Friday, February 19, 2010

Endangered Species


Siberian tiger

An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters. Also it could mean that due to deforestation there may be a lack of food and/or water. The International Union for Conservation of Nature (IUCN) has calculated the percentage of endangered species as 40 percent of all organisms based on the sample of species that have been evaluated through 2006. (Note: the IUCN groups all threatened species for their summary purposes.) Many nations have laws offering protection to conservation reliant species: for example, forbidding hunting, restricting land development or creating preserves. Only a few of the many species at risk of extinction actually make it to the lists and obtain legal protection. Many more species become extinct, or potentially will become extinct, without gaining public notice.

Impact on biodiversity and endangered species

In order to conserve the biodiversity of the planet, one must take into consideration the reasons why so many species are becoming endangered. “Habitat loss is the most widespread cause of species endangerment in the U.S., affecting 85% of imperiled species” (Wilcove & Master, 2008, p. 416). When an animal’s ecosystem is not maintained, they lose their home and are either forced to adapt to new surroundings or perish. Pollution is another factor that causes many species to become endangered, especially a large proportion of aquatic life. Also, over-exploitation, disease (Wilcove & Master, 2008, p. 416), and climate change (Kotiaho et al., 2005, p. 1963) have led to the endangerment of several species.

However, the most important factor leading to the endangerment of the majority of wildlife in the world is the human impact on the species and their environment. “As human use of resources, energy, and space intensified over the past few centuries, the diversity of life has been substantially diminished in most parts of the world” (Ishwaran & Erdelen, 2006, p.179). Basically, as the human impact on the environment increases, the diversity of life decreases. Humans are constantly using the resources and space of other species for themselves, negatively impacting the survival rate of many creatures.

Humans also set standards for which species they think should be saved and which species they find unimportant or undesirable. For example, the coqui frog, an invasive species in Hawaii, is so common there that its “nocturnal singing” reduces the value of homes and prevents hotels from using rooms near forests. Hawaiians have proposed eliminating the frog, and several wildlife managers want to release a pathogen to kill the frogs (Minteer & Collins, 2005, p. 333). The frog has decreased the value of homes and caused a loss of business for several hotels, so the Hawaiians decided it was acceptable to get rid of the group of coqui frog living near them.

Another example where the human impact affected the welfare of a species sex in the instance of non-native mute swans establishing themselves at Arrowhead Lake in Vermont. When the population of swans grew to eight birds, the Vermont Fish and Wildlife Department decided to take action. Two swans were eventually killed, angering animal welfare organizations and people living near the lake (Minteer & Collins, 2005, p. 333). The case of the Arrowhead Lake swans demonstrates what one considers the natural environment based on human assumptions. Simply because the swans were not normally living there does not mean it is not part of their natural habitat, and there is certainly no reason for them to be destroyed because of human dissatisfaction.

Yet another example of the human impact in the lives of endangered species is that of the Preble’s meadow jumping mouse. Research has shown that the mouse is not taxonomically different from the Bear Lodge meadow jumping mouse and the US Fish and Wildlife Service has proposed removing the Preble’s mouse from the endangered species list based on this information (Minteer & Collins, 2005, p. 333).

A final example of the human impact on existing species is the issue of toe clipping in ecological research. While ecologists are doing research on different species to advance their knowledge of methods of conservation, they must take into consideration the impact they have on the wildlife they are studying. Toe clipping “has been reported to result in a number of adverse effects on the animals, including inflammation and infection of the feet and limbs” (Minteer & Collins, 2005, p. 334). This example demonstrates how humans must take into consideration the well-being of the animal even before they perform research to help conserve the species. The human impact on species and their environments has many negative effects. It is important for humans to help maintain all species in the world and not deter their development.

Species maintaining importance

“Diversity of life and living systems are a necessary condition for human development” (Ishwaran & Erdelen, 2006, p.179). Many question the importance of maintaining biodiversity in today’s world, where conservation efforts prove costly and time consuming. The fact is that the preservation of all species is necessary for human survival. Species should be saved for “aesthetic and moral justifications; the importance of wild species as providers of products and services essential to human welfare; the value of particular species as indicators of environmental health or as keystone species crucial to the functioning of ecosystems; and the scientific breakthroughs that have come from the study of wild organisms” (Wilcove & Master, 2008, p. 418). In other words, species serve as a source of art and entertainment, provide products such as medicine for human well-being, indicate the welfare of the overall environment and ecosystem, and provided research that resulted in scientific discoveries. An example of an “aesthetic justification” in conserving endangered species is that of the introduction of the gray wolf into Yellowstone National Park. The gray wolf has brought numerous amounts of tourists to the park and added to the biodiversity in the protected region (Wilcove & Master, 2008, p. 418).

Another example, supporting the conservation of endangered species as providers of products for human well-being, is the scrub mint. It has been found that the scrub mint contains an anti-fungal agent and a natural insecticide (Wilcove & Master, 2008, p. 418). Also, the deterioration of the bald eagle and the peregrine falcon “alerted people to the potential health hazards associated with the widespread spraying of DDT and other persistent pesticides” (Wilcove & Master, 2008, p. 418).

Helping preserve endangered species

It is the goal of conservationists to create and expand upon ways to preserve endangered species and maintain biodiversity. There are several ways in which one can aid in preserving the world’s species who are nearing extinction. One such way is obtaining more information on different groups of species, especially invertebrates, fungi, and marine organisms, where sufficient data is lacking.

For example, to understand the causes of population declines and extinction an experiment was conducted on the butterfly population in Finland. In this analysis, the butterflies’ endangered list classification, distribution, density, larval specificity, dispersal ability, adult habitat breadth, flight period and body size were all recorded and examined to determine the threatened state of each species. It was found that the butterflies’ distribution has declined by fifty-one and a half percent, and they have a severely restricted habitat. One example of specific butterflies who have a declining distribution rate are the Frigga’s Fritillary and Grizzled Skipper, who have been affected by habitat loss due to extensive draining of the bogs where they live (Kotiaho et al., 2005, p. 1963-1967). This experiment proves that when we know the causes of endangerment, we can successfully create solutions for the management of biodiversity.

Another way to help preserve endangered species is to create a new professional society dedicated to ecological ethics. This could help ecologists make ethical decisions in their research and management of biodiversity. Also, creating more awareness on environmental ethics can help encourage species preservation. “Courses in ethics for students, and training programs for ecologists and biodiversity managers” all could create environmental awareness and prevent violations of ethics in research and management (Minteer & Collins, 2005, p. 336). One final way in which one can conserve endangered species is through federal agency investments and protection enacted by the federal government. “Ecologists have proposed biological corridors, biosphere reserves, ecosystem management, and ecoregional planning as approaches to integrate biodiversity conservation and socioeconomic development at increasingly larger spatial scales” (Ishwaran & Erdelen, 2006, p.179).

One example of a federal mandated conservation zone is the Northwest Hawaiian Islands Marine National Monument, the largest marine protected area in the world. The monument is essential to the preservation of underwater communities and overfished regions. Only researchers working in the area are permitted to fish, no corals may be removed, and the Department of Homeland Security will enforce restrictions on vessels passing through the waters via satellite imaging. The monument will serve as a home to an estimated seven thousand species, most of which cannot be found anywhere else in the world (Raloff, 2006, p. 92). This environmental monument demonstrates the fact that it is possible to create a safe environment for endangered species, as well as maintaining some of the world’s largest ecosystems.

Captive breeding programs

Captive breeding is the process of breeding rare or endangered species in human controlled environments with restricted settings, such as wildlife preserves, zoos and other conservation facilities. Captive breeding is meant to save species from going extinct. It is supposed to stabilize the population of the species so it is no longer at risk for disappearing.

This technique has been used with success for many species for some time, with probably the oldest known such instances of captive mating being attributed to menageries of European and Asian rulers, a case in point being the Pere David's Deer. However, captive breeding techniques are usually difficult to implement for highly mobile species like some migratory birds (eg. cranes) and fishes (eg. Hilsa). Additionally, if the captive breeding population is too small, inbreeding may occur due to a reduced gene pool; this may lead to the population lacking immunity to diseases.

Legal private farming for profit

Whereas poaching causes substantial reductions in endangered animal populations, legal private farming for profit has the opposite effect. Legal private farming has caused substantial increases in the populations of both the southern black rhinoceros and the southern white rhinoceros. Dr Richard Emslie, a scientific officer at the IUCN, said of such programs, "Effective law enforcement has become much easier now that the animals are largely privately owned... We have been able to bring local communities into the conservation programmes. There are increasingly strong economic incentives attached to looking after rhinos rather than simply poaching: from eco-tourism or selling them on for a profit. So many owners are keeping them secure. The private sector has been key to helping our work. "

Conservation experts view the effect of China's turtle farming on the wild turtle populations of China and South-Eastern Asia - many of which are endangered - as "poorly understood". While they commend the gradual replacement of wild-caught turtles with farm-raised ones gradually in the marketplace ( the percentage of farm-raised individuals in the "visible" trade growing from around 30% in 2000 to around 70% ca. 2007), they are concerned with the fact that a lot of wild animals are caught to provide farmers with the breeding stock. As the conservation expert Peter Paul van Dijk noted, turtle farmers often believe in the superiority of wild-caught animals as the breeding stock, which may create an incentive for turtle hunters to seek and catch the very last remaining wild specimens of some endangered turtle species.

