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04:29The sea brings them together, keeps the fertilized eggs at the near-stable temperature necessary for development,
04:36and transports them for hundreds of miles to new environments.
04:43This perpetually renewed soup provides a vast banquet for other floating creatures.
04:50Small, complex globes of jelly drive themselves through the water with lines of beating hairs and filter out the majority of the eggs.
04:59The sea brings them together, keeps the eagle porungs Kisses단 socials andijins shots and Kumagaiidos.
05:06The sea brings the plant bens to ю setting agency� ê o
05:23Many fish also scatter their eggs in the water
05:38and abandon them in a similar way.
05:41But the most stupendous egg producer of all lies beneath,
05:46nearly buried in the reef.
05:49The giant clam first discharges sperm.
05:53And then half an hour later, because it's both male and female, eggs.
06:00In each annual spasm, it discharges 1,000 million.
06:04In the northeastern Pacific, vast shoals of herring are moving towards the coast of Alaska.
06:26MUSIC CONTINUES
06:33These must be the densest concentrations of animal bodies to be found anywhere in the world.
06:46Throughout their lives, they move in huge assemblies, millions strong,
06:50sieving their floating food from the ocean waters.
06:53Now, even more tightly packed together, they start to spawn.
06:57MUSIC CONTINUES
07:04Their eggs are sticky and cover the leaves of the sea plants.
07:12MUSIC CONTINUES
07:14As the waves stir the waters,
07:41some of the vast deposit floats up to the surface.
07:46These milky slicks, miles long, stretching around the coast,
07:50may look like mud washed into the sea by a great river.
07:54But they're made up of nothing but eggs and milt,
07:57the annual legacy of the departed herring shoals.
08:01MUSIC CONTINUES
08:03Many of the eggs are washed ashore,
08:18and the receding tide leaves them stranded on the rocks like drifts of snow.
08:25And this provides a feast for birds.
08:30Gulls gorge on them.
08:32MUSIC CONTINUES
08:34A thousand upon thousand of turnstones, sandpipers,
08:53and other small waders also come.
08:56For them, this bonanza could not be better timed,
08:59for they're about to set off on their spring migration,
09:02and they need to stock up with fuel
09:04before starting on their long flight.
09:07MUSIC CONTINUES
09:09It's effective to lay vast numbers of eggs
09:26when there's water to distribute them.
09:28On land, however, such numbers would be less practical.
09:31Even so, some land animals produce them in hundreds.
09:37These are young mantis.
09:39Their mother surrounded her batch of eggs
09:41with a liquid froth which rapidly hardened.
09:45The young developed within,
09:46and now they're ready for independent life.
09:49MUSIC CONTINUES
09:49Their infant bodies are covered with a thin membrane,
09:56and each hangs suspended by a thread of silk
09:58while it slowly disentangles itself.
10:02One egg mass produced by a single female
10:06may release as many as 400 young.
10:11MUSIC CONTINUES
10:12While latecomers continue to emerge,
10:21the firstborn clamber up over them
10:23and prepare themselves for adult life.
10:25MUSIC CONTINUES
10:26FROGS
10:26Frogs produce young that swim and breathe through gills,
10:40tadpoles.
10:40So most frogs lay their eggs in ponds and streams,
10:44but not all.
10:46This Trinidad tree frog
10:47creates its own watery nursery up in a tree
10:50where there are no predatory fish
10:52to worry them or their babies.
10:56The female pulls two leaves together with her hind legs
10:59and extrudes her eggs into the space between them.
11:04MUSIC CONTINUES
11:04The eggs are surrounded by a sticky jelly
11:12which holds the leaves together.
11:14As they emerge from her body,
11:16so the male on her back discharges his sperm
11:19and fertilises them.
11:20MUSIC CONTINUES
11:20Over the next eight days,
11:36the eggs slowly turn into tadpoles.
11:40Once the first eggs hatch,
11:42the jelly begins to dissolve,
11:44the leaves separate,
11:45and the liquid within starts to trickle out.
11:52And with it come the tadpoles.
11:59But this is no disaster.
12:01The tadpoles drop into a new existence,
12:04for happily,
12:05their parents always build the nurseries
12:07from leaves that overhang water.
12:08MUSIC CONTINUES
12:09Here, in a bigger world,
12:23they can find something to eat
12:24and start to build their adult bodies.
12:30This South American rainfrog
12:32is totally independent of pools and rivers.
12:35It lays its eggs on the ground.
12:37But each small globe is full of liquid.
