The Problem of Parenthood

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0:00:34 > 0:00:37CROAKY CHIRPING

0:00:40 > 0:00:46For this brown pelican, the problems of bringing new life into the world

0:00:46 > 0:00:50have started even before the eggs have hatched.

0:00:50 > 0:00:55They've had to be kept cool or warm, according to the time of day,

0:00:55 > 0:01:00and they've had to be defended. But that's only the beginning of things!

0:01:24 > 0:01:27FEEBLE CHIRPING

0:01:39 > 0:01:44Once their chicks have disentangled themselves from their shells,

0:01:44 > 0:01:52the first job of the brown pelicans here in Florida, as with all bird parents, is to find food urgently.

0:01:53 > 0:01:58Few are in a greater hurry than the Lapland bunting,

0:01:58 > 0:02:01for summer in the Arctic is desperately short.

0:02:01 > 0:02:04Food is rushed in,

0:02:04 > 0:02:08droppings are ferried out...

0:02:08 > 0:02:10Both parents labour tirelessly

0:02:10 > 0:02:15and since it's light 24 hours a day at this time of the year,

0:02:15 > 0:02:18they do so nonstop.

0:02:21 > 0:02:25As a consequence, the chicks grow at extraordinary speed

0:02:25 > 0:02:29and only 12 days after hatching, they will fledge.

0:02:45 > 0:02:49Dippers are also dedicated and industrious parents.

0:03:04 > 0:03:11A nest behind a waterfall is excellently concealed but tricky to visit.

0:03:12 > 0:03:20Nonetheless, these dippers, between them, bring a batch of food to their young every ten minutes.

0:03:56 > 0:04:00Gouldian finches in Australia make their nests

0:04:00 > 0:04:02 in holes in trees.

0:04:03 > 0:04:08The disadvantage of doing that is that it may be so gloomy within

0:04:08 > 0:04:13that it's difficult to see where the chicks are.

0:04:13 > 0:04:17The solution - vividly coloured spots

0:04:17 > 0:04:19 on the side of the mouth.

0:04:22 > 0:04:29And when vibrations made by a parent as it enters tell these still blind chicks that food is on the way,

0:04:29 > 0:04:33they quickly provide extra guidance.

0:04:33 > 0:04:37With gapes patterned as vividly as this,

0:04:37 > 0:04:42the parents have no doubt about where to post their food parcels.

0:05:15 > 0:05:18These are zebra finches.

0:05:23 > 0:05:29And these extraordinary objects are young firetail finches.

0:05:29 > 0:05:36What look like goggles are actually markers to indicate the corners of the mouth.

0:05:48 > 0:05:54These are the chicks of Australian rosella parrots.

0:05:54 > 0:05:59Their parents started incubating as soon as their first egg was laid.

0:05:59 > 0:06:05That, therefore, was the first to hatch and its chick, the first to be fed.

0:06:05 > 0:06:09So at first, there's a difference in size between the chicks.

0:06:09 > 0:06:14But rosella parents are scrupulously fair and they make quite sure

0:06:14 > 0:06:19that even the youngest gets its proper share of food.

0:06:28 > 0:06:33Even so, after ten days, the eldest is still the biggest.

0:06:35 > 0:06:38But remarkably,

0:06:38 > 0:06:43it sometimes shares its food with the youngest and the smallest.

0:06:48 > 0:06:51They're beginning to lose their down

0:06:51 > 0:06:55 and proper feathers start showing through.

0:06:55 > 0:06:58An itchy business, apparently.

0:07:05 > 0:07:08HIGH-PITCHED CHIRPING

0:07:09 > 0:07:16Three weeks later, in spite of five days' difference in age between the oldest and the youngest,

0:07:16 > 0:07:24they're all the same size. Rosellas feed the chicks with a regurgitated porridge of chewed up seeds.

0:07:24 > 0:07:29Great crested grebes, on the other hand,

0:07:29 > 0:07:33offer their newly-hatched young much stranger meals.

0:07:40 > 0:07:42Feathers.

0:07:45 > 0:07:53It's not a mistake or an occasional quirk. Swallowing feathers is essential for the health of grebes.

0:07:53 > 0:07:55They form a lining in the stomach

0:07:55 > 0:08:02which protects it from the sharp bones of fish - the main part of a grebe's diet.

0:08:02 > 0:08:09When the chicks grow up, they'll swallow their own feathers, but now their parents provide them.