In 2009, researchers in Australia managed for the first time to coax southern bluefin tuna to breed in landlocked tanks, opening up the possibility of using fish farming as a way to save the species from the problems of overfishing in the wild.

Pitcher Plant

Sarracenia oreophila

pitcher.tif (531260 bytes)

The Pitcher Plant has hollow leaves which hold water, which gives it its name. There are eighty kinds of pitcher plants. They are found in tropical wetlands, mostly in Malaysia, Madagascar, and Sri Lanka.

The leaves of the pitcher plant can be from two inches to more than two feet in length. Large pitcher plants can trap small frogs and mice, and small plants can catch insects. Rainwater fills the jugs of the plant. Around the lip of the pitcher, nectar is produced. This attracts flies who like the nectar. As they search farther into the jug, they slip down into it and drown. There it is digested by the plant.

People are growing carnivorous plants in indoor greenhouses. This helps preserve these fascinating plants. If they were left to grow in their natural habitat, they would be destroyed by people draining the marshlands where the plant lives to build buildings and roads.

Arizona Cliffrose

Purshia subintegra

The Arizona Cliffrose is found in four counties in the state of Arizona: Mojave, Graham, Yavapai and Maricopa. It is a member of the Rosaceae family, which includes the rose, blackberry, and hawthorn plants.

It is an evergreen shrub that grows about 1.5 meters tall. It has white and yellow petals, and is the leaves are gray in color. It is found in limestone lakebed deposits, and is food for muledeer. People like to use them as decorative plants for their homes.

It is on the endangered species list because of the damage done to them by off-road vehicle traffic, mining, pesticides, and road construction.

Venus Fly Trap

Dionaea Muscipula

venus.tif (535676 bytes)

The Venus Fly Trap belongs to the Doseraceae, or Sundew, family of plants. There are over 150 species. The Venus Fly Trap grows in between Florida and North and South Carolina. They grow well in acidic, boggy areas.

It is a carnivorous plant, which means it eats insects. If a fly lands on its leaves, it touches the adaxial receptors, which are small hairs on the plant. These receptors have to be touched three times before the chemical reaction occurs that makes the Venus Fly Trap close its leaves in a quick motion. The fly is then stuck in the leaf and can’t get out. The bug is then "digested" by the plant. The plant can digest things three times before it dies.

Their natural habitats are being destroyed by development in its region. If you want one, it is best to buy one from a plant nursery rather than take one from its natural habitat.

You can buy a Venus Fly Trap at big hardware chain stores, and they cost about three to five dollars. You have to transplant your plant in the spring in a peat moss mix. If you want to feed your plant, you should let it have a live bug, because the motion helps its feeding instinct.


Rafflesia arnoldii

Rafflesia arnoldii is a member of the genus Rafflesia. It is noted for producing the largest individual flower on earth, and a strong odor of decaying flesh - the latter point earning it the nickname of "corpse flower". It occurs only in the rainforests of Sumatra and Borneo in the Indonesian Archipelago. Although there are some plants with larger flowering organs like the Titan Arum and Talipot palm, those are technically clusters of many flowers.

Several species of Rafflesia grow in the jungles of southeast Asia, including the Philippines. Many of them are threatened or endangered. The flower of Rafflesia arnoldii is the largest which attains a diameter of nearly one meter (3 ft) and can weigh up to 11 kilograms (24 lb).

It lives as a parasite on the Tetrastigma vine, which grows only in primary (undisturbed) rainforests. Rafflesia lacks any observable leaves, stems or even roots, yet is still considered a vascular plant. Similar to fungi, individuals grow as thread-like strands of tissue completely embedded within and in intimate contact with surrounding host cells from which nutrients and water are obtained. Perhaps the only part of Rafflesia that is identifiable as distinctly plant-like are the flowers; although, even these are unusual since they attain massive proportions, have a reddish-brown coloration and stink of rotting flesh, which is why it was nicknamed the "corpse flower". This scent attracts insects such as flies which then pollinate the rare plant. It is not to be confused with the Titan Arum, Amorphophallus titanum, which is also commonly referred to as the "corpse flower".

Wednesday, February 17, 2010

Endangered Species

Habitat Destruction

When discussing the causes of endangerment, it is important to understand that individual species are not the only factors involved in this dilemma. Endangerment is a broad issue, one that involves the habitats and environments where species live and interact with one another. Although some measures are being taken to help specific cases of endangerment, the universal problem cannot be solved until humans protect the natural environments where endangered species dwell.

There are many reasons why a particular species may become endangered. Although these factors can be analyzed and grouped, there are many causes that appear repeatedly. Below are several factors leading to endangerment:

Our planet is continually changing, causing habitats to be altered and modified. Natural changes tend to occur at a gradual pace, usually causing only a slight impact on individual species. However, when changes occur at a fast pace, there is little or no time for individual species to react and adjust to new circumstances. This can create disastrous results, and for this reason, rapid habitat loss is the primary cause of species endangerment. The strongest forces in rapid habitat loss are human beings. Nearly every region of the earth has been affected by human activity, particularly during this past century. The loss of microbes in soils that formerly supported tropical forests, the extinction of fish and various aquatic species in polluted habitats, and changes in global climate brought about by the release of greenhouse gases are all results of human activity.

It can be difficult for an individual to recognize the effects that humans have had on specific species. It is hard to identify or predict human effects on individual species and habitats, especially during a human lifetime. But it is quite apparent that human activity has greatly contributed to species endangerment. For example, although tropical forests may look as though they are lush, they are actually highly susceptible to destruction. This is because the soils in which they grow are lacking in nutrients. It may take Centuries to re-grow a forest that was cut down by humans or destroyed by fire, and many of the world's severely threatened animals and plants live in these forests. If the current rate of forest loss continues, huge quantities of plant and animal species will disappear.

Introduction of Exotic Species

Native species are those plants and animals that are part of a specific geographic area, and have ordinarily been a part of that particular biological landscape for a lengthy period of time. They are well adapted to their local environment and are accustomed to the presence of other native species within the same general habitat. Exotic species, however, are interlopers. These species are introduced into new environments by way of human activities, either intentionally or accidentally. These interlopers are viewed by the native species as foreign elements. They may cause no obvious problems and may eventual be considered as natural as any native species in the habitat. However, exotic species may also seriously disrupt delicate ecological balances and may produce a plethora of unintended yet harmful consequences.

The worst of these unintended yet harmful consequences arise when introduced exotic species put native species in jeopardy by preying on them. This can alter the natural habitat and can cause a greater competition for food. Species have been biologically introduced to environments all over the world, and the most destructive effects have occurred on islands. Introduced insects, rats, pigs, cats, and other foreign species have actually caused the endangerment and extinction of hundreds of species during the past five centuries. Exotic species are certainly a factor leading to endangerment.


A species that faces overexploitation is one that may become severely endangered or even extinct due to the rate in which the species is being used. Unrestricted whaling during the 20th century is an example of overexploitation, and the whaling industry brought many species of whales to extremely low population sizes. When several whale species were nearly extinct, a number of nations (including the United States) agreed to abide by an international moratorium on whaling. Due to this moratorium, some whale species, such as the grey whale, have made remarkable comebacks, while others remain threatened or endangered.

Due to the trade in animal parts, many species continue to suffer high rates of exploitation. Even today, there are demands for items such as rhino horns and tiger bones in several areas of Asia. It is here that there exists a strong market for traditional medicines made from these animal parts.

More Factors

Disease, pollution, and limited distribution are more factors that threaten various plant and animal species. If a species does not have the natural genetic protection against particular pathogens, an introduced disease can have severe effects on that specie. For example, rabies and canine distemper viruses are presently destroying carnivore populations in East Africa. Domestic animals often transmit the diseases that affect wild populations, demonstrating again how human activities lie at the root of most causes of endangerment. Pollution has seriously affected multiple terrestrial and aquatic species, and limited distributions are frequently a consequence of other threats; populations confined to few small areas due to of habitat loss, for example, may be disastrously affected by random factors.

Ways You Can Help Endangered Species

Conserve Habitats

  • One of the most important ways to help threatened plants and animals survive is to protect their habitats permanently in national parks, nature reserves or wilderness areas. There they can live without too much interference from humans. It is also important to protect habitats outside reserves such as on farms and along roadsides.
  • You can visit a nearby national park or nature reserve. Some national parks have special guided tours and walks for kids. Talk to the rangers to find out whether there are any threatened species and how they are being protected. You and your friends might be able to help the rangers in their conservation work.
  • When you visit a national park, make sure you obey the wildlife code: follow fire regulations; leave your pets at home; leave flowers, birds’ eggs, logs and bush rocks where you find them; put your rubbish in a bin or, better still, take it home.
  • If you have friends who live on farms, encourage them to keep patches of bush as wildlife habitats and to leave old trees standing, especially those with hollows suitable for nesting animals.
  • Some areas have groups which look after local lands and nature reserves. They do this by removing weeds and planting local native species in their place. You could join one of these groups, or even start a new one with your parents and friends. Ask your local parks authority or council for information.
  • By removing rubbish and weeds and replanting with natives you will allow the native bush to gradually regenerate. This will also encourage native animals to return.

