The Life of Birds (1998) s01e09 Episode Script

The Problems of Parenthood

For this brown pelican, the problems of bringing new life into the world have started even before the eggs have hatched.
They've had to be kept cool or warm, according to the time of day, and they've had to be defended.
But that is only the beginning of things.
0nce their chicks have disentangled themselves from their shells, the first job of these brown pelicans here in Florida, as it is with all bird parents, is to find food urgently.
Few are in a greater hurry than the Lapland bunting, for summer in the Arctic is desperately short.
Food is rushed in.
Droppings are ferried out.
Both parents labour tirelessly, and since it is light 24 hours a day at this time of the year, they do so non-stop.
As a consequence, the chicks grow at extraordinary speed, and only 12 days after hatching they will fledge.
Dippers are also dedicated and industrious parents.
A nest behind a waterfall is excellently concealed but tricky to visit.
Nonetheless, these dippers, between them, bring a batch of food to their young every ten minutes.
Gouldian finches in Australia make their nests in holes in trees.
The disadvantage of doing that is that it may be so gloomy within that it's difficult to see where the chicks are.
The solution? Vividly-coloured spots on the side of the mouth.
And when vibrations made by a parent as it enters tell these still-blind chicks that food is on the way, they quickly provide extra guidance.
With gapes patterned as vividly as this, the parents have no doubt about where to post their food parcels.
These are zebra finches.
And these extraordinary objects are young firetail finches.
What look like goggles are actually markers to indicate the corners of the mouth.
These are the chicks of Australian rosella parrots.
Their parents started incubating as soon as their first egg was laid.
That, therefore, was the first to hatch and its chick the first to be fed.
So to begin with, there is a difference in size between the chicks.
But rosella parents are scrupulously fair, and they make quite sure that even the youngest gets its proper share of food.
Even so, after ten days, the eldest is still the biggest.
But remarkably, it sometimes shares its food with the youngest and the smallest.
They are beginning to lose their down and proper feathers start showing through.
An itchy business apparently.
Three weeks later, in spite of five days' difference in age between the oldest and the youngest, they are all the same size.
Rosellas feed their chicks with a regurgitated porridge of chewed-up seeds.
Great-crested grebes, on the other hand, offer their newly-hatched young much stranger meals.
Feathers.
This is not a mistake or an occasional quirk.
Swallowing feathers is essential for the health of grebes.
They form a lining in the stomach which protects it from the sharp bones of the fish, which is the main part of a grebe's diet.
When the chicks grow up, they will swallow their own feathers, but now their parents obligingly provide them.
And that's just as well considering the size of the fish that the youngsters are prepared to tackle early on in their young lives.
These open-billed storks, nesting in the sweltering heat of Thailand, have also got young chicks.
0ne of their problems is keeping cool, and one of the ways of solving it, of course, is to take a nice cool shower.
But some showers are nicer than others.
The adults bring water back to the nest in their crops, and empty it over the featherless chicks.
But showers are not the only things that the chicks need.
Sitting virtually naked in the baking sun could be lethal During the hottest part of the day they are in desperate need of shade.
and the parents provide it.
The storks, like many birds, are exemplary parents, tending to the appetite and the comfort of their offspring with care and devotion.
But not all birds behave in such a way.
It's an idyllic scene - a pair of birds devotedly caring for their chicks in the springtime.
But for the adult birds, this is a very testing time, particularly if, like these coots, you may have as many as nine chicks and the food supply is far from certain.
Things start well enough.
0ne of the adults uses particles of food to tempt a newly-hatched chick down from the nest and on to the water.
The little flotilla sets off under the care of both parents.
But the food they prefer comes in very small instalments - tiny shrimps and water insects.
It takes a lot of collecting.
And there are other troubles and stresses.
Trespassers can't be allowed on to the coots' feeding grounds.
They have to be seen off, no matter how big they are.
Then, nearly always on the third day, the parents begin to lose patience.
A chick begs for food yet again .
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and is punished.
Each chick in turn gets this harsh treatment.
Maybe the adults are testing them to see which are the strongest.
After a time, they concentrate their punishment on one, and to such a degree that it stops begging and so starves to death.
But unless there is a superabundance of food, the persecution goes on.
In the end, the coots will only raise two or three out of their brood of nine.
Life for young pelicans can be equally brutal As they grow, so do their appetites.
No matter how hard the parents work, they cannot bring enough food for all three.
The last to hatch was always smaller than the other two.
It was always the last to be fed, and now the two older ones turn on it.
Now it will not survive.
Its parents will not bring any food to it on the ground.
And that's not the end of it.
No sooner has one been pushed out of the nest than a second will follow, until there is only one left.
And that's what happens nearly always in a pelican's nest.
That being the case, it seems rather inefficient, not to say heartless, that the pelican should always lay three eggs.
But the reason is that it's partly an insurance policy.
In case something terrible happens to one or two of the chicks, there's always a third left to carry on; and partly because, very rarely, when the fishing is very good, it is possible to raise more than one chick.