0:08:13 > 0:08:18And that's just as well, considering the size of the fish

0:08:18 > 0:08:25that the youngsters are prepared to tackle early on in their young lives.

0:08:41 > 0:08:48These open-billed storks nesting in the sweltering heat of Thailand have also got young chicks.

0:08:48 > 0:08:56One of their problems is keeping cool and one of the ways of solving it is to take a nice cool shower.

0:08:56 > 0:09:00But some showers are nicer than others!

0:09:03 > 0:09:07The adults bring water back to the nest in their crops

0:09:07 > 0:09:11and empty it over the featherless chicks.

0:09:26 > 0:09:31But showers are not the only things that the chicks need.

0:09:31 > 0:09:38Sitting virtually naked in the baking sun could be lethal. During the hottest part of the day,

0:09:38 > 0:09:43they're in desperate need of shade and the parents provide it.

0:09:56 > 0:10:00The storks, like many birds, are exemplary parents,

0:10:00 > 0:10:05tending to the needs of their offspring with care and devotion.

0:10:05 > 0:10:09But not all birds behave in such a way.

0:10:20 > 0:10:22It's an idyllic scene.

0:10:22 > 0:10:27A pair of birds devotedly caring for their chicks in the springtime.

0:10:27 > 0:10:33But for the adult birds it's a very testing time, particularly if,

0:10:33 > 0:10:41like these coots, you may have as many as nine chicks and the food supply is far from certain.

0:10:44 > 0:10:47Things start well enough.

0:10:47 > 0:10:50One of the adults uses particles of food

0:10:50 > 0:10:53to tempt a newly-hatched chick

0:10:53 > 0:10:57down from the nest and onto the water.

0:11:01 > 0:11:07The little flotilla sets off under the care of both parents.

0:11:14 > 0:11:21But the food they prefer comes in very small instalments - tiny shrimps and water insects.

0:11:21 > 0:11:24It takes a lot of collecting.

0:11:40 > 0:11:44And there are other troubles and stresses.

0:11:44 > 0:11:49Trespassers can't be allowed onto the coots' feeding grounds.

0:11:49 > 0:11:53They have to be seen off, no matter how big they are.

0:12:02 > 0:12:05Then, nearly always on the third day,

0:12:05 > 0:12:11the parents begin to lose patience. A chick begs for food yet again...

0:12:13 > 0:12:15..and is punished.

0:12:24 > 0:12:29Each chick in turn gets this harsh treatment.

0:12:40 > 0:12:45Maybe the adults are testing them to see which are the strongest.

0:12:57 > 0:13:02After a time, they concentrate their punishment on one,

0:13:02 > 0:13:04and to such a degree

0:13:04 > 0:13:08that it stops begging and so starves to death.

0:13:10 > 0:13:15But unless there is a superabundance of food, the persecution goes on.

0:13:20 > 0:13:24In the end, the coots will only raise two or three

0:13:24 > 0:13:27out of their brood of nine.

0:13:30 > 0:13:36Life for young pelicans can be equally brutal. As they grow, so do their appetites.

0:13:47 > 0:13:49No matter how hard the parents work,

0:13:49 > 0:13:54they cannot bring enough food for all three.

0:14:00 > 0:14:04The last to hatch was always smaller than the other two.

0:14:04 > 0:14:10It was always the last to be fed and now the two older ones turn on it.

0:14:38 > 0:14:41Now it will not survive.

0:14:41 > 0:14:46Its parents will not bring any food to it on the ground.

0:14:47 > 0:14:50And that's not the end of it.

0:14:50 > 0:14:57No sooner has one been pushed out of the nest, than a second will follow until there's only one left.

0:14:57 > 0:15:02That's what happens nearly always in a pelican's nest.

0:15:02 > 0:15:09It seems rather inefficient, not to say heartless, that the pelican should always lay three eggs.

0:15:09 > 0:15:12But it's partly an insurance policy -

0:15:12 > 0:15:19if something happens to one or two of the chicks, there's always a third left to carry on.

0:15:19 > 0:15:26And it's partly because very rarely, when the fishing's very good, it IS possible to raise more than one.

0:15:42 > 0:15:47So, bringing up the young is a very demanding business indeed.

0:15:47 > 0:15:53For most birds, it requires the full-time labour of both male and female.

0:15:53 > 0:15:57But one or two birds manage to avoid it altogether.

0:15:57 > 0:16:03One of them is a regular visitor to this reed bed in England.

0:16:03 > 0:16:07A cuckoo, and she's raiding a reed warbler's nest.