Make Space For Our Wildlife

  • Build a birdfeeder and establish a birdbath for the neighborhood birds.
  • Plant a tree and build a birdhouse in your backyard.
  • Start composting in your backyard garden or on your balcony. It eliminates the need for chemical fertilizers which are harmful to animals and humans, and it benefits your plants!
  • Ask your parents not to use harmful chemicals in your garden or home.

Recycle, Reduce, And Reuse

  • Encourage your family to take public transportation. Walk or ride bicycles rather than using the car.
  • Save energy by turning off lights, radios and the TV when you are not using them.
  • Turn off the tap while you brush your teeth and use water-saving devices on your toilet, taps and showerhead.
  • Ask your parents to buy products and food without packaging whenever possible. Take your own bag to the store. It will reduce the amount of garbage and waste your family produces.
  • Recycle your toys, books and games by donating them to a hospital, daycare, nursery school or children's charity.
  • Encourage your family to shop for organic fruits and vegetables.
Plant Native Plants That Are Local To The Area
  • If you can, plant native plants instead of non-native or introduced ones in your garden. You don’t want seeds from introduced plants escaping into the bush. Native grasses, flowers, shrubs and trees are more likely to attract native birds, butterflies and other insects, and maybe even some threatened species.

Control Introduced Plants And Animals

  • Non-native plants and animals are ones that come from outside your local area.

  • Some parks and reserves, beaches, bush-land and rivers are now infested with invasive plants, and native species often cannot compete with these plants.

  • Many environmental weeds come from people’s gardens.

  • Sometimes, the seeds are taken into the bush by the wind or by birds.

  • Controlling these foreign species is an important step in protecting wildlife

Join An Organization
  • There are many community groups working on conservation activities. Join an organization in your area and start helping today!

Make Your Voice Heard

  • State and territory government conservation agencies are responsible for the management of national parks and the protection of wildlife. They are sometimes supported by public foundations.
  • Tell your family, friends and work mates about threatened species and how they can help them.
  • Start a group dedicated to protecting a threatened plant or animal in your area or perhaps to help care for a national park.
  • Write articles or letters about threatened species to newspapers.
  • Ring up talk-back radio programs to air your concerns, or arrange to talk on your community radio station.

Why Save Endangered Species

Plants and animals hold medicinal, agricultural, ecological, commercial and aesthetic/recreational value. Endangered species must be protected and saved so that future generations can experience their presence and value.


Plants and animals are responsible for a variety of useful medications. In fact, about forty percent of all prescriptions written today are composed from the natural compounds of different species. These species not only save lives, but they contribute to a prospering pharmaceutical industry worth over $40 billion annually. Unfortunately, only 5% of known plant species have been screened for their medicinal values, although we continue to lose up to 100 species daily.

The Pacific yew, a slow-growing tree found in the ancient forests of the Pacific Northwest, was historically considered a "trash" tree (it was burned after clearcutting). However, a substance in its bark taxol was recently identified as one of the most promising treatments for ovarian and breast cancer.

Additionally, more than 3 million American heart disease sufferers would perish within 72 hours of a heart attack without digitalis, a drug derived from the purple foxglove.


There are an estimated 80,000 edible plants in the world. Humans depend upon only 20 species of these plants, such as wheat and corn, to provide 90% of the world's food. Wild relatives of these common crops contain essential disease-resistant material. They also provide humans with the means to develop new crops that can grow in inadequate lands such as in poor soils or drought-stricken areas to help solve the world hunger problem. In the 1970s, genetic material from a wild corn species in Mexico was used to stop a leaf fungus that had previously wiped out 15% of the U.S. corn crop.


Plant and animal species are the foundation of healthy ecosystems. Humans depend on ecosystems such as coastal estuaries, prairie grasslands, and ancient forests to purify their air, clean their water, and supply them with food. When species become endangered, it is an indicator that the health of these vital ecosystems is beginning to unravel. The U.S. Fish and Wildlife Service estimates that losing one plant species can trigger the loss of up to 30 other insect, plant and higher animal species.

The northern spotted owl, listed as threatened in 1990, is an indicator of the declining health of the ancient forests of the Pacific Northwest. These forests are the home to over 100 other old-growth dependent species, which are at risk due to decades of unsustainable forest management practices.

Pollution off the coast of Florida is killing the coral reefs along the Florida Keys, which serve as habitat for hundreds of species of fish. Commercial fish species have begun to decline, causing a threat to the multi-million dollar tourism industry, which depends on the quality of the environment.


Various wild species are commercially raised, directly contributing to local and regional economies. Commercial and recreational salmon fishing in the Pacific Northwest provides 60,000 jobs and $1 billion annually in personal income, and is the center of Pacific Northwest Native American culture. This industry and way of life, however, is in trouble as salmon decline due to habitat degradation from dams, clearcutting, and overgrazing along streams.

Freshwater mussels which are harvested, cut into beads, and used to stimulate pearl construction in oysters form the basis of a thriving industry which supports approximately 10,000 U.S. jobs and contributes over $700 million to the U.S. economy annually. Unfortunately, 43% of the freshwater mussel species in North America are currently endangered or extinct.


Plant and animal species and their ecosystems form the basis of America’s multi-billion dollar, job-intensive tourism industry. They also supply recreational, spiritual, and quality-of-life values as well.

Each year over 108 million people in the United States participate in wildlife-related recreation including observing, feeding, and photographing wildlife. Americans spend over $59 billion annually on travel, lodging, equipment, and food to engage in non-consumptive wildlife recreation. Our national heritage of biological diversity is an invaluable and irreplaceable resource. Our quality of life and that of future generations depends on our preservation of plant and animal species.

Saturday, February 13, 2010

The Extinct Animals

Tyrannosaurus rex

Tyrannosaurus (pronounced /tɨˌrænɵˈsɔrəs/ or /taɪˌrænɵˈsɔrəs/, meaning 'tyrant lizard') from the Greek words τυραννος (tyrannos, meaning "tyrant") and σαυρος (sauros, meaning "lizard") , was a genus of theropod dinosaur. The species Tyrannosaurus rex ('rex' meaning 'king' in Latin), commonly abbreviated to T. rex, is a fixture in popular culture. It lived throughout what is now western North America, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the last three million years of the Cretaceous Period, approximately 68 to 65 million years ago. It was among the last non-avian dinosaurs to exist prior to the Cretaceous–Tertiary extinction event.

Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, though unusually powerful for their size, and bore two clawed digits. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it was the largest known tyrannosaurid and one of the largest known land predators, measuring up to 13 metres (43 ft) in length,[1] up to 4 metres (13 ft) tall at the hips,[2] and up to 6.8 metric tons (7.5 short tons) in weight.[3] By far the largest carnivore in its environment, Tyrannosaurus rex may have been an apex predator, preying upon hadrosaurs and ceratopsians, although some experts have suggested it was primarily a scavenger. The debate over Tyrannosaurus as apex predator or scavenger is among the longest running debates in paleontology.

More than 30 specimens of Tyrannosaurus rex have been identified, some of which are nearly complete skeletons. Soft tissue and proteins have been reported in at least one of these specimens. The abundance of fossil material has allowed significant research into many aspects of its biology, including life history and biomechanics. The feeding habits, physiology and potential speed of Tyrannosaurus rex are a few subjects of debate. Its taxonomy is also controversial, with some scientists considering Tarbosaurus bataar from Asia to represent a second species of Tyrannosaurus and others maintaining Tarbosaurus as a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with Tyrannosaurus.

Dodo : Raphus cucullatus

Mauritius, an island in the Indian Ocean, was the only home of the dodo, a large, flightless bird that weighed up to 14 kg and was very good to eat. Dodos were an easy-to-catch source of food for sailors and settlers.

Having developed in isolation, the dodo easily fell victim to this new pressure. In addition, forest clearing destroyed the bird’s habitat, and introduced pigs, goats, cats, rats, and monkeys became competitors as well as predators.

First seen by Europeans in 1507, the dodo was extinct by 1681. Today it is represented in museums by only parts of skeletons and one complete skeleton made up of many individuals.


The quagga (Equus quagga quagga) is an extinct subspecies of the Plains zebra,which was once found in great numbers in South Africa's Cape Province and the southern part of the Orange Free State. It was distinguished from other zebras by having the usual vivid marks on the front part of the body only. In the mid-section, the stripes faded and the dark, inter-stripe spaces became wider, and the rear parts were a plain brown. The name comes from a Khoikhoi word for zebra and is onomatopoeic, being said to resemble the quagga's call. The only quagga to have ever been photographed alive was a mare at the Zoological Society of London's Zoo in Regent's Park in 1870.

The quagga lived in the drier parts of South Africa, on grassland. The northern limit seems to have been the Orange River in the west and the Vaal River in the east; the south-eastern border may have been the Great Kei River. It was hunted for its meat and hide, and is one of the many victims of modern mass extinction.

The quagga was originally classified as an individual species, Equus quagga, in 1778. Over the next 50 years or so, many other zebras were described by naturalists and explorers. Because of the great variation in coat patterns (no two zebras are alike), taxonomists were left with a great number of described "species", and no easy way to tell which of these were true species, which were subspecies, and which were simply natural variants.

