the-french-artist/wikipedia_20220301.simple_sentence_split huggingface dataset:
They communicate with visual signals, calls and bird songs.
Most of their social behaviours are inherited, such as cooperative breeding and hunting, flocking and mobbing of predators.
Most bird species are socially monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life.
Other species are polygynous (one male with many females) or, rarely, polyandrous (one female with many males).
Birds produce offspring by laying eggs which are fertilised by sexual reproduction.
They are often laid in a nest and incubated by the parents.
Most birds have an extended period of parental care after hatching.
Some birds, such as hens, lay eggs even when not fertilised, though unfertilised eggs do not produce offspring.
Many species of birds are eaten by humans.
Domesticated and undomesticated birds are sources of eggs, meat, and feathers.
In English, domesticated birds are often called poultry, undomesticated birds are called game.
Songbirds, parrots and other species are popular as pets.
Guano, which is bird manure, is harvested for use as a fertiliser.
Birds figure throughout human culture.
About 120–130 species have become extinct due to human activity since the 17th century and hundreds more before then.
Human activity threatens about 1,200 bird species with extinction, though efforts are underway to protect them.
Recreational bird-watching is an important part of the ecotourism industry.
Bird colours
Birds come in a huge range of colours.
These colours can be useful to a bird in two ways.
Camouflage colours help to hide the bird, and bright colours identify the bird to others of the same species.
Often the male is brightly coloured while the female is camouflaged.
The logic is as follows: the female carries the "precious package" of developing eggs.
The male has to defend a territory, and the function of his colour and song is to let others know that "this place is occupied".
Bird camouflage
Many birds are brown, green or grey.
These colours make a bird harder to be seen: they camouflage the bird.
Brown is the most common colour.
Brown birds include: sparrows, emus, thrushes, larks, eagles and falcons and the female birds of many species such as: wrens, ducks, blackbirds and peafowls.
When a brown bird is in long grass or among tree trunks or rocks, it is camouflaged.
Birds that live in long grass often have brown feathers streaked with black which looks like shadows.
A bittern is almost invisible in long reeds because its camouflage is helped by its posture (beak and head pointed upwards).
Other birds, including starlings and mynas, are quite dark in colour, but are flecked with little spots that look like raindrops on leaves.
Bird may also camouflage their nests.
Many birds from hot countries are green or have some green feathers, particularly parrots.
Birds that live in green trees often have green backs, even if they have bright-coloured breasts.
From the back, the birds are camouflaged.
This is very useful when sitting on a nest.
The bird's bright-coloured breast is hidden.
Budgerigars are bred in different colours such as blue, white and mauve, but in the wild, they are nearly all green and yellow.
Even though they fly very well, they normally spend a lot of time on the ground, eating grass seeds.
Their yellow and black striped back helps to hide them in the shadows made by long dry grass, while their green breasts are a similar colour to the leaves of gum trees.
Grey birds include most pigeons and doves, cranes, storks and herons.
Grey birds are often rock-living birds like pigeons or birds that sit on dead tree trunks looking like a broken branch.
Water birds like herons often have a pale grey colour which makes it harder for a fish to notice that the bird is standing, looking down for something to catch.
Water birds, no matter what colour they are on top, are often white underneath, so that when a fish looks up, the bird looks like part of the sky.
Black birds include crows, ravens and male blackbirds.
Some birds that are dark colours spend quite a lot of time on the ground, hopping around in the shadows under bushes.
Among these birds are the male blackbird and the satin bowerbird which is not black but very dark blue.
Crows and ravens often perch high on bare trees in the winter, where their black shape against the sky looks like the dark bare branches.
Noticeable colours
Many birds are not camouflaged, but stand out with vivid colours.
They are usually male birds whose females are dull and camouflaged.
The function of the colours is two-fold.
First, the colours help them get mates, and second, the colours identify them to other males of the same species.
Many birds are territorial, especially in the nesting season.
They give out territory sounds and are easily seen.
This lets other males know they will defend their territory.
It sends out a "look elsewhere" signal to their competitors.
Many other birds are very brightly coloured, in countless combinations.
Some of the most colourful birds are quite common, like pheasants, peacocks, domestic fowl and parrots.
Colourful small birds include blue tits, the goldfinches, hummingbirds, fairy wrens and bee eaters (which are also called rainbow birds).
Some birds, like those of the bird of paradise in Papua New Guinea have such beautiful feathers that they have been hunted for them.
The peafowl is the best example of a display of colour to attract a mate.
Also the male domestic fowl and junglefowl have long shiny feathers above his tail and also long neck feathers that may be a different colour to his wings and body.
There are only a very few types of birds (like the eclectus parrot) where the female is more colourful than the male.
''Pied birds'' are black and white.
Black and white birds include magpies, pied geese, pelicans and Australian magpies (which are not really magpies at all).
Pied birds often have brightly coloured beaks and legs of yellow or red.
The silver pheasant, with its long white tail striped with fine bars of black, has a brightly coloured face.
Most birds can fly, and if they do, then the ability is inherited, not learnt.
They fly by pushing through the air with their wings.
The curved surfaces of the wings cause air currents (wind) which lift the bird.
