BBC's Life of Birds
Approximately 580 minutes
3 Discs
From BBC Video: EPISODE 8: THE DEMANDS OF THE EGG - "Sooty terns are amongst the most aerial of birds.They spend the first three or four years of their lives flying non-stop - feeding by snatching food from the surface of the sea, even sleeping on the wing, But there is one thing that forces them down to land - to lay their eggs."
Because birds need to be light in order to fly, each egg must be laid as soon as it is produced and then kept both warm and protected.So the vast majority of birds make nests of some kind.Some birds still just dump their eggs on the ground, others lay them on bare branches and a few even nest behind waterfalls. Australian warblers use their beaks like a sewing machine to stitch leaves together, and apostle birds use them to trowel mud on their nests. Palm swifts rely on no more than spit and feathers to keep their eggs safely suspended on vertical leaves, while in Argentina there are parrots which burrow in to sheer cliffs. The female hornbill seals herself within a tree hole and is totally dependent on her mate to feed her for the four months until the chicks are well grown. A kiwi laying an egg really brings tears to the eyes - the egg is a quarter of the bird's body weight,making it the biggest relative to body size produced by any bird. An X-ray view proves just how big the egg is inside the body.
The little Australian thornbill makes a dummy nest on top of the real one just to confuse its enemies.A passing predatory cur rawong sees an apparently empty cup and flies by, leaving the parent to sneak back in through a hidden entrance. "There really is sense in not putting all your eggs in one basket." Redheaded ducks take out insurance policies by laying some eggs in other ducks'nests as well as using their own.But what has never been seen before is how the intruder simply pushes aside the resident duck in order to lay an egg in her nest. If a raccoon then destroys the intruder's own nest a duckling or two may still survive in someone else's nest. In South Africa, weavers defend their nests against cuckoo attack either by building long narrow entrance tubes in which the cuckoos get stuck or by producing many different egg colours to confuse the enemy. As the weaver eggs can range from blue to white and from plain to speckled the cuckoo's chances of getting a perfect match in a particular nest are narrow. If they do try, the weaver quickly identifies the 'odd'egg, and chucks it out.
EPISODE 9: THE PROBLEMS OF PARENTHOOD - "Model parents feed their youngsters feathers to aid digestion,sprinkle water over them and shade them from the sun.There are goose parents who take on snowy owls and sea eagles in defence of their precious goslings. But there are also dangers for the young much closer to home. Brothers and sisters fight for supremacy in the nest where there will be only one survivor. And there are coot parents that are forced to identify their weakest young and kill them."
Parents may have to keep their chicks warm or cool, fed and healthy for months before they fly the nest.The first thing any chick needs is food, and finches have an extraordinary array of "Feed Me" signs around their beaks - from luminous nodules to black and yellow beak markings and striped tongues. The first meal a great-crested grebe chick gets isn't a fish but a feather. Feathers are gently offered until they line the chick's stomach and so aid the later digestion of bony fish. Storks give their young cooling showers in the midday heat by spitting water over them,and David Attenborough gets caught in the downpour. Then the birds spread their wings over the chicks like parasols to provide welcome shade. On village ponds throughout Britain,child abuse and even infanticide is being committed as coots turn on their young. When food is short, parents may resort to pecking their chicks on the head to sort out the weak from the strong. After sustained battering, the weaker chicks stop begging for food and starve to death.
Other parents will risk their own lives to save their family. Brent geese nest close to snowy owls on the Arctic tundra, and so gain extra protection from foxes.But when the time comes for the goslings to leave the nest to make the trek to water the owls turn on them. Only the determined counterattacks by both parents ensure that the family reach safety. David Attenborough describes Arabian babblers as, "the most sociable of all birds, birds that behave almost like a troop of little monkeys." They bathe in a bath provided by Attenborough and then huddle and preen together. One acts as sentinel while the young birds rough and tumble like puppies.The whole group responds to an alarm call and mobs a snake - holding their wings up and dancing round it like matadors round a bull. At the other extreme, a young cuckoo duck never even sees its parents. It hatches where it was laid on a gull's nest and at the end of its first day quietly slips away to make its way in the world entirely alone.
EPISODE 10: THE LIMITS OF ENDURANCE - "There is scarcely a corner of the globe that birds have not colonised.Where there is food,there will be some species of bird that has solved the problem of collecting it and of enduring the penalties of living close enough to do so."
In the Arabian desert, crab plovers endure temperatures above 40ºC. An egg would normally fry if left on such a boiling hot surface, so unlike any other wading bird in the world, the crab plover digs tunnels deep in the sand and lays its eggs away from the scorching sun. Lesser flamingos tolerate crippling heat as they stand in corrosive African soda lakes: "The fact that so few creatures can tolerate these conditions means that any animal that can, has the place to itself and so can proliferate in vast numbers." At another extreme, camerawoman Justine Evans filmed David Attenborough among a 10,000-strong nesting colony of oilbirds in a pitch-black cave in Venezuela.T he birds navigate in the dark using sonar and share the cave with vampire bats, rats, and crabs. Many birds have been brought to extinction by human activities, but some happily take advantage of people. Black vultures nest on the ledges of skyscrapers in the concrete city of San Paulo, Brazil - one pair setting up home on the 16th floor of a glass-and-steel office block. They find an endless supply of food by scavenging on the waste tips on the edge of the city. "Not many birds have either the temperament to tolerate such places or the digestion to cope with such food. But those that have swarm in huge numbers."
Carrion crows have learned to crack walnuts on concrete roads in Japan. If that doesn't work the crows drop the nuts on a zebra crossing when the traffic lights are on red, wait for the lights to change and the vehicles to run over their nuts. They even have time to stroll across the road when the traffic stops again and eat their treat! Humans can do a lot to help birds. In Spring, more than a million North American householders eagerly await the arrival of purple martins and string up wonderful nesting boxes for them. In Arizona,retired Jesse Hendrix spends all day filling bird feeders with sugar water for the thousands of migrating hummingbirds that pass through his garden each year. During the busiest migratory period, in a single day he can be visited by 9,000 hummingbirds. Every year, more than 500,000 people from all over the world, visit Phillip Island near Melbourne to witness one of Australia's most popular tourist attractions: 1,000 little penguins' dusk march up the beach to their traditional nesting burrows. David Attenborough visits the International Crane Foundation in Wisconsin to feed atwo-day-old whooping crane, one of the rarest birds in the world. The bird isn't allowed to see human beings in case it becomes imprinted, so a specially modelled hand-glove puppet holding the food is put through a small hole in the door. Kent Clegg, a farmer in Idaho, teaches whooping cranes to migrate. First they follow Kent and his bike around the farm, and then they follow his microlite plane, in preparation for the 750-mile migration down to New Mexico.