Long before this confusion was sorted out, the quagga had been hunted to extinction for meat, hides, and to preserve feed for domesticated stock. The last wild quagga was probably shot in the late 1870s, and the last specimen in captivity, a mare, died on August 12, 1883 at the Artis Magistra zoo in Amsterdam. Because of the confusion between different zebra species, particularly among the general public, the quagga had become extinct before it was realized that it appeared to be a separate species.

The quagga was the first extinct creature to have its DNA studied. Recent genetic research at the Smithsonian Institution has demonstrated that the quagga was in fact not a separate species at all, but diverged from the extremely variable plains zebra, Equus burchelli, between 120,000 and 290,000 years ago, and suggests that it should be named Equus burchelli quagga. However, according to the rules of biological nomenclature, where there are two or more alternative names for a single species, the name first used takes priority. As the quagga was described about thirty years earlier than the plains zebra, it appears that the correct terms are E. quagga quagga for the quagga and E. quagga burchelli for the plains zebra, unless "Equus burchelli" is officially declared to be a nomen conservandum.

After the very close relationship between the quagga and surviving zebras was discovered, the Quagga Project was started by Reinhold Rau in South Africa to recreate the quagga by selective breeding from plains zebra stock, with the eventual aim of reintroducing them to the wild. This type of breeding is also called breeding back. In early 2006, it was reported that the third and fourth generations of the project have produced animals which look very much like the depictions and preserved specimens of the quagga, though whether looks alone are enough to declare that this project has produced a true "re-creation" of the original quagga is controversial.

DNA from mounted specimens was successfully extracted in 1984, but the technology to use recovered DNA for breeding does not yet exist. In addition to skins such as the one held by the Natural History Museum in London, there are 23 known stuffed and mounted quagga throughout the world. A twenty-fourth specimen was destroyed in Königsberg, Germany (now Kaliningrad), during World War II.

Saber Tooth Tiger

Saber tooth tigers lived many, many years ago back when the earth was trapped in an Ice Age. At that time, woolly mammoths and mastodons roamed the icy land. Smilodons, which were a type of saber tooth tiger, were a tiny bit smaller than the panthers that live today. However, smilodons were heavier than panthers, weighing a whopping 440 lbs. The smilodons were the biggest kind of saber tooth. Saber tooths were very fierce predators. The saber tooth tiger was about the size of the African lion. Some saber tooth tigers grew up to 15 feet in length!

Scientists say that saber tooth tigers probably ate mammoths, antelope, deer, and buffalo. When they ate animals bigger than themselves, such as mammoths and buffalo, they would have had a big group of saber tooths, called a pack, kill the animal. Scientists also think that some saber tooth tigers could have possibly lived in grassy or woody habitats, but others could have lived in icy lands. Saber tooths lived in many places in Asia and Europe. However, some saber tooth tiger remains have been found in the La Brea tar pits in California. These bones are said to be over 10,000 years old. Obviously, the saber tooth made its way to North America.

Wooly Mammoth

The woolly mammoth is common in the fossil record. Unlike most other prehistoric animals, their remains are often not literally fossilized - that is, turned into stone - but rather are preserved in their organic state. This is due in part to the frozen climate of their habitats, and also to their massive size. Woolly mammoths are therefore among the best-understood prehistoric vertebrates known to science in terms of anatomy.

Woolly mammoths lived in two groups (maybe subspecies). One group stayed in the middle of the high Arctic, while the other group had a much wider range.

While large, woolly mammoths were not as gigantic as sometimes imagined. In fact, they were not noticeably taller than present-day Asian elephants, though they were heavier. Fully grown mammoth bulls reached heights between 2.8 m (9.2 ft) and 4.0 m (13 ft); the dwarf varieties reached between 1.8 m (5.9 ft) and 2.3 m (7.5 ft). They could weigh up to 8 tonnes (8.8 tons).[citation needed]

Woolly mammoths had a number of adaptations to the cold, most famously the thick layer of shaggy hair, up to 1 meter in length with a fine underwool, for which the woolly mammoth is named. The coats were similar to those of muskoxen and it is likely mammoths moulted in summer. They also had far smaller ears than modern elephants; the largest mammoth ear found so far was only 30 cm (12 in) long, compared to 180 cm (71 in) for an African elephant. Other characteristic features included a high, peaked head that appears knob-like in many cave paintings and a high shoulder hump resulting from long spines on the neck vertebrae that probably carried fat deposits. Another feature at times found in cave paintings was confirmed by the discovery of the nearly intact remains of a baby mammoth named Dima. Unlike the trunk lobes of living elephants, Dima's upper lip at the tip of the trunk had a broad lobe feature, while the lower lip had a broad, squarish flap.

Their teeth were also adapted to their diet of coarse tundra grasses, with more plates and a higher crown than their southern relatives. Their skin was no thicker than that of present-day elephants, but unlike elephants they had numerous sebaceous glands in their skin which secreted greasy fat into their hair, improving its insulating qualities. They had a layer of fat up to 8 cm (3.1 in) thick under the skin which, like the blubber of whales, helped to keep them warm.

Woolly mammoths had extremely long tusks — up to 5 m (16 ft) long — which were markedly curved, to a much greater extent than those of elephants. It is not clear whether the tusks were a specific adaptation to their environment, but it has been suggested[who?] that mammoths may have used their tusks as shovels to clear snow from the ground and reach the vegetation buried below. This is evidenced by flat sections on the ventral surface of some tusks. It has also been observed in many specimens that there may be an amount of wear on top of the tusk that would suggest some animals had a preference as to which tusk it rested its trunk on.

Tasmanian Tiger

The thylacine (pronounced /ˈθaɪləsaɪn/, or in Australia /ˈθaɪləsiːn/, also /ˈθaɪləsɨn/) (binomial name: Thylacinus cynocephalus; Greek for "dog-headed pouched one") was the largest known carnivorous marsupial of modern times. It is commonly known as the Tasmanian tiger (because of its striped back), the Tasmanian wolf, and colloquially the Tassie (or Tazzy) tiger or simply the tiger. Native to continental Australia, Tasmania and New Guinea, it is thought to have become extinct in the 20th century. It was the last extant member of its genus, Thylacinus, although several related species have been found in the fossil record dating back to the early Miocene.

The thylacine had become extremely rare or extinct on the Australian mainland before European settlement of the continent, but it survived on the island state of Tasmania along with several other endemic species, including the Tasmanian devil. Intensive hunting encouraged by bounties is generally blamed for its extinction, but other contributory factors may have been disease, the introduction of dogs, and human encroachment into its habitat. Despite its official classification as extinct, sightings are still reported, though none proven.

Like the tigers and wolves of the Northern Hemisphere, from which it obtained two of its common names, the thylacine was an apex predator. As a marsupial, it was not closely related to these placental mammals, but because of convergent evolution it displayed the same general form and adaptations. Its closest living relative is thought to be either the Tasmanian devil or numbat.

The thylacine was one of only two marsupials to have a pouch in both sexes (the other being the water opossum). The male thylacine had a pouch that acted as a protective sheath, protecting the male's external reproductive organs while running through thick brush.
The modern Thylacine first appeared about 4 million years ago. Species of the Thylacinidae family date back to the beginning of the Miocene; since the early 1990s, at least seven fossil species have been uncovered at Riversleigh, part of Lawn Hill National Park in northwest Queensland. Dickson's Thylacine (Nimbacinus dicksoni) is the oldest of the seven discovered fossil species, dating back to 23 million years ago. This thylacinid was much smaller than its more recent relatives. The largest species, the powerful thylacine (Thylacinus potens) which grew to the size of a wolf, was the only species to survive into the late Miocene. In late Pleistocene and early Holocene times, the modern Thylacine was widespread (although never numerous) throughout Australia and New Guinea.
The skulls of the Thylacine (left) and the Timber Wolf, Canis lupus, are almost identical although the species are unrelated. Studies show the skull shape of the Red Fox, Vulpes vulpes, is even closer to that of the Thylacine.

An example of convergent evolution, the thylacine showed many similarities to the members of the Canidae (dog) family of the Northern Hemisphere: sharp teeth, powerful jaws, raised heels and the same general body form. Since the thylacine filled the same ecological niche in Australia as the dog family did elsewhere it developed many of the same features. Despite this, it is unrelated to any of the Northern Hemisphere predators.

The indigenous peoples of Australia made first contact with the thylacine. Numerous examples of thylacine engravings and rock art have been found dating back to at least 1000 BC. Petroglyph images of the Thylacine can be found at the Dampier Rock Art Precinct on the Burrup Peninsula in Western Australia. By the time the first explorers arrived, the animal was already rare in Tasmania. Europeans may have encountered it as far back as 1642 when Abel Tasman first arrived in Tasmania. His shore party reported seeing the footprints of "wild beasts having claws like a Tyger". Marc-Joseph Marion du Fresne, arriving with the Mascarin in 1772, reported seeing a "tiger cat". Positive identification of the Thylacine as the animal encountered cannot be made from this report since the Tiger Quoll (Dasyurus maculatus) is similarly described. The first definitive encounter was by French explorers on 13 May 1792, as noted by the naturalist Jacques Labillardière, in his journal from the expedition led by D'Entrecasteaux. However, it was not until 1805 that William Paterson, the Lieutenant Governor of Tasmania, sent a detailed description for publication in the Sydney Gazette.