12:41The tadpole not only develops inside this capsule,
12:44but stays there,
12:46swimming in its own personal pond,
12:48until tadpole becomes frog.
12:50MUSIC CONTINUES
12:52...
13:14MUSIC CONTINUES
13:18When the young finally emerge, they have no need to swim.
13:41Like their parents, they have lungs and legs.
13:48These elegant eggs are only the size of grains of sand.
14:15The young of the owl butterfly.
14:18Their beautiful shells are not just protective, they're edible.
14:27The mother butterfly built them from her bodily reserves of protein.
14:30So her young, when they emerge, have their first meal immediately to hand.
14:35There's another way of providing food for your developing young.
14:49Instead of getting it from your own body, you can get it from somebody else's.
15:03That, of course, involves the grisly process of body snatching.
15:09And that's just what's going on in this dried up mud flat in the western United States.
15:14This strange insect is a murderous and very hard-working wasp.
15:21She is digging a tunnel to serve as her nursery.
15:28The sun-baked ground she selects is rock-hard, and digging a hole in it is not easy.
15:35A lot of work is invested in one of these holes, and if one seems vacant, another wasp will try to claim it.
15:54Once the burrow is finished, the female performs an elaborate dance around it, familiarising herself with its surroundings, so that she knows exactly where it is.
16:07And then she conceals it, so that none but she is likely to find it.
16:24Her nursery must now be provisioned, and for that she needs fresh meat, a caterpillar.
16:33First, she paralyses it with her sting.
16:41Thanks to her dance, she knows exactly where her hidden hole lies.
16:54Each burrow will have several caterpillars in it, and each addition requires the same stopping and unstopping of the tunnel entrance.
17:03The urge to collect caterpillars is so strong that they'll pick them up wherever they find them.
17:15Watch this.
17:16She has already laid a long yellow egg on the first caterpillar.
17:28When the tunnel is full, she seals it with special care.
17:34She uses a grain of gravel like a pneumatic ram, vibrating it by buzzing her wing muscles, one of the few instances of an insect using a tool.
17:55In a few days' time, when the egg hatches, the grub will find fresh meat awaiting it.
18:04These cabbage white caterpillars are also doomed.
18:09Another species of wasp injects them, not with paralysing poison, but with eggs.
18:16Day after day, the caterpillars grow and mature, apparently unaffected.
18:36But inside them, the wasp eggs are developing.
18:40Day after day after day.
19:09Having fed so richly on the entrails of their caterpillar host,
19:13the wasp grubs are ready to pupate as soon as they emerge,
19:18and they start straight away to spin their silken cocoons.
19:26Ten days later, they have become adult wasps
19:29and are themselves starting to search for caterpillars.
19:33Just where eggs are placed can be very important.
19:39These mosquitoes in Trinidad deposit theirs on the surface of water,
19:43where they float like rafts.
19:50The females signal with their legs,
19:52perhaps warning other flying females that this place is already taken.
20:03They lay in tiny pools of standing water and particularly favour nutshells.
20:21Heavy raindrops might sink the tiny rafts,
20:24so if there is a shower, the adults row the eggs to shelter.
20:28When the young hatch, they drop from the bottom of the raft
20:33and swim down to start collecting food.
20:47These fish also care for their eggs with great solicitude.
20:51They are Midas cichlids from Nicaragua.
20:55Once a pair has selected their territory,
20:57the male digs a small pit in the ground.
21:15The golden-coloured female, meanwhile,
21:17has meticulously cleaned the surface of a rock with her mouth,
21:21and now she's moving slowly over it,
21:23laying lines of sticky eggs.
21:27As she completes each pass,
21:29the male follows behind and discharges his sperm.
21:32Within an hour, there are as many as 2,000 fertilised eggs on the rock wall.
21:49Three days later, they begin to hatch.
22:03The female gently picks off the wriggling young.
22:07In they go, into the cradle that the male dug for them,
22:18even before they were spawned.
22:20They have a sticky pad on their heads that enables them to stay attached to the gravel.
22:39They can hardly yet be called fish.
22:41They have no mouths, and they nourish themselves from a speck of yolk within their body
22:46that is bigger than they are.
22:48As they wriggle, they create a current that brings them oxygen.
22:53Their eyes have now developed,
22:55and much of their yolk has been used up in building their growing bodies.
22:58And all the time, their parents remain above them,
23:15to defend them against anything that might make a meal of them.
23:21Now their yolk is almost gone,
23:23and they must sustain themselves in a different way.