Flapping keeps the air current moving to create lift and also moves the bird forward.
Some birds can glide on air currents without flapping.
Many birds use this method when they are about to land.
Some birds can also hover in the air.
This method is used by birds of prey such as falcons that are looking for something to eat.
Seagulls are also good at hovering, particularly if there is a strong breeze.
The most expert hovering birds are tiny hummingbirds which can beat their wings both backwards and forwards and can stay quite still in the air while they dip their long beaks into flowers to feed on the sweet nectar.
Types of flight
Different types of birds have different needs.
Their wings have evolved to suit their lifestyle.
Large birds of prey, such as eagles, spend a lot of time soaring on the wind.
They have wings that are large and broad.
The main flight feathers are long and wide.
They help the eagle to stay on rising air currents without using much energy, while the eagle looks at the ground below, to find the next meal.
When the eagle sees some small creature move, it can close its wings and fall from the sky like a missile, opening its great wings again to slow down as it comes to land.
The world's largest eagle, the Philippine eagle has a wingspan of about 2 m (6.7 ft) wide.
Birds that live in grassland areas or open forests and feed on fruit, insects and reptiles often spend a lot of time flying short journeys looking for food and water.
They have wings that are shaped in a similar way to eagles, but rounder and not as good for soaring.
These include many Australian birds like cockatoos.
Birds such as geese that migrate from one country to another fly very long distances.
Their wings are big and strong, because the birds are large.
They stock up on food for the long flight.
Migrating water birds usually form family groups of 1230 birds.
They fly very high, making use of long streams of air that blow from north to south in different seasons.
They are well organised, often flying in a V pattern.
The geese at the back do not have to flap so hard; they are pulled on by the wind of the ones at the front.
Every so often, they change the leader so that the front bird, who does most work and sets the pace, can have a rest.
Geese and swans are the highest-flying birds, reaching 8,000 metres or more when on migration.
Geese often honk loudly while they are flying.
It is thought that they do this to support the leader and help the young ones.
Birds that fly very quickly, such as swifts and swallows, have long narrow pointed wings.
These birds need great speed because they eat insects, catching most of them while they are flying.
These birds also migrate.
They often collect in huge flocks of thousands of birds that move together like a whirling cloud.
Birds that live in bushes and branches have triangular wings that help the bird change direction.
Many forest birds are expert at getting up speed by flapping and then gliding steadily among the trees, tilting to avoid things as they go.
Members of the kingfisher family are expert at this type of flying.
Birds such as owls that hunt at night have wings with soft rounded feathers so that they do not flap loudly.
Birds that are awake at night are called nocturnal birds.
Birds that are awake during the day are diurnal.
Wandering albatross might spend several years without coming to land.
They can sleep while gliding.
Arctic terns nest every one to three years.
Flocks of birds can be very highly organised in a way that takes care of all the flock members.
Studies of small flocking birds like tree sparrows show that they clearly communicate with each other, as sometimes thousands of birds may fly in close formation and spiral patterns without colliding (or flying into each other).
Two common behaviours in flocking birds are guarding and reconnaissance.
When a flock of birds is feeding it is common for one bird to perch on a high place to keep guard over the flock.
In the same way, when a flock is asleep, often, one bird will remain awake.
It is also common for large flocks to send one or two birds ahead of them when they are flying to a new area.
The look-out birds can spy the lie of the land to find food, water and good places to perch.
Mixed feeding flocks occur, and can help to spot predators.
Some birds do not fly.
Flightlessness in birds has evolved many times.
These include running birds like ostriches and emus and ocean-living birds, the large penguin family.
Birds on islands have usually lost the power of flight.
This is to their advantage because birds with the power of flight can be blown off their island during a storm.
The same ability which got them to the island may later take them away in a storm.
Ostriches and emus do not need to fly because although they feed and nest on the ground, their great size and their speed is their protection.
Some other ground-feeding birds have not been so lucky.
Some birds such as the dodo and the kiwi were ground-feeding birds that lived in safety on islands where there was nothing dangerous to eat them.
They lost the power of flight.
Kiwis are endangered because European settlement to New Zealand brought animals like cats, dogs and rats which kill kiwis and eat their eggs.
However, kiwis and also the rare New Zealand ground parrot have survived.
In the case of dodos, they were fat and disgusting in taste.
All the same, they were killed and eaten by sailors until there was none left.
Other flightless birds which have disappeared are the great auk and the moa.
Penguins are a very successful group of birds.
They are a clade.
They spend half their time on land.
Their wings are adapted to life in the sea and have become flippers which let them in swim fast.
They catch fish at sea, where they are in danger from seals.
Modern birds do not have teeth, and many swallow their prey whole.
Nevertheless, they must break up food before it is digested.
First of all, along their throat (oesophagus) they have a crop.
This stores food items before digestion.
That way a bird can eat several items, and then fly off to a quiet spot to digest them.
Their stomach comes next, with two very different parts.
One part is like a straight hollow rod (the proventriculus) which secretes mild hydrochloric acid and an enzyme to break down protein.
The other part of the stomach is the gizzard.
This is muscular, and grinds up the contents.
In herbivorous birds the gizzard contains some gastroliths (small stones or pieces of grit).