0:16:15 > 0:16:19That's one of the reed warbler's eggs gone.

0:16:29 > 0:16:32And while she holds a second in her beak,

0:16:32 > 0:16:36shuddering with the effort, she lays one of her own.

0:16:40 > 0:16:45A near perfect match - the cuckoo's is the front one.

0:16:45 > 0:16:50The reed warblers don't notice the difference and continue incubation.

0:16:50 > 0:16:53The cuckoo has timed her action with care.

0:16:53 > 0:17:00She laid her egg immediately after the female reed warbler laid the last of hers,

0:17:00 > 0:17:07but it develops much faster and will hatch three or four days before the legitimate eggs do.

0:17:20 > 0:17:23The young cuckoo, blind and naked,

0:17:23 > 0:17:27now deals with the remaining warbler eggs.

0:17:39 > 0:17:47Two weeks later, the monstrous young cuckoo is so big that it can no longer fit inside the tiny nest.

0:17:49 > 0:17:52Its brilliantly-coloured gape,

0:17:52 > 0:17:59together with its call that mimics the sound of a whole brood of warbler chicks,

0:17:59 > 0:18:07constitute a demand for food that the warblers find irresistible. LONG, SHIVERING TRILL

0:18:07 > 0:18:10The European cuckoo's habit is so famous

0:18:10 > 0:18:15that we tend to think it's the only bird to behave in this way.

0:18:15 > 0:18:21But there are birds in half a dozen other families that do so as well.

0:18:27 > 0:18:32Here in Argentina, brown-hooded gulls are nesting.

0:18:36 > 0:18:39Gulls are so vigorous and enterprising

0:18:39 > 0:18:44that they might seem the last birds likely to be tricked...

0:18:44 > 0:18:47but, on occasion, they are.

0:19:02 > 0:19:04A duckling!

0:19:04 > 0:19:08Its true parents,

0:19:08 > 0:19:13cuckoo ducks, are far away from the nest where they dumped their egg.

0:19:13 > 0:19:19Their offspring will never see them, just as they never saw their parents.

0:19:23 > 0:19:28The duckling cannot know that it's quite different from the baby gull

0:19:28 > 0:19:32which has now hatched out alongside it.

0:19:32 > 0:19:34Nonetheless, something tells it

0:19:34 > 0:19:39that it must not stay with this other nestling.

0:19:39 > 0:19:42On its very first evening,

0:19:42 > 0:19:44it leaves.

0:19:51 > 0:19:58Unlike the cuckoo, it makes no further demands on the bird that incubated it.

0:19:58 > 0:20:02Even though it's only a few hours old,

0:20:02 > 0:20:06it's perfectly capable of fending for itself.

0:20:07 > 0:20:12Young goldeneyes also have a somewhat precipitate start to life.

0:20:20 > 0:20:24The female goldeneye often lays in a woodpecker's hole.

0:20:27 > 0:20:33But when her young have got over that handicap, she leads them down to water -

0:20:33 > 0:20:37the only place where they, like most ducklings,

0:20:37 > 0:20:40can gather food for themselves.

0:20:41 > 0:20:46Here in British Columbia there's no shortage of lakes,

0:20:46 > 0:20:51and their mother goes ahead and calls for them to join her.

0:20:51 > 0:20:54RAPID QUACKING

0:20:55 > 0:20:58EXCITED CHIRPING

0:21:08 > 0:21:15This lake, however, has already been claimed by another female goldeneye with her brood,

0:21:15 > 0:21:18and she is very possessive.

0:21:18 > 0:21:20There's going to be trouble.

0:21:55 > 0:21:57The newcomer...

0:21:57 > 0:21:59has to leave.

0:22:06 > 0:22:10But her ducklings can't fly away with her.

0:22:15 > 0:22:18So, they join the resident family.

0:22:23 > 0:22:28That's no problem for mother - they can fend for themselves.

0:22:28 > 0:22:33And an enlarged family reduces the chances of her own ducklings

0:22:33 > 0:22:37being taken by a hungry fish or a hawk.

0:22:40 > 0:22:45In the end, she may accumulate a flock of 20 or more.

0:22:54 > 0:22:57A river in the high Andes.

0:22:57 > 0:22:59Unlikely though it may seem,

0:22:59 > 0:23:04some ducks manage to live on these racing waters as well -

0:23:04 > 0:23:07torrent ducks.