23:26Five days after becoming free-swimming,
23:29they start to graze over the bodies of their parents.
23:32The adults are producing a nutritious slime from their skins,
23:36so their cloud of babies can find food without straying too far away.
23:58Many parents put their own personal safety at risk.
24:02in order to protect their eggs.
24:04In Brazil, a sawfly crouches over her eggs for three long weeks,
24:10threatening any intruder with an aggressive buzz,
24:13flicking her wings with which she will strike if necessary,
24:17and displaying her formidable jaws.
24:23Even an assassin bug knows when it's met its match.
24:32As a result of her dedication,
24:3490% of her eggs survive to hatch.
24:38Even then, she won't desert.
24:41She stays with her caterpillars to protect them.
24:44But a single guard can't be everywhere at the same time.
24:48So her young, instead of scattering to feed, remain together.
24:52So her young, instead of trying to feed, remain together.
25:13Bigger parents have similar problems.
25:16Snow geese in the Russian Arctic have to be just as vigilant if they are to rear their babies.
25:29Eggs packed with yolk are splendid food and tempt a lot of thieves.
25:40For Arctic foxes, this is a time of plenty.
25:43Hundreds of eggs are lying around on the cold tundra, but they're all defended.
26:13Eggs and eggs are already dead.
26:18Good job.
26:18What does this mean?
26:20Canopy andhma fish get out.
26:22If the egg is still in the frozen egg, if they are completely different, you can see the egg.
26:26The egg is just right.
26:29The egg is just right.
26:30It looks like the egg is done.
26:31It looks like the egg is just right now.
26:33The egg is just right now.
26:34I'm not sure?
26:34We're just very good.
26:35It looks like the egg is just right now.
26:36I've got the egg is just right.
26:37Yes, they are just right here with their egg.
26:37It looks like it is.
26:38Got one.
27:01But why doesn't it eat it?
27:08This glut of eggs won't be here for long.
27:13With so many around, it's better to hide away the swag to be eaten later and go back for more.
27:19In the cold, near-freezing earth, an egg will remain fresh and edible for a long time.
27:28Those still in the nest, however, kept warm by their parents, are beginning the universal process that is still one of the most mysterious events in life.
27:38The greater part of a bird's egg, the yolk, is food for the developing young.
27:44On its surface, beneath the cushion of clear albumen, lies just one fertile cell.
27:50In the sustained warmth, it grows, divides and grows again.
27:54Within two days, a beating heart has appeared.
27:59Blood vessels spread around the yolk, collecting its nourishment and transporting it to the growing embryo.
28:0512 days later, the little creature has legs.
28:21And beneath the tracery of blood vessels, the tiny head is virtually complete.
28:2615 days, and feathers are beginning to sprout.
28:4121 days after incubation started, the moment for hatching has arrived.
28:5321 days after the
29:05degress of the priest bone has työ conditionneds.
29:0922 days after the
29:23Once dried, the downy feathers help the tiny body to retain its warmth.
29:43The chick is ready to start a new stage in its life.
29:53There are few more formidable mothers than this one.
29:59The saltwater crocodile of northern Australia builds her nest on the leaf-strewn bank of a river.
30:18She digs a deep hole in the peaty soil.
30:23In it, she lays several dozen eggs.
30:35These eggs have one strange characteristic.
30:39Even though they have left her body, the sex of the babies within them is not yet fixed.
30:45It will depend on how she looks after them.
30:54She covers them with dead leaves, which, as they decay, will produce the heat the eggs need in order to develop.
31:02And it is this that determines the sex of the babies.
31:12At 30 degrees centigrade, they will all be female.
31:19Two degrees higher, and they will be all male.
31:22In between, they will be exactly half and half.
31:26If the nest temperature rises two degrees higher still, then a third of the eggs will be male, a third female, and a third will die.
31:35Their emergence is less arduous than that of a baby bird, for reptilian shells are leathery and easily broken.
31:45The babies are so well-formed that even before they leave the shell, they can bite.
32:02The technique of warming eggs with rotting leaves has been brought to a fine art by the Malleyfowl of southern Australia.
32:20A pair build themselves a huge mound of sand. In its heart lies a layer of leaves.
32:29Every few days throughout the breeding season, the female comes to lay, and the male kicks away sand to expose that layer.
32:37Her egg, compared with her body, is gigantic, and as soon as she's produced it, the male covers it over.
32:49Now the temperature must be carefully monitored. The male measures it with his beak.
32:58Even when visitors approach, he stays bravely beside the mound to keep an eye on things.