Bones of fish will mostly be dissolved by the stomach acid.
The partly digested and ground-up food now goes to the intestine, where digestion is completed, and most contents are absorbed.
Anything indigestible, for example remains of feathers, is regurgitated via the mouth, not the cloaca.
The system is effective, and carnivorous birds can swallow quite large prey.
A blue heron can swallow a fish as large as a carp successfully.
Raptors eat by holding the prey down with a foot, and tearing it apart with their beak.
Although birds are warm-blooded creatures like mammals, they do not give birth to live young.
They lay eggs as reptiles do, but the shell of a bird's egg is hard.
The baby bird grows inside the egg, and after a few weeks hatches (breaks out of the egg).
Birds in cold climates usually have a breeding season once a year in the spring.
Migratory birds can have two springs and two mating seasons in a year.
Ninety-five per cent of bird species are socially monogamous.
These birds pair for at least the length of the breeding season.
In some cases this arrangement lasts until the death of one of the pair.
Monogamy clearly helps if females need males' help to raise a brood successfully.
It has other practical advantages: the nest is never left without defence.
Birds are generally small, and they have many potential enemies.
Some birds mate for life, like married couples.
These birds include pigeons, geese, and cranes.
Other birds look for new partners each year.
For birds that choose new mates, part of the breeding season is display.
The male bird will do all sorts of things to attract females.
These include singing, dancing, showing off the feathers and building a beautiful nest.
Some male birds have splendid feathers for attracting females.
The most famous is the peacock who can spread the feathers above his tail into a huge fan.
Other mating systems do occur in some species.
Polygyny, polyandry, polygamy, polygynandry, and promiscuity do happen.
Polygamous breeding systems arise when females are able to raise broods without the help of males.
Some species may use more than one system depending on the circumstances.
Once the birds have found partners, they find a suitable place to lay eggs.
The idea of what is a suitable place differs between species, but most build bird nests.
The bird is driven by a hormone (estradiol E2) to prepare a place for the eggs to hatch.
Birds' nests may be up a tree, in a cliff or on the ground according to species.
When filled with eggs they are almost always guarded by one of the pair.
In fact it is virtually impossible for the eggs to survive if one of the parents dies.
Robins will make a beautiful little round nest of woven grass and carefully line it with feathers, bits of fluff and other soft things.
Swallows like to nest near other swallows.
They make nests from little blobs of clay, often on a beam near the roof of a building where it is well sheltered.
Many birds like a hollow tree to nest in.
Eagle's nests are often just piles of dead wood on the top of the tallest tree or mountain.
Scrub turkeys scratch together a huge pile of leaves that may be 10 metres across.
Guillemots lay their eggs on rock shelves with no nest at all.
Their eggs are shaped so that they roll around in circles and do not fall off cliffs.
A cuckoo does not make its own nest.
It lays its egg in the nest of another bird and leaves it for them to care for.
The cuckoo eggs are camouflaged to look like the host's eggs.
When the nest has been prepared, the birds mate so that the eggs are fertilised and the chicks will start growing.
Unlike mammals, birds (and reptiles) only have one opening as the exit hole for body fluids, and for reproduction.
The opening is called the cloaca.
A female bird, called a hen, has two ovaries, of which the left one usually produces eggs.
Most male birds have no sex organs that can be seen.
But inside the male are two testes which produce sperm which is stored in the cloaca.
Birds mate by rubbing their cloacas together, although with some birds, particularly large water birds, the male has a sort of a penis inside the cloaca.
Once the hen has mated, she produces fertile eggs which have chicks growing inside them.
She lays the eggs in the nest.
There might be just one egg or a number of them, called a clutch.
Emus might lay as many as fifteen huge dark green eggs in a clutch.
After the eggs are laid, they are incubated, or kept warm so the chicks form inside.
Most birds stay together for the whole nesting season, and one advantage is that the work is shared.
Many birds take turns sitting on the eggs, so that each adult can feed.
With emus, the male does all the sitting and all the baby-minding.
With emperor penguins it is also the male that cares for the egg.
There is only one egg, which he keeps on his feet and under his feathers, standing in a big group of males without feeding until the chick is hatched.
While the eggs are hatching, the females are at sea, feeding, so that they can care for the chicks when they return.
Some birds put the eggs inside or on top of the mound of leaves and twigs.
The mound acts like a compost heap.
The decomposition of the rotting leaves causes the temperature to rise.
This is heat released by the chemical action of bacterial and fungal respiration.
It is the same reaction as that which keeps mammals and birds at a high temperature.
The parents leave the mound.
When the chicks hatch, they are able to feed themselves.
Many small birds take 2–4 weeks to hatch eggs.
Albatrosses take 80 days.
During this time the female loses a lot of her body weight.
The quickest hatching time is for the cuckoo.
Some types of cuckoos take only 10 days.
This means that when they hatch in the nest of their ''foster parents'', the eggs that the parents have laid are not yet ready.
Newborn cuckoos are naked, blind and ugly, but they are strong.
They get under any eggs that are in the nest and throw them out before they hatch.
That means that the cuckoo has the whole care of both parents.
Baby cuckoos grow fast and often get bigger than the parents who feed them.