The first detailed scientific description was made by Tasmania's Deputy Surveyor-General, George Harris in 1808, five years after first settlement of the island. Harris originally placed the Thylacine in the genus Didelphis, which had been created by Linnaeus for the American opossums, describing it as Didelphis cynocephala, the "dog-headed opossum". Recognition that the Australian marsupials were fundamentally different from the known mammal genera led to the establishment of the modern classification scheme, and in 1796 Geoffroy Saint-Hilaire created the genus Dasyurus where he placed the thylacine in 1810. To resolve the mixture of Greek and Latin nomenclature the species name was altered to cynocephalus. In 1824, it was separated out into its own genus, Thylacinus, by Temminck. The common name derives directly from the genus name, originally from the Greek θύλακος (thýlakos), meaning "pouch" or "sack".

Several studies support the thylacine as being a basal member of the Dasyuromorphia and that the Tasmanian devil is its closest living relative. However, research published in Genome Research in January 2009 suggests that the numbat may be more basal than the devil and more closely related to the thylacine

Steller's Sea Cow

Steller's sea cow (Hydrodamalis gigas) is a large extinct sirenian mammal. Formerly abundant throughout the North Pacific, its range was limited to a single, isolated population on the uninhabited Commander Islands by 1741 when it was first described by Georg Wilhelm Steller, chief naturalist on an expedition led by explorer Vitus Bering. Within 27 years of discovery by Europeans, the slow moving and easily
captured Steller's sea cow was hunted to extinction.

The sea cow grew at least 8 metres (26 ft) long, much larger than the manatee or dugong. Steller's work contains two contradictory weights: 4 and 24.3 tons. The true value probably lies between these figures, around 8-10 tons. It looked somewhat like a large seal, but had two stout forelimbs and a whale-like tail. According to Steller, "The animal never comes out on shore, but always lives in the water. Its skin is black and thick, like the bark of an old oak…, its head in proportion to the body is small…, it has no teeth, but only two flat white bones—one above, the other below". It was completely tame, according to Steller. They fed on a variety of kelp. Wherever sea cows had been feeding, heaps of stalks and roots of kelp were washed ashore. The sea cow was also a slow swimmer and apparently was unable to submerge.

The population of sea cows was small and limited in range when Steller first described them. Steller said they were numerous and found in herds, but zoologist Leonhard Hess Stejneger later estimated that at discovery there had been less than 1,500 remaining, and thus had been in immediate danger of extinction from overhunting by humans. They were quickly wiped out by the sailors, seal hunters, and fur traders that followed Bering's route past the islands to Alaska, who hunted them both for food and for their skins, which were used to make boats. They were also hunted for their valuable subcutaneous fat, which was not only used for food (usually as a butter substitute), but also for oil lamps because it did not give off any smoke or odor and could be kept for a long time in warm weather without spoiling. By 1768, 27 years after it had been discovered by Europeans, Steller's sea cow was extinct.

Fossils indicate that Steller's sea cow was formerly widespread along the North Pacific coast, reaching south to Japan and California. Given the rapidity with which its last population was eliminated, it is likely that aboriginal hunting caused its extinction over the rest of its original range (aboriginal peoples apparently never inhabited the Commander Islands).

It has been argued that the sea cow's decline may have also been an indirect response to the harvest of sea otters by aboriginal people from the inland areas. With the otters reduced, the population of sea urchins would have increased and reduced availability of algae, the Steller's Sea Cow's primary source of food. Thus, aboriginal hunting of both species may have contributed to the sea cow's disappearance from continental shorelines.However, in historic times aboriginal hunting had depleted sea otter populations only in localized areas. The sea cow would have been easy prey for aboriginal hunters, who would likely have exterminated accessible populations with or without simultaneous otter hunting. In any event, the sea cow was limited to coastal areas off islands without a human population by the time Bering arrived, and was already endangered.

Irish Deer

The Irish Elk or Giant Deer (Megaloceros giganteus), was a species of Megaloceros and one of the largest deer that ever lived. Its range extended across Eurasia, from Ireland to east of Lake Baikal, during the Late Pleistocene. The latest known remains of the species have been carbon dated to about 7,700 years ago. Although large numbers of skeletons have been found in Irish bogs, its common name, Irish Elk, is misleading as the animal was not exclusively Irish, and neither was it closely related to either of the living species currently called elk; for this reason, the name "Giant Deer" is preferred in more recent publications.

Megaloceros giganteus first appeared about 400,000 years ago. It possibly evolved from M. antecedens. The earlier taxon — sometimes considered a paleosubspecies M. giganteus antecedens — is similar but had more compact antlers.

The Irish Elk stood about 2.1 metres (6.9 ft) tall at the shoulders, and it had the largest antlers of any known cervid (a maximum of 3.65 m (12.0 ft) from tip to tip and weighing up to 40 kilograms (88 lb)). In body size, the Irish Elk matched the extant moose subspecies of Alaska (Alces alces gigas) as the largest known deer. A significant collection of M. giganteus skeletons can be found at the Natural History Museum in Dublin.

The size of Irish Elk antlers is distinctive, and several theories have arisen as to their evolution. One theory was that their antlers, under constant and strong sexual selection, increased in size because males were using them in combat for access to females; it was also suggested that they eventually became so unwieldy that the Irish Elk could not carry on the normal business of life and so became extinct. It was not until Stephen Jay Gould's important 1974 essay on Megaloceros that this theory was tested rigorously.

Gould demonstrated that for deer in general, species with a larger body size have antlers that are more than proportionately larger, a consequence of allometry, or differential growth rate of body size and antler size during development. Irish Elk had antlers of just the size one would predict from their body size. This does not mean that sexual selection played no part in maintaining large antler size, only that the antlers of the species' ancestors were already large to begin with. Indeed, Gould concluded that the large antler size and their position on the skull was very much maintained by sexual selection: they were morphologically ill-suited for combat between males, but their position was ideal to present them to intimidate rivals or impress females. Unlike other deer, M. giganteus did not even have to turn its head to present the antlers to best effect, but could accomplish this by simply looking straight ahead.

Discussion of the cause of their extinction has focused on the antlers (rather than on their overall body size), which may be due more to their impact on the observer than any actual property. Some have suggested hunting by man was a contributing factor in the demise of the Irish Elk as it may have been with other prehistoric megafauna, even assuming that the large antler size restricted the movement of males through forested regions or that it was by some other means a "maladaptation" (see Gould 1974). But evidence for overhunting is equivocal, and as a continental species, it would have co-evolved with humans throughout its existence and presumably have adapted to their presence.

A folk memory of the Irish Elk was once thought to be preserved in the Middle High German word Shelch, a large beast mentioned in the 13th-century Niebelungenlied along with the then-extant aurochs (Dar nach schluch er schiere, einen Wisent und einen Elch, Starcher Ure vier, und einen grimmen Schelch / "After this he straightway slew a Bison and an Elk, Of the strong Wild Oxen four, and a single fierce Schelch."). The Middle Irish word segh was also suggested as a reference to the Irish Elk. These interpretations are now considered improbable.

More recent research pointed out that high amounts of calcium and phosphate compounds are required to form antlers, and therefore large quantities of these minerals are required for the massive structures of the Irish Elk. The males (and male deer in general) met this requirement partly from their bones, replenishing them from food plants after the antlers were grown or reclaiming the nutrients from discarded antlers (as has been observed in extant deer). Thus, in the antler growth phase, Giant Deer were suffering from a condition similar to osteoporosis.

When the climate changed at the end of the last glacial period, the vegetation in the animal's habitat also changed towards species that presumably could not deliver sufficient amounts of the required minerals, at least in the western part of its range. The most recent specimen of M. giganteus in northern Siberia, dated to approximately 8,000 years ago - well after the end of the last glacial period - shows no sign of nutrient stress. They come from a region with a continental climate where the proposed vegetation changes had not (yet) occurred.

It is easy to advance a number of hypotheses regarding the disappearance of the more localized populations of this species. The situation is less clear regarding the final demise of the Irish Elk in continental Eurasia east of the Urals. Stuart et al. (2004) tentatively suggest that a combination of human presence along rivers and slow decrease in habitat quality in upland areas presented the last Irish Elk with the choice of either good habitat but considerable hunting pressure, or general absence of humans in a suboptimal habitat.

Caspian Tiger

The Caspian tiger (Panthera tigris virgata), also known as the Persian tiger, Turanian tiger, Mazandaran tiger or Hyrcanian tiger was found in Iran, Caucasus, Iraq, Afghanistan, Turkey, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan until it apparently became extinct in the late 1950s, though there have been several alleged sightings of the tiger in the more recent years.First thought to have been it's own distinct subspecies, genetic research in 2009 proved that the animal was closely related to the Siberian tiger (P. t. altaica). Separated by only one letter of genetic code, it is believed that the two split off from each other only in the past century. Some researchers suggest that it may be possible to reintroduce the closely related Siberian Tiger to the Caspian tiger's historical range in hopes of recreating this now-extinct big cat.

