Monday, March 22, 2010

Every 20 minutes on Earth, another animal species dies out, never to be seen again. At the current rate of extinction, more than 50 percent of all living species will be gone by the end of the century. Scientists believe that we are in the midst of the sixth great extinction to occur on this planet. The first wave of the current extinction may have started a long as 50,000 years ago, but the accelerated pace is largely due to human influences such as overpopulation, loss of habitat, global warming and species exploitation. According to author Jeff Corwin, the black market for rare animal parts—such as shark fins for soup and African elephant ivory—is the third-largest illegal trade in the world, exceeded only by weapons and drugs.

Extinction is for Ever!

As almost everyone knows, to become extinct is to be gone forever. Even before man's arrival on Earth, species became extinct quite naturally. Natural extinction happens when a species declines in numbers gradually but steadily at the end of its evolutionary period on Earth. The length of this period depends on how well a species can adapt to changes in climate and changes in other animals and plants around it. This is perfectly in line with the Charles Darwin’s Law of Survival (Survival of the Fittest). This process of extinction can take a very long time - sometimes several million years - and the extinction of one species is immediately followed by the appearance of another in a continuous cycle.

The case of the dinosaurs is the most well-known example of natural extinction. These reptiles appeared on Earth about 200 million years ago and dominated both land and sea for almost 100 million years. It is not certain why the dinosaurs became extinct, but their disappearance was a natural one and new species of animals evolved to replace them.

The rate of extinction has speeded up unnaturally over the last 400 years, rising sharply since 1900. This increase in the rate of extinction is directly related to the increase in the human population over the same period of time. The vast number of humans has caused great damage to the planet, as wild habitats have been taken over, forcing animals and plants into smaller and smaller areas, until some of them have become extinct. We have also polluted some habitats with chemicals and refuse, making them unfit for wildlife. These causes of extinction are known as indirect destruction. 

Animals may also become extinct through direct destruction. This includes the hunting and capturing of animals. Man has always hunted and killed wildlife but when early humans lived more in harmony with nature, they killed animals for essential food and clothing. When firearms were invented mass destruction of species was possible. Animals have been, and still are, killed for meat, clothing,medicines, feathers, eggs, trophies, tourist souvenirs - and sometimes just for amusement. Some species are still captured in the wild for the live pet trade, even though their numbers are dwindling.

“The extinction of at least 500 species of animals has been caused by man, most of them in this century. Today there are about 5,000 endangered animals and at least one species dies out every year. There are probably many more which become extinct without anyone knowing.”

"Dead as a dodo"

The dodo has become a symbol of extinction. It was a turkey-sized flightless pigeon which lived on the island of Mauritius. When sailors landed on the island for the first time in the sixteenth century, they killed the helpless bird for food. The dodo's eggs and young were eaten by dogs, cats, pigs, rats and monkeys which man had introduced to the island. The dodo, unused to predators, very quickly declined in numbers - and it was extinct by 1681.

Greater Horseshoe Bat

There are fourteen species of bat in Britain and all of them are endangered. The greater horseshoe bat is one of the rarest. One reason for their decline is the destruction of suitable roosting sites, such as old buildings and hollow trees. They have also suffered from the use of insecticides (poisonous chemicals sprayed on to crops to kill harmful insects) which have deprived the bats of their insect food.

Siberian Tiger

Cold, snowy Siberia, in the USSR, is home to the largest of all the tigers, the Siberian tiger. It is highly endangered and there may be fewer than 200 in the wild, probably all in special nature reserves. Hunting and loss of habitat have reduced their numbers.

Loggerhead Turtle

This threatened reptile lives in the Mediterranean Sea, as well as the Black Sea and Atlantic Ocean. In the past its main dangers were hunting for its shell and meat. Now it has to put up with tourists disturbing the sandy beaches where it lays its eggs. In Turkey, hotels have been built right on its breeding sites. Out at sea, the turtles sometimes become entangled in fishing nets and drown.

Northern Bald Ibis

The Ancient Egyptians used to depict this bird in their Hierolyphics writing, but it no longer lives in Egypt. Colonies of this ibis are now found in Algeria, Morocco and Turkey. Part of the ibis' decline is due to natural causes. It nests high above the ground and its eggs are so round that some of them roll out of the nest and break. The largest colony of the Northern Bald Ibis is in Turkey, but the use of pesticides on the marshes and grasslands where it lives is reducing the numbers.

White Tailed Fish Eagle

Before man began polluting water habitats with pesticides, this spectacular bird of prey was much more numerous than it is today. In the Middle East, its population is now very small. The bird travels long distances in search of fish, and eating a number of poisoned fish causes the bird to lay infertile or thin-shelled eggs which are easily broken.

Lion-Tailed Macaque

The habitat of this small monkey is India's tropical rainforests. Many of these forests have been cleared and replaced with tea and coffee plantations. Unlike some other animals, the lion-tailed macaque has not been able to adapt to these new habitats. Poachers have also captured baby macaques, often killing their parents in the process, for illegal export to collectors.

Mandarin Duck

The mandarin duck (the brightly coloured male is illustrated) may often be seen on ponds and lakes in Britain, but its native home is across eastern Asia, in Russia, China, Korea and Japan. It may be found on water which is near forests, but the forests are being felled and the water drained, making the duck more and more endangered.