When baby birds hatch, in most types of birds, they are fed by both parents, and sometimes by older aunties as well.
Their mouths are open all the time and are often very brightly coloured, which acts as a releaser'', a trigger which stimulates the parent to feed them.
For birds that eat grain and fruit, the parents eat and partly digest the food for the babies.
It is then vomited carefully into the baby's mouth.
As chicks grow they change the fluffy down that covers them as babies for real feathers.
At this stage they are called fledglings.
Other family members may help care for fledgling chicks, feeding them and protecting them from attack while parents are feeding.
When the fledglings have their new feathers, they come out of the nest to learn to fly.
In some types of birds, like pigeons, the parents watch over this and as the young ones get stronger, will give them flying lessons, teaching them how to glide, how to fly in spirals and how to land like an expert.
Most birds are social animals, at least part of the time.
They communicate to each other using sounds and displays.
Almost all birds make sounds to communicate.
The types of noises that vary greatly.
Some birds can sing, and  they are called songbirds or passerines.
Examples are robins, larks, canaries, thrushes, nightingales.
Corvids are passerines, but they do not sing.
Birds that are not songbirds include: pigeons, seagulls, eagles, owls and ducks.
Parrots are not songbirds, even though they can be taught to sing human songs.
All birds make noises (''bird vocalisation''), but not all sing.
Songbirds are passerines, many of which have beautiful melodic songs.
Songs have different functions.
Danger cries are different from territorial songs and mating calls are a third type.
Fledgling may also have different calls from adults.
Recognition calls for partners are quite common.
Those where the song is mainly inherited, and the bird always sings the same song in the same situations.
The capacity is inherited, and only details are learnt from its neighbours.
Those where the song is partly inherited, but the bird tunes it in by copying others.
In this case the slight differences between the calls of different birds may be used by partners for identification.
Those where the song is entirely learnt, and the bird often copies sounds from its environment.
Only the capacity to sing is inherited.
The same species of bird will sing different songs in different regions.
A good example of this is the currawong.
This is an Australia bird which is like a black and white crow.
In the autumn, families get together in large flocks and do a lot of singing.
Currawongs from some areas sing much more complex songs than others.
Generally, currawongs from the Blue Mountains are the finest singers.
The song of the currawong can be sung as a solo, but is often performed as a choir.
One bird will take the lead and sing "Warble-warble-warble-warble!"
All the other birds will join in and sing "Wooooooo!".
When all the birds know the song, the choir will sing the "Warble" part and the soloist will sing the "Woo!".
The song changes from year to year and from place to place.
Lorenz's studies
The Austrian naturalist Konrad Lorenz studied the way in which birds communicate, or talk to each other.
He found that each type of bird had a number of sounds which they made automatically, when ever they felt a certain way.
Every sound had an action that went with it.
So, if the bird was frightened, it acted frightened and made a frightened sound.
This told the other birds around it that something frightening was happening.
If a flock of birds were flying over a field, they would be calling "Fly!
Fly!"
But a hungry bird, seeing something good to eat down below might start calling "Food!
Food!"
If other birds were also hungry, they would make the same call until more birds were calling "Food!
than "Fly!
Fly!".
At this point, the mind of the flock would be changed.
Some of the birds would start to yell "Fly downwards!
Fly downwards!"
as they sank from the sky, until the whole flock was all noisily calling the same thing.
These communication sounds are often short hard sounds like: chirps, squeaks, squawks and twitters.
Sometimes the calls are longer and more musical.
They include the "Rookety-coo" sound of a pigeon and the "Cockadoodledoo!"
of a rooster.
The bird cannot change these sounds.
They always make them in the same way.
The bird is locked into making each sound every time a particular idea comes into its head.
The connection between how they feel and how they call is innate: they are born with it.
Some calls in some species are learnt.
Then, it is the tendency to learn which is inherited.
The Jackdaw of Altenberg
Konrad Lorenz noticed that when birds sing, they often use a lot of their regular calls as part of the song.
Lorenz had a flock of jackdaws which were scattered during World War II.
One day, an old bird returned.
For many months she sat on the chimney singing her song, but in the song she kept making the call which Lorenz knew meant "Come home!
Come home!"
One day, to the great surprise of Lorenz, a male bird flew from a passing flock and joined her on the chimney.
Lorenz was sure that it was her long-lost "husband" who had found his way home at last.
Evolution and taxonomy
Palaeontologists have found some exceptional places (lagerstätten) where fossils of early birds are found.
The preservation is so good that on the best examples impressions of their feathers can be seen, and sometimes even the remains of meals they have eaten.
From these remains we know that birds evolved from small carnivorous dinosaurs (theropods) in the Jurassic period.
They radiated into a huge variety in the Lower Cretaceous.
At the same time, their direct competitors, the pterosaurs, dwindled in numbers and variety, and became extinct at the end of the Mesozoic.
Birds are classified by taxonomists as 'Aves' (Avialae).
Birds are the only living descendants of dinosaurs (strictly speaking, they are dinosaurs).
Birds and Crocodilia are the only living members of the once-dominant Archosaur reptiles.