33:04If the mound is too cold, he piles sand on top. If it's too hot, he kicks it away.
33:14So obsessed is he with managing this mound, that if someone interferes with it, his first instinct is to put that right.
33:27If I flick sand off, he flicks it back.
33:34It's a great place.
33:35They're not easy to see the mound.
33:36The chick has to dig its own way up through the sand.
33:39It's able to do something with the fridge and it's a fork.
33:40The chick has to dig its own way up through the sand.
33:56It's able to do something with the grass being a fool or something.
34:00has to dig its own way up through the sand.
34:03It's able to do so because that huge egg contained so much yolk
34:07that the chick could stay in it gathering strength for 49 days.
34:12It'll be able to fly within 24 hours.
34:17In the trees above, there are chicks
34:20that are having a much harder, hungrier time.
34:24The crested hawks laid three eggs each a day apart,
34:28but they started incubation when the first arrived.
34:32So the first laid was the first to hatch,
34:35and that chick was the first to get a meal.
34:38With such a start, it's already bigger than the two younger ones.
34:43The parents work hard, bringing food.
34:46But the eldest chick nearly always gets it.
35:01To him that hath, it shall be given.
35:03The youngest, the smallest,
35:10stands little chance of a mouthful
35:12as long as either of the bigger ones are in the least hungry.
35:23Once again, the youngest gets nothing.
35:26And now, it's dead.
35:43This was a gamble by the adults.
35:46Had it been a specially good year,
35:47then they would have been ready to take advantage of it
35:50and rear three chicks.
35:52But this year, as in most years,
35:54the gamble didn't pay off.
36:09The little body is not totally wasted.
36:13Some of its flesh is fed to the survivors.
36:16Animals care for their eggs and young in many different ways.
36:38But Peripetus, a curious creature, half worm, half centipede,
36:42provides the ultimate in parental protection.
36:45The eggs develop inside the female
36:48and she keeps them there until they're so advanced
36:51that they can survive without the protection of a shell.
36:53And now, we're going to take advantage of it.
36:56And now, we're going to take advantage of it.
36:57And now, we're going to take advantage of it.
36:58And now, we're going to take advantage of it.
36:59And now, we're going to take advantage of it.
37:00And now, we're going to take advantage of it.
37:01And now, we're going to take advantage of it.
37:02And now, we're going to take advantage of it.
37:03And now, we're going to take advantage of it.
37:04And now, we're going to take advantage of it.
37:05And now, we're going to take advantage of it.
37:06And now, we're going to take advantage of it.
37:07And now, we're going to take advantage of it.
37:08And now, we're going to take advantage of it.
37:09And now, we're going to take advantage of it.
37:10So the young Peripetus gets a good start in life.
37:35No waiting around, defenceless, imprisoned in an egg.
37:38It's able to feed and hide itself just as soon as it leaves mother.
37:44All kinds of creatures have, independently, adopted this strategy.
37:50The tsetse fly.
37:52The bigger the young, the fewer a female can produce.
37:56And the tsetse fly's baby is a wapile.
38:08In the whole of her six-month life, she can only give birth to a dozen of these plump grubs.
38:20It crawls away to turn into a pupa, from which the adult fly will quickly emerge.
38:26These baby beetles are also long past the egg stage.
38:32Their transformation into an adult will also take place inside the protective shell of a pupa,
38:38but meanwhile, they work as small eating machines, gathering the food necessary to construct an adult body.
38:57But these gnat grubs avoid the pupal stage altogether.
39:01They feed on mushrooms, which disappear after a few days.
39:05So the grubs must eat all they can while they have the chance.
39:09To do that, they reproduce even before they become adult.
39:13The unfertilized eggs of the female grub begin to develop within her body.
39:18They feed by browsing on their mother's internal organs,
39:22so that eventually she herself is reduced by her own young to a sausage skin,
39:28through which 30 or so grubs force their way, coming out at both ends.
39:33Each is a clone, genetically identical with its single parent,
39:39and each of these 30 can do the same trick in six days' time.
39:43In six weeks, if there were enough mushrooms, there could be 20,000 million, all identical.
39:51Her mother's sea louse, a kind of crustacean, also commits suicide in order to launch the next generation.
39:58The mass of babies within her tiny shell have consumed so much of her energies,
40:05that as the last leaves, she, exhausted, will die.
40:18It's not only females that can give birth.
40:21A few exceptional males also get pregnant.
40:25The male pipefish develops a sticky underside on which the female deposits her eggs.