Mountain Gorilla

The Virunga volcanoes region in eastern Zaire, Rwanda and Uganda is the only home of the highly endangered mountain gorilla. It depends on dense forests for survival and these are steadily being cut down to make way for crop growing and livestock grazing. The gorilla is protected by law, but despite this, some of its so-called sanctuaries have been cleared, and hunters kill them for food and trophies.

Jackass Penguin

The jackass penguin is the only penguin to be found in Africa, and it was once the country's most common sea-bird. It lives off the coast of Namibia and South Africa, and the waters here have been over-fished by humans, depriving the birds of their food supply. Oil pollution also threatens them, as does the taking of their eggs for food.

Blue Whale

The largest animal ever to have lived on our planet, the blue whale, lives mainly in the cold waters of the Arctic and Antarctic, where it finds enough plankton to sustain it. It migrates to tropical seas to breed. The blue whale has been a protected species since 1966, but thousands were killed up until then. During the whaling season of 1930 to 1931 alone, 30,000 blue whales were killed by Antarctic whalers. Although their numbers have increased a little, there are probably less than 6,000 alive today. It will take more than one hundred years of protection before we can be sure that it will not become extinct.

Numbat

Sometimes called the banded anteater, the Numbat was once common in the bush and forest of north-eastern and southern Australia. It is now only found in the most western part of eastern Australia. When man introduced predatory animals such as cats, dogs and foxes, these animals ate many numbats. Their numbers are still declining because their habitat is being cleared for farming and mining.

Komodo Dragon

The Komodo dragon is the largest lizard in the world and lives on a few small Indonesian islands. It is a powerful predator and can measure as much as 3 metres in length. There are about 3,000 Komodo dragons in total, but they seem to be slowly declining. They live mainly on uninhabited islands, so are in no great danger from humans. Scientists think that natural causes are to blame. There are more males than females alive, and also the natural plant life seems to be changing and the lizards are not adapting well to their new environment.

Golden Lion Tamarin

This tiny monkey is one of the most endangered of all animals in South America. The few that are left, about 150, are restricted to the only remaining coastal rainforest, southwest of Rio de Janeiro, Brazil. Forest destruction is the main reason for the tamarin's decline, but it is also in danger of being captured alive and sold as a pet - a strictly illegal practice which still goes on in secret. Some captive-bred golden lion tamarins have been put back into the wild in a protected area of forest.

Spectacled Bear

This bear gets its name from a yellowish mask which makes it appear to be wearing a pair of spectacles! It lives in the forest-covered mountains of several South American countries. As the forests are cleared for farming, the bear's numbers fall. Even though it is protected by law, the spectacled bear is still killed by poachers for its fur, meat and fat.

Californian Condor

Today there are no Californian condors in the wild - the only living ones left are kept in zoos. During the nineteenth century this large bird of prey lived in the mountains of many areas of North America. It started to decline last century when it was killed by gold diggers who collected its long black feathers. Disturbance of its habitat by tourists, pesticides and low-flying aircraft also contributed to its final disappearance in the wild.

Black-Footed Ferret

The black-footed ferret is America's rarest mammal. It is probably on the edge of extinction in the wild. This ferret hunts prairie dogs on open grassland, and as this habitat has been turned into farmland, farmers have tried to eliminate the prairie dogs by putting poison down their burrows. The black-footed ferret has also been poisoned by accident.

Hooded Seal

As with all animals that live in the oceans and seas, the biggest threat to the hooded seal is hunting. It lives in the cold waters of the northern hemisphere, stretching from Canada and Greenland in the west across to Iceland and Norway in the east. The male has a strange-looking hood, or pouch, of skin above its nose which it inflates when excited. The seal’s population has been badly affected because both adults and young have been over-hunted, killed for their skins, meat, fat and oil.

Some Interesting Facts about Endangered Species  

More than one and one-half million species exist on the earth today. However, recent estimates state that at  least 20 times that many species inhabit the planet.

In the United States, 735 species of plants and 496 species of animals are listed as threatened or endangered.

266 of these listed species have recovery plans currently under development.

There are more than 1,000 animal species endangered worldwide.

There are more than 3,500 protected areas in existence worldwide. These areas include parks, wildlife refuges and other reserves. They cover a total of nearly 2 million square miles (5 million square km), or 3% of our total land area.

Aquatic species, which are often overlooked, are facing serious trouble. One third of the United States’ fish species, two-thirds of its crayfish species, and almost three-quarters of its mussel species are in trouble.

 10 to 100 million -Estimated number of species of animals, plants, fungi, and microorganisms believed to exist.
      30 - The number of species that can disappear with the loss of just one plant species.


 2 - Percent of 250,000 known plant species that have been investigated for their possible medicinal value.

 40 - Percent of all medicines prescribed in the United States today that are derived from nature or mimic naturally occurring chemicals.

38 million - Acres lost per year in tropical rainforests. Up to one half of the world’s species live in these areas.

1 species every 100 years - Natural rate of extinction.


500 species - Number of North American species that have disappeared in the last 400 years.
    15,589 - Total number of species facing extinction worldwide in 2008.
Threatened species include one in three amphibians, half of freshwater turtles, one in eight birds, and one in four mammals.