The class Aves is was defined (1990) as all the descendants of the most recent common ancestor of modern birds and Archaeopteryx lithographica.
But Archaeopteryx is almost certainly not the ancestor of modern birds.
The transition to flight happened a number of times.
The researchers offered four definitions.
Birds can be:
All archosaurs closer to birds than crocodiles (Avemetatarsalia).
Advanced archosaurs with feathers (Avofilopluma).
Those feathered dinosaurs that fly (or Avialae)
Aves can mean the last common ancestor of all living birds and all of its descendants (a "crown group", in this sense synonymous with Neornithes).
The first bird-like creatures Archaeopteryx, from the Upper Jurassic some 150–145 million years ago (mya), was for a long time the earliest known bird which could fly.
It is famous, because it was one of the first important fossils found after Charles Darwin published his ideas about evolution in the 19th century.
By modern standards, Archaeopteryx could not fly very well.
Other early fossil birds are, for example, Confuciusornis, Anchiornis huxlei and other Paraves.
Many fossils of early birds and small dinosaurs have been discovered in the Liaoning Province of Northeast China.
These include Anchiornis huxlei, from about 160 mya.
The fossils show that most small theropod dinosaurs had feathers.
These deposits have preserved them so well that the impressions of their feathers can be clearly seen.
This leads us to think that feathers evolved first as heat insulation and only later for flight.
The origin of birds lies in these small feathered dinosaurs.
Palaeontologists now agree that birds are included in Maniraptora group of dinosaurs.
This explains why we say that birds are living dinosaurs.
Evolution of modern birds
A leading authority says "Most living birds have fossil representatives in the Cenozoic"... "Key problems remain in understanding bird phylogeny... we seem to understand as little about the relationships among living birds as among Cretaceous birds".
Birds and people
Some birds are eaten as food.
Most usually it is the chicken and its eggs, but people often also eat geese, pheasants, turkeys and ducks.
Other birds are sometimes eaten are: emus, ostriches, pigeons, grouse, quails, doves, woodcocks and even songbirds.
Some species have died out because they have been hunted for food, for example the dodo and the passenger pigeon.
Many species have learned how to get food from people.
The number of birds of these species has grown because of it.
Seagulls and crows find food from garbage dumps.
The feral pigeon (Columba livia), sparrows (Passer domesticus and starlings (Sturnus vulgaris) live in large numbers in towns and cities all over the world.
Sometimes people also use working birds.
For example, homing pigeons carry messages.
Nowadays people sometimes race them for sport.
People also use falcons for hunting, and cormorants for fishing.
In the past, people in mines often used a canary to see if there were bad gas methane in the air.
People often have colorful birds such as parrots and mynahs as pets.
These intelligent birds are popular because they can copy human talking.
Because of this, some people trap birds and take them to other countries to sell.
This is not usually allowed these days.
Most pet birds are specially bred and are sold in pet shops.
People can catch some bird diseases, for example: psittacosis, salmonellosis, campylobacteriosis, Newcastle's disease, mycobacteriosis, influenza, giardiasis and cryptosporiadiosis.
In 2005, there was an epidemic of bird influenza spreading through some parts of the world, often called avian flu.
Some people have birdboxes in their gardens to give birds a place to nest and bird tables where birds can get food and water in very cold or very dry weather.
This lets people see some small birds close up which are normally hidden away in bushes and trees.
Bird orders
Infraclass Palaeognathae
Superorder Struthionimorphae
Struthioniformes
Superorder Notopalaeognathae
Rheiformes
Tinamiformes
Casuariiformes
Apterygiformes
Infraclass Neognathae
Superorder Galloanserae
Superorder Neoaves
Phoenicopteriformes
Podicipediformes
Mesitornithiformes
Pteroclidiformes
Cuculiformes
Otidiformes
Musophagiformes
Opisthocomiformes
Gaviiformes
Sphenisciformes
Cathartiformes
Strigiformes
Coliiformes
Leptosomiformes
Trogoniformes
Psittaciformes
Passeriformes
Bird population decreasing
A report produced by BirdLife International every five years measures the population of birds worldwide.
One in every eight types of birds is now "in decline".
Avibase - The World Bird Database
Bird Hybrids Database - Search by bird name, use Sibley classification
International Ornithological Committee
Freedom of speech is the right to state one's opinions and ideas without being stopped or punished.
Sometimes this is also called Freedom of expression.
Freedom of speech is thought to also include freedom of the press and Freedom of information.
However, new laws are usually needed to allow information to be used easily.
Most people think freedom of speech is necessary for a democratic government.
In countries without free speech, people might be afraid to say what they think.
Then, the government does not know what the people want.
If the government does not know what they want, it cannot respond to their wants.
Without free speech, the government does not have to worry as much about doing what the people want.
Some people say this is why some governments do not allow free speech: they do not want to be criticised, or they fear there would be revolution if everyone knew everything that was happening in the country.
A well-known liberal thinker, John Stuart Mill, believed that freedom of speech is important because the society that people live in has a right to hear people's ideas.
It's not just important because everyone should have a right to express him or herself.
Few countries with "free speech" let everything be said.
For example, the United States Supreme Court said that it was against the law to shout "fire" in a crowded theater if there is no fire, because this might cause people to panic.