So bringing up the young is a very demanding business indeed.
And in most birds it requires the full-time labour of both male and female.
But one or two birds manage to avoid it altogether.
And one of them is a regular visitor to this reed bed in England.
A cuckoo, and she is raiding a reed warbler's nest.
That's one of the reed warbler's eggs gone.
And while she holds a second in her beak, shuddering with the effort, she lays one of her own.
The match is near perfect.
The cukoo's is the one at the front.
The reed warblers don't notice the difference and continue incubation.
The cukoo has timed her action with care.
She laid her egg immediately after the female reed warbler laid the last of hers, but it develops much faster and will hatch three or four days before the legitimate eggs do.
The young cuckoo, blind and naked, now deals with the remaining warbler eggs.
Two weeks later, the monstrous young cuckoo is so big that it can no longer fit inside the tiny nest.
Its brilliantly-coloured gape, together with its call, that mimics the sound of a brood of warbler chicks, constitute a demand for food that the warblers find irresistible.
The European cuckoo's habit is so famous that we tend to think it is the only bird to behave in this way.
But there are birds in half a dozen other families that do so as well.
Here in Argentina, brown-hooded gulls are nesting.
Gulls are so vigorous and enterprising that they might seem the last birds likely to be tricked, but on occasion they are.
A duckling.
Its true parents, cuckoo ducks, are far away from the nest where they dumped their egg.
Their offspring will never see them, just as they never saw their parents.
The duckling cannot know that it is quite different from the baby gull which has now hatched out alongside it.
Nonetheless, something tells it that it must not stay with this other nestling.
0n its very first evening, it leaves.
Unlike the cuckoo, it makes no further demands on the bird that incubated it.
Even though it is only a few hours old, it is perfectly capable of fending for itself.
Young goldeneyes also have a somewhat precipitate start to life.
The female goldeneye regularly lays in a woodpecker's hole.
But when her young have got over that handicap, she solicitously leads them down to water, for that's the only place where they, like most ducklings, can gather food for themselves.
Here in British Columbia, there is no shortage of lakes, and their mother goes ahead and calls to them to join her.
This lake, however, has already been claimed - by another female goldeneye with her brood.
And she is very possessive.
There's going to be trouble.
The newcomer has to leave.
But her ducklings can't fly away with her.
So they join the resident family.
That's no problem for mother.
They can fend for themselves.
And having an enlarged family reduces the chances of her own ducklings being taken by a hungry fish or a hawk.
In the end, she may accumulate a flock of twenty or more.
A river in the high Andes.
Unlikely though it may seem, some ducks manage to live on these racing waters as well - torrent ducks.
These have made their nest in the rocks thirty feet above the water, high enough to be safe if the river were suddenly to rise.
But that means that these ducklings also have a very hazardous journey to make.
Even mother has a little trouble.
The racing water might seem to pose even greater problems than the slippery rocks.
But the ducklings are so buoyant that they float on the surface, and are in no danger of drowning.
Nor are they swept away, for, miraculously, they know instinctively how to shelter in the eddies in the lee of a boulder.
And once launched, they, too, can feed for themselves.
Summer on the Arctic tundra.
Brent geese came up here a few weeks ago, to feed on the newly-sprouting vegetation and to nest.
Now their offspring have hatched.
They too will have to face a dangerous journey before they can feed.
This pair built their nest within a few yards of a snowy owl's nest.
That was good sense, for ground-nesting birds here are likely to be attacked by foxes.
0wls are quite prepared to tackle foxes.
And so they seldom venture near.
While they were incubating, the geese benefited greatly by nesting beside such a powerful neighbours, but now their eggs are hatching and that will change things.
0wls feed on lemmings.
And lemmings are about the same size as goslings.
Somehow, these little creatures will have to avoid becoming one more meal for a hungry owl But they must leave their nest if they are not to starve.
Their parents are well aware of the danger.
Equally, the male owl can see that there is a meal to be had.
Parental bravery wins the day.
Two birds to guard the young are good.
Three are even better.
Magpie geese live in northern Australia, and the journey their goslings have to make in order to feed is also dangerous.
Magpie males are very unusual in that normally they will mate with two females, who will both lay in the same nest.
So it is usually three adults, and only occasionally two, that escort their young.
In the skies above, a sea eagle.
It spots a trio with chicks .
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and they manage to see it off.
A pair are an easier target.
Angry and brave the two adults may be, but it's too late.
Attacks can come not only from the sky, but, more unexpectedly, from below.
Crocodiles.
Even the adults themselves are now in real danger.
And the goslings are very vulnerable indeed.
The pair have made it, but only two of their five young have survived.
The trio has succeded in bringing down four or five chicks.
Here in the feeding swamps, there is comparative safety.
All can join in keeping eagles away, and the water is too shallow for crocodiles.
Nonetheless, overall, the journey cost many young lives.
But the families that lost least were the trios.
So there really is safety in numbers.
And here in the Seychelles, numbers are astronomical - a million sooty terns.
Here, surely, there must be safety from predators.