The Caspian tiger's body was generally less massive than that of its Far Eastern cousins, and its average size slightly less. In Turkestan, male tigers exceeded 200 cm in length, though an estimated body length of 270 cm was recorded. Females were smaller in size, normally ranging between 160-180 cm. The maximum known weight was 240 kg. Maximum skull length in males was 297.0-365.8 mm, while that of females was 195.7-255.5 mm. Although tigers from Turkestan never reached the size of the Siberian tiger, there are records of very large individuals of the former population. On January 10, 1954, a tiger killed on the Sumbar in Kopet-Dag had a skull length of 385 mm, which is considerably more than the known maximum for this population and slightly exceeds that of most Far Eastern tigers, though tigers in Manchuria have been recorded as having larger skulls of 406 mm in length.

The main background colour of its pelage varied, though generally, it was brighter and more uniform than that of Far Eastern tigers. The stripes were narrower, fuller and more closely set than those of the Siberian tiger. The colour of its stripes were a mixture of brown or cinnamon shades. Pure black patterns were invariably found only on the head, neck, the middle of the back and at the tip of the tail. Angular patterns at the base of the tail were less developed than those of the Far Eastern populations. The contrast between the summer and winter coats was sharp, though not to the same extent as in Far Eastern populations. The winter coat was paler, with less distinct patterns. The summer coat had a similar density and hair length to that of the Bengal tiger, though its stripes were usually narrower, longer and closer set.

In the southeast Trans-Caucasus, the Caspian tiger was mostly confined to the forests of the Talysh lowlands in areas where streams and reed thickets along marine lagoons were adjacent. In Turkmenistan, Uzbekistan and Tajikistan, the tiger favored river and lake basins, densely grown reeds, plume grass or tugai forests consisting of poplar, oleaster and willow. The Caspian tiger was sometimes encountered in montane belts, in summer ascending up to the permanent snowling in Kazakhstan and Kyrgyzstan. Tigers were captured in fir and juniper groves at heights of 2,500-3,000 meters above sea level in Kygryz, Trans-Ili and Dzhunarsk Alatau mountains. Generally, the Caspian tiger thrived in areas with an abundance of wild boar and Bactrian deer, large water supplies, dense thickets and low snow cover.

In the southeast Trans-Caucasus, the Caspian tiger's main prey was wild boar, though it occasionally fed on roe deer, red deer and domestic animals such as dogs and cattle in winter. Tigers in Iran ate the same species with the addition of gazelle. The Caspian tiger's prey in Turkmenistan, Uzbekistan and Kazakhstan was primarily boar, as well as Bactrian deer. In the lower Amu-Darya River, tigers sometimes preyed on jackals, jungle cats and locusts. On the Zhana-Darya and around the Aral Sea in Kazakhstan, as well as boar, the tiger fed on saiga, goitered gazelle, wild horses, Mongolian Wild Ass and mountain sheep. In Tadzhikistan and other regions of central Asia, as well as Kazakhstan, tigers frequently attacked dogs, horses and rarely camels. In Baikal, the Caspian tiger fed on wild boar, roe deer, Manchurian wapiti, moose and livestock. Like the Siberian tiger, the Caspian tiger rarely became a man-eater, unlike the Bengal tiger.

New genetic analysis revealed that the extinct Caspian tiger lives on in the Siberian Tiger (Panthera tigris altaica). Researchers from the University of Oxford in the United Kingdom collected tissue samples from 20 Caspian tiger specimens kept in museums across Eurasia. Afterwards, researchers from the U.S. National Cancer Institute (NCI) Laboratory of Genomic Diversity in Frederick, Maryland, sequenced parts of five mitochondrial genes. The Caspian Tiger's mitochondrial DNA is only one letter of genetic code separated from Siberian Tiger DNA, while it is readily distinguishable from the DNA of other tiger subspecies. This indicates that the Caspian and the Siberian subspecies are really one. The scientists have concluded that the two are so similar because both were descended from the same migrating ancestor. The ancestor colonized Central Asia via the narrow Gansu Corridor (Silk Road) from eastern China. The researchers suggest that through the early 1900s, Caspian and Siberian tiger populations intermingled, but hunters subsequently isolated the two groups. This resulted in the Siberian population splitting off from the Caspian population only in the past century.

Until the 19th century, Caspian tigers still inhabited wide spaces of Western and Central Asia. In the mid-1800s, Caspian tigers were killed 180 km northeast of Atbasar, Kazakhstan and as far North as near Barnaul, Russia (Ognev 1935, Mazák 1981). The only reported Caspian tiger from Iraq was killed near Mosul in 1887 (Kock 1990). In 1899, the last Caspian tiger near the Lop Nur basin in Xinjiang, China, was killed (Ognev 1935). Caspian tigers disappeared from the Tarim River basin in Xinjiang, China, by the 1920s. (Nowell & Jackson 1996) In 1922, the last known tiger in the Caucasus region was killed near Tbilisi, Georgia, after killing domestic livestock (Ognev 1935). The last record of the Caspian tiger on the Ili River, their last stronghold in the region of Lake Balkhash, Kazakhstan, dates to 1948. (Nowell & Jackson 1996)

The Russian government had worked heavily to eradicate the Caspian tiger during planning a huge land reclamation program in the beginning of the 20th century. They considered there was no room for the tiger in their plans and so instructed the Russian army to exterminate all tigers found around the area of the Caspian Sea, a project that was carried out very efficiently. Once the extermination of the Caspian tiger was almost complete, the farmers cleared forests and planted crops like rice and cotton. Due to intensive hunting and deforestation, the Caspian tiger retreated first from the lush lowlands to the forested ranges, then to the marshes around some of the larger rivers, and finally, deeper into the mountains, until it almost certainly became extinct. In 1938, national park Tigrovaya Balka was opened in Tajik SSR to save Riparian forests and rare animals, including Caspian Tiger, but it didn't help the population of tigers. It was the last stronghold of the Caspian tiger in the Soviet Union. Tigrovaya Balka national park is situated in Tajikistan in the undercurrent of Vakhsh River between the Piandj and Kafirnighan near the border of Afghanistan. The last Caspian Tiger was seen there in 1958.

Some reports state that the last Caspian tiger was shot in Golestan National Park (Iran) or in Northern Iran in 1959 (Vuosalo 1976). However, other reports claim that the last Chinese Caspian tigers disappeared from the Manas River basin in the Tian Shan mountains, west of Ürümqi, China, in the 1960s. (Nowell & Jackson 1996) The last record from the lower reaches of the Amu Darya river near Lake Aral was an unconfirmed observation near Nukus in 1968 while tigers disappeared from the river’s lower reaches and the Pyzandh Valley once a stronghold, in the Turkmen-Uzbek-Afghan border region by the early 1970s (Heptner and Sludskii 1972). (Nowell & Jackson 1996) There are even claims of a documented killing of this subspecies at Uludere, Hakkari in Turkey during 1970 (Üstay 1990; Can 2004). Some reports even state that the final Caspian tiger was captured and killed in Northeast Afghanistan in 1997.

The most frequently quoted date is the late 1950s, but has almost no evidence to back it up. It appears this date came to be accepted after being quoted by H. Ziaie in "A Field Guide to the Mammals of Iran". Now, the most evidence reflects an even earlier date of extinction. The area of Iran that contained the last Caspian tigers was in fact the eastern region of Mazandaran, Northern Iran. According to E. Firouz in “A Guide to the Fauna of Iran, 1999”, the last tiger was killed in 1947 near Agh-Ghomish Village, 10 km East of Kalaleh, on the way to Minoodasht-Bojnoord. An exact date of extinction is unknown.

According to unanimous scientific opinion, the Caspian tiger, as a distinct population has been extinguished irreversibly. According to the confirmed official data and supported by the scientific researches (Hepter and Slutskiy, 1972)during 1900-1968 there were 9 tigers killed in Kopet Dag Mountains. According to scientists (Dement'yev and Rustamov) the last tiger was killed on 10 January 1954 at surrundings of Kone-Kosir in the valley of Sumbar River in Kopet Dag Mountains.


The aurochs or urus (Bos primigenius), the ancestor of domestic cattle, was a type of huge wild cattle which inhabited Europe, Asia and North Africa, but is now extinct; it survived in Europe until 1627.The aurochs was far larger than most modern domestic cattle with a shoulder height of 2 metres (6.6 ft) and weighing 1,000 kilograms (2,200 lb). Domestication occurred in several parts of the world at roughly the same time, about 8,000 years ago. It was regarded as a challenging quarry animal, contributing to its extinction.The last recorded live aurochs, a female, died in 1627 in the Jaktorów Forest, Poland and its skull is now the property of Livrustkammaren in Stockholm.Aurochs appear in prehistoric cave paintings, Julius Caesar's The Gallic War and as the national symbol of many European countries, states and cities such as Alba-Iulia, Kaunas, Romania, Moldavia, Mecklenburg-Vorpommern, and Uri.In 1920, German biologists the Heck brothers attempted to recreate aurochs. The resulting cattle are known as Heck cattle or Reconstructed Aurochs, and number in the thousands in Europe today with varying resemblance to original aurochs but without such impressive size.

The words "aurochs", "urus", and "wisent" have all been used synonymously in English.However, the extinct aurochs/urus is a completely separate species from the still-extant wisent (the European bison).The animal's original scientific name, Bos primigenius, was meant as a Latin translation of the German term Auerochse or Urochs, which was (possibly incorrectly) interpreted as literally meaning "primeval ox" or "proto-ox". This scientific name is now considered invalid by Integrated Taxonomic Information System (ITIS), who classify aurochs under Bos taurus – the same species as domestic cattle. In 2003, however, the International Commission on Zoological Nomenclature "conserved the usage of 17 specific names based on wild species, which are pre-dated by or contemporary with those based on domestic forms", confirming Bos primigenius for the Aurochs. Taxonomists who consider domesticated cattle a subspecies of the wild Aurochs should use B. primigenius taurus; the name B. taurus remains available for domestic cattle where it is considered to be a separate species.