The International Covenant on Civil and Political Rights also says that it is not okay to cause national, racial or religious hatred.
Also, some countries have laws against hate speech.
As Tocqueville pointed out, people may be hesitant to speak freely not because of fear of government punishment but because of social pressures.
When an individual announces an unpopular opinion, he or she may face the disdain of their community or even be subjected to violent reactions.
While this type of suppression of speech is even more difficult to prevent than government suppression is, there are questions about whether it truly falls within the ambit of freedom of speech, which is typically regarded as a legal right to be exercised against the government, or immunity from governmental action.
A banana is the common name for a type of fruit and also the name for the herbaceous plants that grow it.
These plants belong to the genus Musa.
They are native to the tropical region of southeast Asia.
It is thought that bananas were grown for food for the first time in Papua New Guinea.
Today, they are cultivated in tropical regions around the world.
Most banana plants are grown for their fruits, which botanically are a type of berry.
Some are grown as ornamental plants, or for their fibres.
There are about 110 different species of banana.
In popular culture and commerce, "banana" usually refers to the soft and sweet kind, also known as dessert bananas.
Other kinds, or cultivars, of banana have a firmer, starchier fruit.
Those are usually called plantains.
Plantains are mostly used for cooking or fibre.
Other than being used as food, beer can be made by fermenting the juice of certain cultivars in Africa, known as beer bananas.
The ash of bananas can be used to make soap.
In Asia, bananas are often planted to provide shade to plants that like shade, for example coffee, cocoa, nutmeg or black pepper.
Because of this, banana plants can often be found in plantations of other crops.
Banana plant
The banana plant is the largest herbaceous flowering plant.
Banana plants are often mistaken for trees.
Bananas have a false stem (called pseudostem), which is made by the lower part of the leaves.
This pseudostem can grow to be two to eight meters tall.
Each pseudostem grows from a corm.
A pseudostem is able to produce a single bunch of bananas.
After fruiting, the pseudostem dies and is replaced.
When most bananas are ripe, they turn yellow or, sometimes, red.
Unripe bananas are green.
Banana leaves grow in a spiral and may grow  long and  wide.
They are easily torn by the wind, which results in a familiar, frayed look.
The banana fruits grow from a banana blossom in hanging clusters, also called a bunch or banana stem.
The fruits grow in rows called tiers or hands.
There can be as many as twenty fruits to a hand, and as many as twenty tiers in a bunch.
A bunch usually weighs between 30 and 50 kilograms (65 to 110 pounds).
Each banana (or finger) has a protective outer layer (called peel or skin).
There is a fleshy part inside that readily spilts into three segments.
It is the only known tri-segmented fruit in the world.
Both the skin and inner part can be eaten.
Western cultures generally eat the inside raw and throw away the skin.
Some Asian cultures eat both the skin and the inside cooked.
Each fruit has many strings that run between the skin and the inner part.
Bananas have a lot of vitamin B6, vitamin C, and potassium.
Growing and trading bananas
Bananas are grown in at least 107 countries.
The banana species growing in the wild have fruits with many hard, large seeds, but almost all bananas grown to be eaten have seedless fruits.
Bananas are classified either as dessert bananas or as green cooking bananas.
Almost all export bananas are of the dessert types.
Only about ten to fifteen percent of all production is for export.
Dessert bananas change their color and usually turn yellow, when they are ripe; plantains and bananas generally used for cooking stay green.
Certain bananas have other colors when ripe.
The countries that produce the most bananas include India, Brazil, China, Ecuador and the Philippines.
The top five countries that exported bananas were Ecuador, Costa Rica, the Philippines, Colombia and Guatemala.
The United States, the European Union and Japan buy the most bananas.
Bananas are among the most valuable agricultural export products; They provided about sixty percent of export earnings of Saint Lucia and about twelve percent of the Gross Domestic Product of the country, between 1994 and 1996.
Some people are allergic to bananas.
There are two basic forms of these allergies.
The first is known as oral allergy syndrome.
Within an hour of eating a banana, swelling starts inside the mouth or throat.
This allergy is related to allergies caused by pollen, like that of the birch tree.
The other is similar to latex allergies.
It causes urticaria and potentially serious upper gastrointestinal symptoms.
Other uses of bananas
The fibre gained from the banana plant has been used to make textiles for a long time.
In Japan, bananas have been grown to be used for clothing and in the house since at least the 13th century.
In the Japanese system, the leaves and shoots are cut from the plant periodically to make sure they are soft.
The harvested shoots must first be boiled in lye to prepare the fibres for the making of the yarn.
These banana shoots produce fibres of varying degrees of softness.
They can be used for yarns and textiles of different qualties, and for specific uses.
For example, the outermost fibres of the shoots are the coarsest - they are good for tablecloths.
The softest innermost fibres are desirable for kimono and kamishimo.
This traditional Japanese banana cloth making process has many steps, all performed by hand.
Another system is used in Nepal.
There the trunk of the banana plant is harvested instead.
Small pieces of this trunk are then softened.
The fibres are extracted mechanically, bleached, and dried.
They are then sent to the Kathmandu Valley, where high-end rugs are produced.