But egrets stand around the fringes of the colony, and they will swiftly seize a chick if it's left unguarded.
A chick is such a good meal that the egrets will even risk stabs from the beak of a parent to get one.
Further into the colony, the chicks are surrounded by a great crowd of adults, and are very much safer.
Even a few yards from the edge, the egrets face such determined and effective opposition from all directions that they stand little chance of success.
Chicks that have the luck to hatch in the very centre are five times more likely to survive than those on the edge.
And there's another way for a bird to protect its chicks.
Rear them in a place so remote that few other creatures can get there to threaten them - a place like the Australian desert.
Here banded stilts nested beside a temporary lake.
Soon after their eggs hatched, the females left and started nesting again elsewhere.
Now the youngsters have gathered in groups several hundred strong, with only just a few males left behind to keep an eye on them.
The job is not too difficult, for the salty waters are full of tiny shrimps that the young stilts can collect for themselves.
For other birds, however, finding food is so difficult that even two parents can't feed their chicks unaided.
Farther south in Australia, in the eucalyptus woodland, white-winged choughs have that problem.
Their young feed on beetle grubs, and those are so difficult to excavate that a pair will need at least two adult helpers to keep one chick fully fed.
And the more helpers they have, the more chicks they can raise.
This chick is almost fully grown and so has a very big appetite.
All four birds labour away to keep it supplied.
Eventually, however, it will change from being a liability into an asset, a young bird that can help in rearing a chick next year.
Another group of choughs appears in the trees.
It has many more members.
The residents are worried, and show their agitation by goggling their eyes.
This is a press gang.
They are kidnappers.
And this is what they are after.
0ne of the raiders starts to display to the chick, trying to entice it away from its parental group.
And it follows.
A kidnapping has been achieved.
The raiders feed their new recruit, and it joins the group's own youngster.
Now they have two juveniles.
Next year, the support team will be so big that they may be able to raise three or even four chicks.
So having difficulties in raising baby can lead to sociability among adults.
But perhaps the most sociable of all birds, birds that behave almost like a troop of little monkeys, live here in the deserts of the Middle East.
An Arabian babbler.
But you hardly ever see just one.
Arabian babblers do everything together if they possibly can, and that certainly includes taking a bath.
After a bath, the whole group sunbathe together.
0nce dry, they preen each other.
In fact, Arabian babblers do most things as a group.
They all share the labour of collecting food for the group's chicks.
They also share the responsibilities for defence, taking it in turn to act as sentry.
When another sentry comes on duty, it brings a morsel of food as part of the hand-over ritual A viper! The sentry sounds the alarm.
The whole group assembles.
By creating a commotion, they ensure that everyone is aware of the danger.
They also discomfort the snake and perhaps distract it from hunting.
It may also be that some of them, by deliberately taunting the snake at close quarters, are demonstrating their strength and fitness in a way that will give them respect and seniority within the group.
0nce the danger is past, life returns to normal The sentry goes back to guard duties, and the youngsters start to play among themselves.
Many young birds are abandoned by their parents almost as soon as they are capable of flight, so they have little chance to play and gain the skills they will need as adults.
But the babblers form such a coherent group that the juveniles can spend time doing just that.
For the young anhingha in Florida, learning through play is essential If it doesn't become a skilled juggler quickly, it will starve.
It must learn to do this.
0f course, it is important when playing with a stick not to take the game too far.
Gannets also fish by diving, and that is a skill that can't be practiced by the young until they can fly.
The parents deal with this problem by feeding their young so generously that, by the time they've fledged into their dark immature plumage, they've accumulated reserves of fat that will sustain them while they are learning to catch fish for themselves.
So now they are heavier than their parents.
But that extra weight is a liability.
It makes it more difficult for the young to fly.
The seas beside this South African colony are dangerous, and not only because of the pounding surf.
Had there been cliffs from which to launch themselves into the air, as there are around many gannet colonies, their first flight would be easier.
But there aren't.
No wonder they appear nervous about taking off.
Fur seals are waiting.
But in spite of the seals, many young gannets do manage to get into the air.
Flight for young birds is the essential skill, and the penalties of failure can be fatal, so birds do all they can to prepare for it.
The young open-bill storks, now fully grown, are strengthening their flight muscles with regular exercises.
A young hummingbird cautiously practices hovering while still in the nest, even though that makes life somewhat difficult for its sibling.
0n the tundra, the snowy owl chick, still semi-clothed in down, has got plenty of room for practice.
And the surviving brown pelican at last leaves its platform nest.
It joins other youngsters sitting at the edge of the sea.
Each has already survived many perils in its young life.
As a chick, it fought battles with its brothers and sisters and won.
For nine or ten weeks, it was devotedly fed and protected by its parents, but now it's on its own.
If it in its turn is to raise young, it has many more battles ahead of it out there on the sea and in the air.
Life for all birds everywhere can be hard, but some species have become specially adapted to the harshest environments on Earth.
How they do so you can see in the next programme, the last in this series about The Life of Birds.