The word "aurochs" (pronounced /ˈaʊrɒks/ or /ˈɔrɒks/) comes to English from German, where its normal spelling and declension today is Auerochs/Auerochse (singular), Auerochsen (genitive), Auerochsen (plural). The declension in English varies, being either "aurochs" (singular), "aurochs" (plural) or "aurochs" (singular), "aurochses" (plural). The declension "auroch" (singular), "aurochs" (plural), acknowledged by MWU, is a back-formation analogous to "pea"-from-"pease" derived from a misinterpretation of the singular form ending in the /s/ sound (being cognate to "ox/Ochs(e)"). The use in English of the plural form "aurochsen" is not acknowledged by AHD4 or MWU, but is mentioned in The Cambridge Encyclopedia of the English Language. It is directly parallel to the German plural and analogous (and cognate) to English "ox" (singular), "oxen" (plural).The word "urus" (/ˈjʊərəs/) comes to English from Latin, but may have come to Latin from Germanic origins. It declines in English as "urus" (singular), "uruses" (plural). The Germanic aurochs itself has evolved from the Proto-Indo-European *táwros, just like Ancient Greek ταϋρος (tauros), Latin taurus and Slavic tur (Proto-Slavic: *turъ).

According to the Paleontologisk Museum, University of Oslo, aurochs evolved in India some two million years ago, migrated into the Middle East and further into Asia, and reached Europe about 250,000 years ago. They were once considered a distinct species from modern European cattle (Bos taurus), but more recent taxonomy has rejected this distinction.[citation needed] The South Asian domestic cattle, or zebu, descended from a different group of aurochs at the edge of the Thar Desert; this would explain the zebus' resistance to drought. Domestic yak, gayal and Javan cattle do not descend from aurochs. Modern cattle have become much smaller than their wild forebears. Aurochs were about 1.75 metres (5.7 ft) tall, while a large domesticated cow is about 1.5 metres (4.9 ft) and most domestic cattle are much smaller than this. Aurochs also had several features rarely seen in modern cattle, such as lyre-shaped horns set at a forward angle, a pale stripe down the spine, and sexual dimorphism of coat color. Males were black with a pale eel stripe or finching down the spine, while females and calves were reddish (these colours are still found in a few domesticated cattle breeds, such as Jersey cattle). Aurochs were also known to have very aggressive temperaments and killing one was seen as a great act of courage in ancient cultures.

The recovery pattern of aurochs remains lead to the belief that they preferred swampy and wet wooded areas and, like modern cattle, could swim for short distances enabling them to inhabit islands within their range. Their diet is thought to have consisted of green grass and leaves with occasional tree fruits. Aurochs species were found to have lived on the island of Sicily where once there was a land bridge to Italy. After disappearance of the land bridge, Sicilian aurochs evolved to a size 20% smaller than their mainland relatives. Although the European bison prefers drier forest they would most certainly have lived in areas overlapping aurochs territory. Little else is known about Aurochs habits. Although they survived until the 17th century in Poland they were in competition with modern cattle for food and hunted by humans contributing to their extinction.

Domestication of the aurochs began in the southern Caucasus and northern Mesopotamia from about the 6th millennium BC, while genetic evidence suggests that aurochs were independently domesticated in northern Africa and in India. The modern domesticated cattle descended from the aurochs are so different in size that they have been regarded as a separate species.
Comparison of aurochs bones with those of modern cattle has provided many insights about the aurochs. Remains of the beast, from specimens believed to have weighed more than a ton, have been found in Mesolithic sites around Goldcliff, Wales. Though aurochs became extinct in Britain during the Bronze age, analysis of bones from aurochs that lived in the same age as domesticated cattle there showed no genetic contribution to modern breeds. As a result, modern European cattle are now thought to have descended directly from the Near East domestication event. Indian cattle (zebu), although domesticated eight to ten thousand years ago, are related to aurochs which diverged from the Near Eastern ones some 200,000 years ago. African cattle are thought to descend from aurochs more closely related to the Near Eastern ones.

The Near East and African aurochs groups are thought to have split some 25,000 years ago, probably 15,000 years before domestication. The "Turano-Mongolian" type of cattle now found in Northern China, Mongolia, Korea and Japan may represent a fourth domestication event (and a third event among Bos taurus–type aurochs). This group may have diverged from the Near East group some 35,000 years ago. Whether these separate genetic populations would have equated to separate subspecies is unclear. The original range of the aurochs was from Britain and Ireland and southern Scandinavia, to northern Africa, the Middle East, India and central Asia. By the 13th century A.D., the aurochs' range was restricted to Poland, Lithuania, Moldavia, Transylvania and East Prussia. The right to hunt large animals on any land was restricted to nobles and gradually to the royal household. As the population of aurochs declined, hunting ceased but the royal court still required gamekeepers to provide open fields for the aurochs to graze in. The gamekeepers were exempted from local taxes in exchange for their service and a decree made poaching an aurochs punishable by death. In 1564, the gamekeepers knew of only 38 animals, according to the royal survey. The last recorded live aurochs, a female, died in 1627 in the Jaktorów Forest, Poland from natural causes. The skull was later taken by the Swedish Army during the Swedish invasion of Poland (1655–1660) and is now the property of Livrustkammaren in Stockholm. The causes of extinction were hunting, a narrowing of habitat due to the development of farming, climatic changes and diseases transmitted by domestic cattle.

In the 1920s two German zoo directors (in Berlin and Munich), the brothers Heinz and Lutz Heck, began a selective breeding program in the attempt to breed the aurochs back into existence from the domestic cattle that were their descendants. Their plan was based on the concept that a species is not extinct as long as all its genes are still present in a living population. The result is the breed called Heck cattle, "Recreated Aurochs", or "Heck Aurochs", which bears some resemblance to what is known about the appearance of the wild aurochs.Scientists of the Polish Foundation for Recreating the Aurochs (PFOT) in Poland now want to use DNA from bones of aurochs in museums to recreate the aurochs and return this animal to the forests of Poland. The project has gained the support of the Polish Ministry of the Environment. They plan research on ancient preserved DNA. Similar research projects have been run in the West over the past twenty years and their results published in such periodicals as Nature and Proceedings of the National Academy of Sciences USA. Polish scientists believe that modern genetics and biotechnology make recreating an animal almost identical to aurochs possible (99 percent gene compatibility). They say this research will lead to examining the causes of the extinction of the aurochs, and help in preventing a similar situation occurring among domestic cattle.

Great Auk

The Great Auk, Pinguinus impennis, formerly of the genus Alca, is a bird that became extinct in the mid-19th century. It was the only species in the genus Pinguinus - a group of birds that included several flightless giant auks from the Atlantic Ocean region - to survive until modern times. The Great Auk was also known as a garefowl (from the Old Norse geirfugl, meaning "spear-bird", referring to the shape of its beak) and penguin before the birds known by that name today were so called.The Great Auk was found very extensively on islands off eastern Canada, Greenland, Iceland, Norway, Ireland, and Great Britain before being hunted to extinction. Remains found in Florida suggest that, at least occasionally, the Great Auk ventured that far south in winter as recently as the 14th century.

The Great Auk was one of the many species originally described by Carolus Linnaeus in his 18th century work, Systema Naturae.Analysis of mtDNA sequences have confirmed morphological and biogeographical studies in regarding the Razorbill as the Great Auk's closest living relative. They were also closely related to the Little Auk (Dovekie), which underwent a radically different evolution compared to Pinguinus. Due to its outward similarity to the Razorbill (apart from flightlessness and size), the Great Auk was often placed in the genus Alca. The name Alca is a Latin derivative of the Scandinavian word for razorbills and their relatives. The word impennis in Latin refers to the lack of flight feathers or pennae.The molecular data are compatible with either view, but the weight of evidence suggests placing the Great Auk in a distinct genus.The Basque name for the Great Auk is "arponaz", and in early French, the name was "apponatz", both meaning "spearbill". The Norse called the Great Auk "geirfugl", which means "spearbird". This has led to an alternative common name for the bird, "garefowl". Spanish and Portuguese sailors called the bird "pingüinos". The Inuit (Eskimo) name for the Great Auk was "isarukitsck", which meant "little wing". The Welsh people referred to this species as "pingwen".When European explorers discovered what are today known as penguins in the Southern Hemisphere, they noticed their similar appearance to the Great Auk and named them after this bird.Standing about 75 to 85 centimetres (30 to 33 in) tall and weighing around 5 kilograms (11 lb), the flightless Great Auk was both the largest of the auks and the largest member of the order Charadriiformes. Males and females were similar in size and plumage. The back was primarily a glossy black, while the stomach was white. The neck and legs were short, while the head and wings were small. The auk appeared chubby due to a thick layer of fat necessary for warmth.During the breeding season, the Great Auk developed a wide white eye patch over the eye. However, after the breeding season the auk lost this eye patch and instead a wide white band and a gray line of feathers which stretched from the eye to the ear.The eye had a hazel or chestnut iris. During the summer, the auk's chin and throat were blackish brown. During the winter, this alcid molted and the throat became white. The bill was large at 11 centimetres (4.3 in) long and curved downwards at the top. There were deep white grooves in both the upper and lower mandibles of the bill. The wings were only 15 centimetres (5.9 in) in length and the longest wing feathers were only 10 centimetres (3.9 in) long. Its feet and claws were black while the webbed skin between the toes was brownish black. The legs were far back on the bird's body to give it more powerful swimming and diving abilities. Juvenile birds had less prominent grooves in their beaks and had mottled white and black necks.