These rugs have a texture and general qualities similar to that of silk.
These banana fibre rugs are woven by traditional Nepalese hand-knotted methods.
Banana fiber is also used to make banana paper.
There are two different kinds of banana paper: paper made from the bark, and paper made from the fibre and from unused fruits.
Biel/Bienne (official name; Biel is German, Bienne is French) is an industrial town in Switzerland.
It is in the part of Switzerland named Bern and near the city also named Bern.
The town is known for many companies that make watches and machines.
The wonderful old town with its  town church and its location as the gateway to the three Jura lakes (Lakes Biel, Lake Neuchâtel and Lake Murten) with vineyards on the hillsides and extensive vegetable cultivation make the town very attractive.
Swatch, Rolex, Omega, Tissot, Movado and Mikron all come from this town.
But Biel has also become important in the field of other industries and in communication.
It is possible to travel on various routes along the lakes on passenger boats in summer.
The day trip through all three Jura lakes is especially popular.
Of course there are all types of water sports on Lake Biel.
The town of Biel was built by the Prince-Bishop of Bale between 1220 and 1230.
The old town is the smallest part of Biel with only .
Most buildings there still look as in the 18th century.
The biggest part of the old town is without any traffic.
There aren’t any big stores or industries or any big companies.
Each Saturday there is a market.
The castle, “the ring” and the theatre are very popular.
The town church is on the “Ringplatz” and was built between 1451 and 1470.There they burned the witches in the 18th century.
From the 6 medieval city gates only one and two towers survived.
Heritage sites
The entire town of Biel is part of the Inventory of Swiss Heritage Sites.
Several individual buildings in the old town have also been protected for their cultural heritage.
The Reformed City Church is one of the most important late-Gothic buildings in the Canton of Bern.
The church has a main floor, two second floors and four small chapels.
There are some wall-paintings in the church.
Most windows are among the oldest ones in Switzerland.
The church was first written about in an index in 1228.
After a horrible fire in the old town the church was destroyed.
It was rebuilt between 1367 and 1451.
The town church got on a new organ on 6th November 2011.
The church was closed for more than half a year to put the new organ in and to improve the inside of the church.
It cost about 1,74 million Swiss francs.
The old organ was sent to Poland.
About 57% of the people in Biel speak German as their mother tongue.
The remaining 43% speak French as their mother tongue.
That is why the city has two names.
www.biel-bienne.ch
Dickemauern
Swatch Internet Time is a way to measure time invented in 1998 by the Swatch manufacturing firm in Biel/Bienne, Switzerland.
Time is shown as an "@" mark with three numerals.
The day starts with @000 for midnight.
Noon is @500.
Just before midnight is @999.
The thousand parts which make up a day are called "dot beats" (.beats).
Each dot beat is one minute and 26.4 seconds long.
Midnight is the same as Central European Winter Time (UTC+1)and Internet Time is the same all over the world.
It does not change during the Summer.
People can use it to plan phone calls or Internet meetings.
Most types of Linux can show Internet Time as the desktop clock.
They range in size from a couple inches to several inches long, from a few millimeters to a couple centimeters in diameter.
They are designed to allow easy heating of samples, to be held in a flame, and often are made of expansion-resistant glasses, such as borosilicate glass (known by brand-names such as Pyrex and Kimax).
A beaker is a kind of laboratory glassware.
A beaker is a cylinder with a lip and a spout (a bend in the rim of the beaker which makes it easier to pour liquids without spilling any).
A beaker is usually about the same width as its height.
This makes beakers very stable and easy to handle.
Some beakers have marks on them to show about how much volume of liquid they hold - these can not be used for exact measurements.
In chemistry, a crucible is a kind of laboratory equipment that is usually a small cup, about the size of a shot glass, made of porcelain or non-reactive metal.
Crucibles are used to heat chemical compounds to very high temperatures using a gas burner.
One of the earliest uses of platinum was as a material in crucibles.
Metals such as nickel and zirconium are also used as a modern crucible material.
Metal Technology - a manufacturer of crucibles
Lithium (from Greek lithos 'stone') is a soft, silver-white metal with symbol Li.
It is the third chemical element in the periodic table.
This means that it has 3 protons in its nucleus and 3 electrons around it.
Its atomic number is 3.
Its mass number is 6.94.
It has two common isotopes, 6Li and 7Li.
7Li is more common.
92.5% of lithium is 7Li.
Lithium is a soft silvery metal that is very reactive.
It is used in lithium batteries and certain medicines.
Lithium is one of the alkali metals.
Lithium is a silvery solid metal (when freshly cut).
It is very soft.
Thus it can be cut easily with a knife.
It melts at a low temperature.
It is very light, similar to wood.
It is the least dense metal and the least dense element in a solid or liquid state.
It can hold more heat than any other solid element.
It conducts heat and electricity easily.
It will react with water, giving off hydrogen to form a basic solution (lithium hydroxide).
Because of this, lithium must be stored in petroleum jelly.
Sodium and potassium can be stored in oil but lithium cannot because it is so light.
It will just float on the oil and not be protected by it.
Lithium also reacts with halogens.
It can react with nitrogen gas to make lithium nitride.