0:23:08 > 0:23:11SHRILL WHISTLE These have made their nest

0:23:11 > 0:23:14in the rocks 30 feet above the water -

0:23:14 > 0:23:19high enough to be safe if the river were suddenly to rise.

0:23:25 > 0:23:32But that means that these ducklings also have a very hazardous journey to make.

0:23:32 > 0:23:34Even mother has a little trouble.

0:23:34 > 0:23:37DUCKLINGS CHIRP

0:24:07 > 0:24:12The racing water might seem to pose even more problems than the rocks,

0:24:12 > 0:24:17but the ducklings are so buoyant that they float on the surface

0:24:17 > 0:24:23and are in no danger of drowning. Nor are they swept away,

0:24:23 > 0:24:30for, miraculously, they know instinctively how to shelter in the eddies in the lee of a boulder.

0:24:30 > 0:24:35And once launched, they too can feed for themselves.

0:25:36 > 0:25:39Summer on the Arctic tundra.

0:25:39 > 0:25:46Brent geese came up here a few weeks ago to feed on the newly-spouting vegetation

0:25:46 > 0:25:48and to nest.

0:25:48 > 0:25:55Their newly-hatched offspring also have to face a dangerous journey before they can feed.

0:26:03 > 0:26:09This pair built their nest within a few yards of a snowy owl's nest.

0:26:09 > 0:26:15That was good sense, for ground-nesting birds here are likely to be attacked by foxes.

0:26:22 > 0:26:26Owls are quite prepared to tackle foxes...

0:26:27 > 0:26:31..and so they seldom venture near.

0:26:36 > 0:26:40While incubating, the geese benefited greatly

0:26:40 > 0:26:43by nesting beside such powerful neighbours.

0:26:43 > 0:26:47But now the eggs are hatching, which changes things.

0:26:49 > 0:26:52Owls feed on lemmings...

0:26:53 > 0:26:57..and lemmings are about the same size as goslings.

0:27:05 > 0:27:08Somehow these little creatures

0:27:08 > 0:27:13will have to avoid becoming one more meal for a hungry owl.

0:27:17 > 0:27:22But they must leave their nest if they are not to starve.

0:27:23 > 0:27:28Their parents are well aware of the danger.

0:27:34 > 0:27:39Equally, the male owl can see that there's a meal to be had.

0:27:53 > 0:27:56CLUCKING AND CACKLING

0:28:31 > 0:28:34Parental bravery wins the day.

0:28:38 > 0:28:42Two birds to guard the young are good,

0:28:42 > 0:28:44three are even better.

0:28:44 > 0:28:48Magpie geese live in Northern Australia.

0:28:48 > 0:28:53The journey their goslings must make in order to feed is also dangerous.

0:28:53 > 0:29:00Magpie males are very unusual in that they'll normally mate with two females

0:29:00 > 0:29:02who will both lay in the same nest.

0:29:02 > 0:29:09So it's usually three adults, and only occasionally two, that escort their young.

0:29:10 > 0:29:12In the skies above, a sea eagle.

0:29:16 > 0:29:19It spots a trio with chicks...

0:29:27 > 0:29:30..and they manage to see it off.

0:29:44 > 0:29:46A pair are an easier target.

0:30:11 > 0:30:16Angry and brave the two adults may be, but it's too late.

0:30:27 > 0:30:31Attacks can come not only from the sky,

0:30:31 > 0:30:34but, more unexpectedly, from below.

0:30:42 > 0:30:44Crocodiles.

0:30:46 > 0:30:54Even the adults themselves are now in real danger and the goslings are very vulnerable indeed.

0:31:08 > 0:31:11The pair have made it,

0:31:11 > 0:31:14but only two of their five young have survived.

0:31:17 > 0:31:22The trios have succeeded in bringing down four or five chicks.

0:31:22 > 0:31:28Here in the feeding swamps there's comparative safety. All can join in keeping eagles away,

0:31:28 > 0:31:32and the water is too shallow for crocodiles.

0:31:32 > 0:31:36Nonetheless, overall, the journey cost many young lives.

0:31:36 > 0:31:40But the families that lost least were the trios.

0:31:40 > 0:31:43 There really is safety in numbers.

0:31:43 > 0:31:45AIR IS FILLED WITH BIRD CALL

0:31:45 > 0:31:51And here, in the Seychelles, numbers are astronomical -

0:31:51 > 0:31:53a million sooty terns.

0:31:53 > 0:31:58Here, surely, there must be safety from predators.

