manages to escape downwards
0:33:26 > 0:33:33or the fading light of the evening forces the boobies to return to their roost on the coast.
0:33:39 > 0:33:43Boobies don't actively swim underwater,
0:33:43 > 0:33:48but members of the auk family, such as these guillemots and puffins, do.
0:33:54 > 0:33:57They propel themselves with their wings
0:33:57 > 0:34:03and they have paid a considerable price to be able to do so.
0:34:03 > 0:34:09The wings of a booby or gull are too long and insufficiently robust to be beaten underwater.
0:34:09 > 0:34:14So auks have had to evolve shorter, stubbier wings.
0:34:14 > 0:34:17It gives them a rather clumsy flight
0:34:17 > 0:34:22but it does enable them to "fly" underwater so well
0:34:22 > 0:34:25 that they can outpace small fish.
0:34:40 > 0:34:45One family of birds has taken this development even farther
0:34:45 > 0:34:48and one of them lives here in the Galapagos.
0:34:49 > 0:34:57We tend to think of penguins as sitting around on ice floes in the freezing waters of the Antarctic,
0:34:57 > 0:35:02so maybe these little penguins right on the equator seem odd to us.
0:35:02 > 0:35:09But these are probably much more like the original ancestral penguin than their giant Antarctic cousins.
0:35:09 > 0:35:14Because those ancestral penguins certainly flew as well as dived.
0:35:14 > 0:35:20And if you were much bigger, with a wing shaped like a flipper,
0:35:20 > 0:35:23which all penguins use to swim,
0:35:23 > 0:35:25you would never get into the air.
0:35:25 > 0:35:30So, maybe, these little ones are more like the first of the penguins.
0:35:53 > 0:35:57Penguins underwater look somewhat like dolphins
0:35:57 > 0:36:02and indeed the two families have similar evolutionary histories.
0:36:02 > 0:36:09Dolphins are descended from air-breathing land animals, penguins from air-breathing flying animals.
0:36:09 > 0:36:12Both took to swimming for their food,
0:36:12 > 0:36:16becoming beautifully adapted and streamlined.
0:36:16 > 0:36:23And now both are superlative swimmers and highly accomplished fishermen.
0:36:45 > 0:36:52Some members of the penguin family can dive for five or six minutes without taking breath
0:36:52 > 0:36:56and descend to depths of 1,000 feet in search of food.
0:37:03 > 0:37:10Indeed, the only thing that limits penguins as swimmers is their need to breathe air.
0:37:10 > 0:37:16But there is one link that still ties them - and all birds - to the land.
0:37:16 > 0:37:22They all have to return there in order to lay their eggs.
0:37:22 > 0:37:25For sea birds, the ideal place to do that
0:37:25 > 0:37:32is a remote island which has very few, or preferably no land-living predators.
0:37:32 > 0:37:35BIRD CALLS
0:37:35 > 0:37:37HE CALLS AGAIN
0:37:41 > 0:37:43BIRD REPLIES
0:37:47 > 0:37:50Nobody knows why it happens,
0:37:50 > 0:37:55but when you make strange noises here, sea birds fall from the sky.
0:37:55 > 0:38:02I am on Lord Howe Island, a tiny speck of land 300 miles off the east coast of Australia.
0:38:02 > 0:38:06Human beings only got here about 200 years ago
0:38:06 > 0:38:11and the birds that nest here still seem curious to see what is going on.
0:38:11 > 0:38:15And these birds which are coming to these calls
0:38:15 > 0:38:17are Providence petrels.
0:38:22 > 0:38:25BIRDS SHRIEK
0:38:29 > 0:38:33Skilled in the air they may be,
0:38:33 > 0:38:38but they are certainly clumsy and ungainly on land.
0:38:38 > 0:38:44And when they do come down, they squabble and wrestle furiously with one another.
0:38:44 > 0:38:49Perhaps they are arguing about which patch to have for a nest hole.
0:38:51 > 0:38:56But they are still extraordinarily friendly towards human beings.
0:39:02 > 0:39:05And amazingly, and very touchingly,
0:39:05 > 0:39:10it will stay here on my hand in a very trusting way.
0:39:10 > 0:39:15It gives me a chance to look at this structure at the base of his beak.
0:39:15 > 0:39:19He has a tube-nose
0:39:19 > 0:39:25and that structure, which he shares with a number of other ocean-going birds,
0:39:25 > 0:39:30is absolutely crucial to their survival out on the open ocean.
0:39:30 > 0:39:34And that is where he is going to go right now.
0:39:52 > 0:39:56That tube channels air to a sense organ at the base of the beak
0:39:56 > 0:40:00which can detect very faint odours.
0:40:00 > 0:40:04That's a rare ability, and it enables the tube-noses
0:40:04 > 0:40:08to find floating food from great distances away.
0:40:23 > 0:40:29I'm at sea, 20 miles out from the east coast of Australia.
0:40:29 > 0:40:33And in this bucket I have got a particularly attractive liquid.
0:40:33 > 0:40:39HE SNIFFS
0:40:36 > 0:40:39It's fish oil, it's very nutritious.
0:40:39 > 0:40:42Being oil, it will float on the sea
0:40:42 > 0:40:46and, above all, it smells very powerfully.
0:40:46 > 0:40:49At the moment, there's not a bird in sight.