It reacts with air to make a black tarnish and then a white powder of lithium hydroxide and lithium carbonate.
Lithium forms chemical compounds with only one oxidation state: +1.
Most of them are white and unreactive.
They make a bright red color when heated in a flame.
They are a little toxic.
Most of them dissolve in water.
Lithium carbonate is less soluble in water than the other alkali metal carbonates like sodium carbonate.
Lithium carbonate, used in medicine
Lithium chloride, colorless crystalline solid, red flame when heated
Lithium hydroxide, strong base, used to remove carbon dioxide in spaceships
Lithium nitrate, oxidizing agent
Lithium nitride, strong base
Lithium oxide, dissolves in water to make lithium hydroxide
Lithium peroxide, reacts with water to make oxygen
It does not occur as an element in nature.
It only is in the form of lithium compounds.
The ocean has a large amount of lithium in it.
Certain granites have large amounts of lithium.
Most living things have lithium in them.
There are some places where much lithium is in the salt.
Some silicates have lithium in them.
Lithium (Greek lithos, meaning "stone") was discovered by Johann Arfvedson in 1817.
In 1818, Christian Gmelin observed that lithium salts give a bright red color in flame.
W.T. Brande and Sir Humphrey Davy later used electrolysis on lithium oxide to isolate the element.
Lithium was first used in greases.
Then nuclear weapons became a big use of lithium.
Lithium was also used to make glass melt easier and make aluminium oxide melt easier in making aluminium.
Now lithium is used mainly in batteries.
It is made by getting lithium chloride from pools and springs.
The lithium chloride is melted and electrolyzed.
This makes liquid lithium and chlorine.
As an element
Its main use is in batteries.
Lithium is used as an anode in the lithium battery.
It has more power than batteries with zinc, like alkaline cells.
Lithium ion batteries also have lithium in them, though not as an element.
It is also used in heat transfer alloys.
Lithium is used to make organolithium compounds.
They are used for very strong bases.
It is used to make special glasses and ceramics, including the Mount Palomar telescope's 200 inch mirror.
Lithium is the lightest known metal and can be alloyed with aluminium, copper, manganese, and cadmium to make strong, lightweight metals for aircraft.
In chemical compounds
Lithium compounds are used in some drugs known as mood stabilizers.
Lithium niobate is used in radio transmitters in cell phones.
Some lithium compounds are also used in ceramics.
Lithium chloride can absorb water from other things.
Some lithium compounds are used to make soap and grease.
Lithium carbonate is used as a drug to treat manic depression disorder.
Lithium carbonate is used for the treatment of bipolar disease and other mental illness conditions.
Organolithium compounds are used to make polymers and fine chemicals.
Many lithium compounds are used as reagents to make organic compounds.
Some lithium compounds like lithium aluminium hydride, lithium triethylborohydride, n-butyllithium and tert-butyllithium are commonly used as very strong bases called superbases.
Lithium compounds are used as pyrotechnic colorants and oxidizers in red fireworks and flares.
Lithium chloride and lithium bromide are used as desiccants for gas streams.
Lithium hydroxide and lithium peroxide are used to remove carbon dioxide and purify the air in spacecrafts and submarines.
Lithium hydroxide, lithium peroxide and lithium perchlorate are used in oxygen candles that supply submarines with oxygen.
Lithium aluminum hydride can also be used as a solid fuel by itself.
Lithium hydride that contains lithium-6 is used in thermonuclear weapons.
Lithium reacts with water, making irritating smoke and heat.
It is not as dangerous as the other alkali metals.
Lithium hydroxide is very corrosive.
There  are 5 isotopes of Lithium having respectively 2, 3, 4, 5 and 6 neutrons in the nucleus.
The most common isotope in nature is 3Li7 which makes up 92.58% of the total.
The second isotope which is widely available is 3Li6 which makes up 7.42% of the total.
The other 3 isotopes exist in very small quantities.
The atomic mass of Lithium is 6.939.
Beryllium is in group 2 of the periodic table, so it is an alkaline earth metal.
It is grayish (slightly gray) in color.
It has an atomic number of 4 and is symbolized by the letters Be.
It is toxic and should not be handled without proper training.
Beryllium has one of the highest melting points of the light metals: 1560 K (1287 °C).
It is added to other metals to make stronger alloys.
Beryllium-copper alloy is used in tools because it does not make sparks.
Beryllium is best known for the chemical compounds it forms.
Beryllium combines with aluminium, silicon and oxygen to make a mineral called beryl.
Emerald and aquamarine are two varieties of beryl which are used as gemstones in jewelry.
Beryllium is used to make jet aircrafts, guided missiles, spacecraft, and satellites, including the James Webb telescope.
Beryllium can reflect neutrons, and thin foils of beryllium are sometimes used in nuclear weapons as the outer layer of the plutonium pits.
Beryllium is also used in fuel rods for CANDU reactors.
Beryllium is used to make many dental alloys.
It is a relatively rare element in the universe.
It usually occurs when larger atomic nuclei have split up.
In stars, beryllium is depleted because it is fused and builds larger elements.
Alkaline earth metals
Data compression is a set of steps for packing data into a smaller space, while allowing for the original data to be seen again.