40:31Flaps of skin grow round them,
40:34and when the time comes, the young wriggle out to take their chances in a dangerous world.
40:39or, with the Book Probeys, the World of Skyhands have been Andy before her şeker,
40:41but the family's most thankful for the earth.
40:42Thank you very much for the Ekente xi to see
40:55his head for being the show,
40:58with his reason why he's still alive.
41:00And he returns in their filled form ofulas concerned
41:02the Horsesies,.
41:03And, they prevent themselves from hombre's question
41:05that it becomes obvious.
41:06Once they leave the protection of their father's body,
41:09they're easily picked off by hungry sticklebacks.
41:16But the babies who remain within their mother's body for the longest time,
41:20and who are cared for in the most comprehensive way of all,
41:23are those of mammals.
41:25These female sea lions mated a year ago.
41:29The fertilised egg fixed itself to the womb wall,
41:33tapped the mother's blood supply and grew month after month.
41:37Now that long development is over,
41:39and the labour of entering the outside world has begun.
41:57The membranes that held the fluid within which the infant swam
42:00while it was within its mother's body
42:02still partially enclose it.
42:32For all mammal babies,
42:37the shock of leaving the warm, totally protected haven of a mother's body,
42:41and entering the harsh, relatively cold, danger-filled world outside,
42:47is inevitably traumatic.
42:49The baby antelopes, whose parents have to travel continuously to find food,
43:00must be as fully developed as possible,
43:03for they need to walk within hours, groggy though they may be.
43:07Chinchillas are born in the high Andes.
43:22Their world is a very cold one.
43:35Their mothers make no nests for them,
43:37so they are born fully furred.
43:40Were they not, they might freeze to death.
43:43Hyena babies need not be so advanced,
43:58for they're born within a den,
44:13where their powerful mother has little difficulty in defending them.
44:17So she can get rid of their bulk and weight
44:19while they're still at an early stage of their development.
44:23As soon as they emerge, like all young mammals,
44:26they must find their mother's teat and start to suckle.
44:30Perhaps the trickiest mammal birth of all is that of the bat,
44:50for it, after all, has to arrive in this world
44:53while its mother hangs upside down from the ceiling.
45:00Whatever happens, the baby mustn't fall.
45:04While mother hangs acrobatically from one leg,
45:07she stretches out the other
45:09so that the web connecting it to the tail
45:11forms a cradle in which to catch her newborn babe.
45:26One infant is all that a mother bat of this species
45:29can produce at one time.
45:31Her mammalian nature dictates that she keeps it within her body
45:34until it's well developed,
45:36and even one is a very heavy load when flying.
45:39Now she feeds it from her own body with that special food, milk,
45:44which is all that a newly born mammal can digest.
45:47The arrival in the world of this single baby,
45:50so tenderly nurtured by its mother,
45:52could hardly be more different from that of so many creatures that live in the sea.
46:02Birth for the Christmas Island crabs is a comparatively protracted affair.
46:07For 28 days they float helplessly in the sea,
46:10slowly increasing the size and complexity of their body,
46:14until at last they are just recognisable as miniature crabs.
46:18But very few of them live as long as that.
46:21Fish eat them in huge quantities,
46:23currents sweep them away into the open ocean.
46:26So that for most years,
46:28the entire spawning of billions is totally lost.
46:32But almost miraculously, about one year in five,
46:36a few hundred thousand appear in the waves off the coasts
46:40where they first fell into the water as eggs.
46:43And then these little creatures, no bigger than ants,
46:46valiantly struggle ashore.
46:49A single female crab during her lifetime may produce a million eggs.
46:54If just one survives,
46:56then she may be just as successful as a bat, a sea lion,
47:00or any other creature that each year lavishes its care on a single baby.
47:05So, in a multitude of different ways,
47:10new lives appear on Earth.
47:13And each starts off on its own individual odyssey.
47:16They've survived the first of their trials,
47:19but they'll have to face many more before, in turn,
47:23they too will have a chance to give birth.
47:35This is where robots are corrupted,
47:37now we know that they've即 Ned got pretty dark but they're causing
47:39fires in change.
47:40And now,
47:43the theme of the creatures,
47:45these two really decks of nature are realidade and dampened.
47:49That way about whateness has been great,
47:51for us?
47:52No one?
47:53The purpose of space is here.
47:54The purpose of space is it in fact that we're gonna have to
47:56put together it Board of Water for the particular
47:58그 reader's temporower in the air.
47:59The purpose of space is to go off the queue.
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