The Great Auk was found in the cold North Atlantic coastal waters along the coasts of Canada, the northeastern United States, Norway, Greenland, Iceland, Ireland, and Great Britain. The Great Auk left the North Atlantic waters for land only in order to breed. The rookeries of the Great Auk were found from Baffin Bay down to the Gulf of St. Lawrence, across the far northern Atlantic, including Iceland, and in Norway and the British Isles in Europe. The Great Auk's nesting colonies required rocky islands with sloping shorelines to provide the birds access to the seashore. This was an extremely limiting factor and it is believed that the Great Auk may never have had more than 20 breeding colonies. Only eight breeding colonies are known: Papa Westray in the Orkney Islands, St. Kilda Island off Scotland, the Faeroe Islands between Iceland and Ireland, Grímsey Island and Eldey Island near Iceland, Penguin Island and Funk Island near Newfoundland, and the Bird Rocks (Rochers-aux-Oiseaux) in the Gulf of St. Lawrence. Additionally, records suggest that this species may have bred on Cape Cod, Massachusetts. By the late 1700s and early 1800s, the living range of the Great Auk were restricted to Funk Island, Grimsey Island, Eldey Island, the Gulf of St. Lawrence, and St. Kilda Island.The Great Auk migrated south in the winter. Its bones have been found as far south as Florida and Gibraltar, while it frequented France, Spain, and even Italy in the Mediterranean Sea.

Great Auks walked slowly and sometimes used their wings to help them traverse rough terrain. They had few natural predators, mainly large marine mammals (such as the walrus and the orca, and birds of prey, and the Great Auk had no innate fear of human beings. Polar bears preyed on nesting colonies of the auk. Their flightlessness and their awkwardness on land compounded their vulnerability to human beings, who hunted them for food, feathers, and as specimens for museums and private collections. The Great Auk reacted to noises, but were rarely scared by the sight of something. The Great Auks were believed to have had a life span of about 20 to 25 years.The Great Auk was generally an excellent swimmer, using its wings to propel itself underwater. These great birds were capable of banking, veering, and turning underwater. The Great Auk was known to dive to depths of 76 metres (250 ft) and it has been claimed to be able to dive to 1 kilometre (3,300 ft). It could also hold its breath for 15 minutes, longer than a seal. The Great Auk was capable of swimming rapidly to gather speed, then shooting out of the water and landing on a rocky ledge not level with the ocean.During the winter, the Great Auk migrated south either in pairs or in small groups, and never with the entire nesting colony.

This species is estimated to have had a maximum population in the millions, although some scientists dispute this estimation. The Great Auk was hunted on a significant scale for food, eggs, and its down feathers from at least the 8th century. Prior to that, hunting by local natives can be documented from Late Stone Age Scandinavia and Eastern North America, and from early 5th century Labrador where the bird seems to have occurred only as a straggler. Early explorers, including Jacques Cartier and numerous ships attempting to find gold on Baffin Island, were not provisioned with food for the journey home, and therefore they used this species as a handy food source. Some of the later vessels anchored next to a colony and ran out planks to the land. The sailors then herded hundreds of the Auks onto the ships, where they were then slaughtered.

The Little Ice Age may have reduced the population of the Great Auk, but massive exploitation for their down drastically reduced the population. By the mid-1500s, the nesting colonies along the European side of the Atlantic were nearly all eliminated by individuals killing this bird for its down, which was used to make pillows. In 1553, the auk received its first official protection, and in 1794 London banned the killing of this species for their feathers. On the North American side, eider down was initially preferred, but once the eiders were nearly driven to extinction in the 1770s, down collectors switched to the auk. Specimens of the Great Auk and its eggs became collectible and highly prized, and collecting of the eggs contributed to the demise of the species.

It was on the islet of Stac an Armin, St Kilda, Scotland, in July 1840, that the last great auk seen in the British Isles was caught and killed. A then 75-year-old inhabitant of St Kilda told Henry Evans, a frequent visitor to the archipelago, that he and his father-in-law with another man had caught a "garefowl", noticing its little wings and the large white spot on its head. They tied it up and kept it alive for three days, and then killed it by beating it with a stick, apparently because they believed it to be a witch. Eggers, individuals who visited the nesting sites of the Great Auk to collect their eggs, quickly realized that the birds did not all lay their eggs on the same day, so they could make return visits to the same breeding colony. Eggers only collected eggs without embryos growing inside of them and typically discarded the eggs with embryos.

The last colony of Great Auks lived on Geirfuglasker (the "Great Auk Rock") off Iceland. This islet was a volcanic rock surrounded by cliffs which made it inaccessible to humans, but in 1830 the islet submerged, and the birds moved to the nearby island of Eldey, which was accessible from a single side. When the colony was initially discovered in 1835, nearly fifty birds were present. Museums, desiring the skins of the auk for preservation and display, quickly began collecting birds from the colony. The last pair, found incubating an egg, were killed there in July 1844, with Jón Brandsson and Sigurður Ísleifsson strangling the adults and Ketill Ketilsson smashing the egg with his boot. However, a later claim of a live individual sighted in 1852 on the Grand Banks of Newfoundland has been accepted by the International Union for Conservation of Nature and Natural Resources (IUCN).

Today, around 75 eggs of the Great Auk remain in museum collections, along with 24 complete skeletons and 81 mounted skins. While thousands of isolated bones have been collected from 19th century Funk Island to Neolithic middens, only a small number of complete skeletons exist.

Cave Lion

The cave lion (Panthera leo spelaea) also known as the European or Eurasian cave lion, is an extinct subspecies of lion known from fossils and multiple examples of prehistoric art.This subspecies was one of the largest lions. An adult male, which was found in 1985 near Siegsdorf (Germany), had a shoulder height of around 1.2 m (4 ft) and a body length of 2.1 m (7 ft) without tail. This is similar to the size of a very large modern lion. The size of this male has been exceeded by other specimens of this subspecies. Therefore this cat may have been around 5-10% bigger than modern lions, but it didn't reach the measures of the earlier cave lion subspecies Panthera leo fossilis or those of the huge American lion (Panthera leo atrox). The cave lion is known from Paleolithic cave paintings, ivory carvings, and clay figurines. These representations indicate that cave lions had rounded, protruding ears, tufted tails, possibly faint tiger-like stripes, and that at least some had a "ruff" or primitive mane around their neck, indicating males. Other archaeological artifacts indicate that they were featured in Paleolithic religious rituals.

The cave lion received its common name from the fact that large quantities of its remains are found in caves , but it is doubtful whether they lived in them. It had a wide habitat tolerance, but probably preferred conifer forests and grasslands , where medium-sized to large herbivores occurred. Fossil footprints of lions, which were found together with those of reindeer, demonstrate that these cats once occurred even in subpolar climates. The presence of fully articulated adult cave lion skeletons, deep in cave bear dens, indicates that lions may have occasionally entered dens to prey on hibernating cave bears, with some dying in the attempt.These active carnivores probably preyed upon the large, herbivorous animals of their time, including horses, deer and bison. Some paintings of them in caves show several hunting together, which suggests the hunting strategy of contemporary lionesses.

Small prey was usually brought down with a blow of the front paw and then held down with both front feet. The animal was finally killed by a powerful bite of the sharp teeth , at the back of the neck, in the region of the throat and even in the chest. A cave lion usually could not run as fast as its prey, but could pounce on it from behind or run up next to it and bring it down with the paws. In this manner a running animal's balance could very easily be disturbed. It was most likely the most common predator (after the cave hyena) in plains ecosystems. Its extinction may have been related to the Quaternary extinction event, which wiped out most of the megafauna prey in those regions. Cave paintings and remains found in the refuse piles of ancient camp sites indicate that they were hunted by early humans, which also may have contributed to their demise.

The cave lion is considered a species in its own right, under the name Panthera spelaea, and at least one authority, based on a comparison of skull shapes, considers the cave lion to be more closely related to the tiger, which would result in the formal name Panthera tigris spelaea. However, recent genetic research shows that it was a close, but separate, relative of the modern lion and leopard.

The cave lion (Panthera spelea) was derived from the earlier Panthera leo fossilis, which first appeared in Europe about 700,000 years ago. The cave lion itself lived from 370,000 to 10,000 years ago, during the Pleistocene epoch. Apparently, it became extinct about 10,000 years ago, during the Würm glaciation, although there are some indications it may have existed into historic times in southeastern Europe, as recently as 2,000 years ago in the Balkans. Cave lions were widespread in parts of Europe and Asia, from Great Britain, Germany and Spain (Arduini & Teruzzi, 1993) all the way to the Bering Strait and from Siberia to Turkistan.