0:32:02 > 0:32:06But egrets stand around the fringes of the colony

0:32:06 > 0:32:10and will swiftly seize a chick if it's left unguarded.

0:32:10 > 0:32:12EGRET CAWS

0:32:34 > 0:32:36A chick is such a good meal

0:32:36 > 0:32:41that the egrets will risk stabs from the beak of a parent to get one.

0:32:50 > 0:32:52Further into the colony,

0:32:52 > 0:32:59the chicks are surrounded by a great crowd of adults and are much safer.

0:32:59 > 0:33:01Even a few yards from the edge,

0:33:01 > 0:33:08the egrets face such determined and effective opposition from all directions

0:33:08 > 0:33:11that they stand little chance of success.

0:33:11 > 0:33:14LOUD CACKLING ALL AROUND

0:33:31 > 0:33:35Chicks that have the luck to hatch in the very centre

0:33:35 > 0:33:41are five times more likely to survive than those on the edge.

0:33:41 > 0:33:45And there's another way for a bird to protect its chicks.

0:33:47 > 0:33:53Rear them in a place so remote that few other creatures can get there to threaten them.

0:33:53 > 0:33:56A place like the Australian desert.

0:33:56 > 0:34:02Here banded stilts nested beside a temporary lake. Soon after their eggs hatched,

0:34:02 > 0:34:06the females left and started nesting again elsewhere.

0:34:06 > 0:34:12Now the youngsters have gathered together in groups several hundred strong,

0:34:12 > 0:34:19with just a few males left behind to keep an eye on them. The job isn't too difficult,

0:34:19 > 0:34:26for the salty waters are full of tiny shrimps that the young stilts can collect for themselves.

0:34:30 > 0:34:33For other birds, however,

0:34:33 > 0:34:37finding food is so difficult that even two parents

0:34:37 > 0:34:40can't feed their chicks unaided.

0:34:40 > 0:34:45Farther south in Australia, white-winged choughs have that problem.

0:34:45 > 0:34:50Their young feed on beetle grubs and those are so difficult to excavate

0:34:50 > 0:34:57that a pair will need at least two adult helpers to keep one chick fully fed.

0:34:57 > 0:35:02The more helpers they have, the more chicks they can raise.

0:35:02 > 0:35:07This chick is almost fully grown and so has a very big appetite.

0:35:24 > 0:35:28All four birds labour away to keep it supplied.

0:35:32 > 0:35:38Eventually, however, it'll change from being a liability into an asset -

0:35:38 > 0:35:43a young bird that can help rear a chick next year.

0:35:46 > 0:35:51Another group of choughs appears in the trees.

0:35:56 > 0:35:58It has many more members.

0:36:02 > 0:36:05The residents are worried

0:36:05 > 0:36:10and show their agitation by goggling their eyes.

0:36:16 > 0:36:19This is a press gang. They're kidnappers.

0:36:29 > 0:36:32And this is what they're after.

0:36:33 > 0:36:41One of the raiders starts to display to the chick, trying to entice it away from its parental group.

0:36:43 > 0:36:45And it follows.

0:36:54 > 0:36:57A kidnapping has been achieved.

0:37:02 > 0:37:05The raiders feed their new recruit

0:37:05 > 0:37:10and it joins the group's own youngster.

0:37:16 > 0:37:21Now they have two juveniles. Next year's support team will be so big

0:37:21 > 0:37:26that they may be able to raise three or even four chicks.

0:37:26 > 0:37:32So having difficulties raising baby can lead to sociability among adults.

0:37:39 > 0:37:46But perhaps the most sociable of all birds, birds that behave almost like a troupe of little monkeys,

0:37:46 > 0:37:50live here in the deserts of the Middle East.

0:38:01 > 0:38:05An Arabian babbler - but you rarely see just one.

0:38:09 > 0:38:14Arabian babblers do everything together, if they possibly can.

0:38:14 > 0:38:18And that certainly includes taking a bath.

0:38:37 > 0:38:41After a bath, the whole group sunbathe together.

0:38:47 > 0:38:50Once dry, they preen each other.

0:39:15 > 0:39:20In fact, Arabian babblers do most things as a group.

0:39:26 > 0:39:32They all share the labour of collecting food for the group's chicks.

0:39:32 > 0:39:39They also share the responsibilities for defence, taking it in turn to act as sentry.

0:39:39 > 0:39:41When another sentry comes on duty,

0:39:41 > 0:39:47 it brings a morsel of food as part of the hand-over ritual.

0:39:53 > 0:39:56A viper.