0:40:49 > 0:40:54But watch what happens when I put it overboard.
0:41:08 > 0:41:11BIRD CALLS
0:41:16 > 0:41:21First to arrive are sooty shearwaters and Cape petrels -
0:41:21 > 0:41:27closely related to those Providence petrels on Lord Howe Island.
0:41:34 > 0:41:39It's not only the smell of fish oil and offal to which they're sensitive.
0:41:39 > 0:41:46It's been discovered that when small shrimps and other floating creatures feed on floating plants,
0:41:46 > 0:41:51those plants release a gas that smells a little like rotting seaweed.
0:41:51 > 0:41:56The petrels can sense even the faintest whiff of this
0:41:56 > 0:42:00and so can find places to collect the shrimps.
0:42:03 > 0:42:07Now, very much bigger ocean-going birds arrive.
0:42:22 > 0:42:25BIRDS CLUCK AND CAW
0:42:39 > 0:42:43These magnificent birds are albatrosses.
0:42:43 > 0:42:50They too are members of the tube-nose family, but the tube on their beaks is comparatively small
0:42:50 > 0:42:54and in fact THEY find their food more by sight than by smell.
0:42:54 > 0:42:57But they have enormous wingspans.
0:42:57 > 0:43:03The royal albatross and the wandering albatross have the biggest wingspan of any living bird.
0:43:03 > 0:43:08And they circle the globe in search of food.
0:43:10 > 0:43:13This is a yellow-nosed albatross.
0:43:13 > 0:43:20It is not quite as big as a wanderer but it is still a very large bird with a seven-foot wingspan.
0:43:22 > 0:43:27No bird exploits the ocean winds with greater skill than an albatross.
0:43:27 > 0:43:29Reading its force with peerless sensitivity,
0:43:29 > 0:43:32 they are able to adjust their immense wings
0:43:32 > 0:43:37to exploit every tiny updraught deflected from the waves beneath.
0:43:37 > 0:43:44So they can glide for long periods without expending any energy at all on flapping.
0:43:44 > 0:43:48The wandering albatross rides the violent gales of the southern ocean,
0:43:48 > 0:43:55and will travel a thousand miles to bring back a cropful of food for its chick.
0:43:59 > 0:44:01SHRILL CRIES
0:44:05 > 0:44:08CHICK CRIES AGAIN
0:44:10 > 0:44:15It takes ten months to grow strong enough for an ocean-going life.
0:44:15 > 0:44:23So although the albatross when young may roam the oceans for several years without touching land,
0:44:23 > 0:44:27eventually the need to breed brings it down to earth.
0:44:29 > 0:44:33One bird has managed to break this long obligation
0:44:33 > 0:44:37to return repeatedly to land to feed its chick.
0:44:38 > 0:44:41It is called the ancient murrelet
0:44:41 > 0:44:45and it doesn't feed its chick on land at all.
0:44:45 > 0:44:50It only nests on islands around the northern rim of the Pacific,
0:44:50 > 0:44:55like Canada's Queen Charlotte Islands, where I am now.
0:44:55 > 0:44:58And you're only likely to see it at night.
0:45:00 > 0:45:03This is one of their nest holes.
0:45:03 > 0:45:10The chicks, when they are only two DAYS old, make one of the most amazing journeys made by any chicks.
0:45:16 > 0:45:22The parents come back from the sea at night and, crouching, call to their newly hatched young.
0:45:24 > 0:45:28The chicks come out of their holes running.
0:45:28 > 0:45:32Large, aggressive mice will catch them if they get the chance.
0:45:32 > 0:45:38Ravens and eagles are also active during these light nights.
0:45:38 > 0:45:42The chicks are in real danger - so they run fast.
0:45:44 > 0:45:49Their parents have gone ahead and are now calling from the sea.
0:45:59 > 0:46:04By midnight, there are young chicks swarming all over the forest floor.
0:46:17 > 0:46:23Most of them manage to get to the beach within ten minutes of leaving their holes.
0:46:29 > 0:46:32But their parents are not here.
0:46:32 > 0:46:35They have gone farther out
0:46:35 > 0:46:38 and they're still calling.
0:46:43 > 0:46:48The chicks don't stop. They pedal on, like little clockwork toys
0:46:48 > 0:46:55and the movements that propelled them across the ground now take them out to sea.
0:47:00 > 0:47:03In some miraculous way,
0:47:03 > 0:47:08each chick recognises the sound of its parent's voice.
0:47:18 > 0:47:22United, the little families leave the land and its dangers
0:47:22 > 0:47:26and sail into the relative safety of the open ocean.
0:47:26 > 0:47:30The chicks are still only a few hours old.
0:47:30 > 0:47:36The ancient murrelet must be the most truly oceanic of all birds.
0:47:44 > 0:47:46Dawn...
0:47:46 > 0:47:49and there is not a single little chick to be seen.
0:47:49 > 0:47:56By now they are all at least four miles out to sea, called there by their parents.
0:47:56 > 0:48:02Sound, of course, is important in the life of ALL birds. It's how they communicate.
0:48:02 > 0:48:07And what they say, and the various ways in which they say it,
0:48:07 > 0:48:12is what we will look at in the next programme about the life of birds.
0:48:44 > 0:48:48Subtitles by Mairi Macleod BBC Scotland - 1998