0:39:58 > 0:40:01The sentry sounds the alarm.

0:40:02 > 0:40:06CHIRPING The whole group assembles.

0:40:06 > 0:40:11Their commotion ensures that everyone is aware of the danger.

0:40:11 > 0:40:16They also discomfort the snake and perhaps distract it from hunting.

0:40:16 > 0:40:18RAPID CHIRPING

0:40:23 > 0:40:26It may also be that some of them,

0:40:26 > 0:40:30by deliberately taunting the snake at close quarters,

0:40:30 > 0:40:34are demonstrating their strength and fitness

0:40:34 > 0:40:39in a way that will give them respect and seniority within the group.

0:40:45 > 0:40:49Once the danger is past, life returns to normal.

0:40:49 > 0:40:53The sentry goes back to guard duties...

0:40:53 > 0:40:57and the youngsters start to play among themselves.

0:41:07 > 0:41:14Many young birds are abandoned by their parents almost as soon as they can fly,

0:41:14 > 0:41:21so they have little chance to play and gain the skills they'll need as adults.

0:41:21 > 0:41:24But the babblers form such a coherent group

0:41:24 > 0:41:28that the juveniles can spend time doing just that.

0:41:28 > 0:41:34For the young anhingha in Florida, learning through play is essential.

0:41:34 > 0:41:40If it doesn't become a skilled juggler quickly, it will starve.

0:41:40 > 0:41:42 It must learn to do this.

0:42:08 > 0:42:14Of course, when playing with a stick, you mustn't take the game too far!

0:42:16 > 0:42:19Gannets also fish by diving -

0:42:19 > 0:42:24a skill that can't be practised by the young until they can fly.

0:42:26 > 0:42:28The parents deal with this problem

0:42:28 > 0:42:36by feeding their young so generously that by the time they've fledged into their dark, immature plumage,

0:42:36 > 0:42:43they've accumulated reserves of fat that will sustain them while they learn to catch fish for themselves.

0:42:43 > 0:42:47So now they're heavier than their parents.

0:42:47 > 0:42:53But extra weight is a liability. It makes it more difficult for the young to fly.

0:42:53 > 0:42:57The seas beside this South African colony are dangerous,

0:42:57 > 0:43:01 and not only because of the pounding surf.

0:43:07 > 0:43:12Had there been cliffs from which to launch themselves into the air,

0:43:12 > 0:43:18as there are around many gannet colonies, learning would be easier.

0:43:18 > 0:43:24But there aren't. No wonder they appear nervous about taking off.

0:43:27 > 0:43:30Fur seals are waiting.

0:45:06 > 0:45:08But in spite of the seals,

0:45:08 > 0:45:13 many young gannets do manage to get into the air.

0:45:18 > 0:45:22Flight for young birds is the essential skill.

0:45:22 > 0:45:27Failure can be fatal, so birds do all they can to prepare for it.

0:45:29 > 0:45:34The young open-billed storks, now fully grown,

0:45:34 > 0:45:39are strengthening their flight muscles with regular exercises.

0:45:50 > 0:45:54A young hummingbird cautiously practises hovering

0:45:54 > 0:45:58 while still in the nest,

0:45:58 > 0:46:02even though it makes life somewhat difficult for its sibling!

0:46:09 > 0:46:13On the tundra, the snowy owl chick,

0:46:13 > 0:46:18still semi-clothed in down, has got plenty of room for practice.

0:47:02 > 0:47:05And the surviving brown pelican

0:47:05 > 0:47:08at last leaves its platform nest.

0:47:10 > 0:47:16It joins other youngsters sitting at the edge of the sea.

0:47:16 > 0:47:21Each has already survived many perils in its young life.

0:47:21 > 0:47:26As a chick, it fought battles with its brothers and sisters and won.

0:47:26 > 0:47:31For nine or ten weeks, it was fed and protected by its parents.

0:47:31 > 0:47:34But now it's on its own.

0:47:34 > 0:47:37If it, in its turn, is to raise young,

0:47:37 > 0:47:43it has many more battles ahead of it out there on the sea and in the air.

0:47:55 > 0:47:58Life for all birds everywhere can be hard,

0:47:58 > 0:48:05but some species have become specially adapted to the harshest environments on earth.

0:48:05 > 0:48:09How they do so, you can see in the next programme,

0:48:09 > 0:48:14the last in this series about the life of birds.

0:48:40 > 0:48:44Subtitles by Lois Brooks BBC Scotland 1998