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Extinct animals
Extinction, in ecology, refers to the end of a specific group of organisms. Simply put, the death of the last individual of a particular species is considered the moment of extinction of that species. Over the years, the planet has witnessed the extinction of several species--right from tiny frogs to huge dinosaurs. While some of these animals fell prey to mass extinctions, others were slowly brought to the brink of extinction by humans, and eventually wiped off the planet.
It is estimated that around 99 percent of the animals to have ever existed on Earth are extinct today. Though the concept of extinction is not new for the planet, the alarming rate at which animals are disappearing over the last century or so, has left the scientists worried. At the ongoing rate, we are set to lose some of the most important species in the ecosystem, which, in turn, will result in severe ecological imbalance and bring about the downfall of all the plants and animals related to that particular species. More importantly, we need to understand that we are a part of this ecosystem and therefore, the loss of any species is bound to affect us directly or indirectly, sooner or later!

Note: It is very difficult to figure out the exact moment at which the animal became extinct, and therefore, the concerned organizations have to wait for a significant period after the last sighting to declare it extinct. Simultaneously, thorough research is carried out to ascertain whether the species has really become extinct or it still exists in the wild.

The western black rhinoceros, for instance, was declared extinct in 2011, i.e., almost a decade after the last sighting, when all attempts to find it in the wild failed. If the species is not found in the wild, but is extinct in captivity, it is enlisted as Extinct in the Wild (EW).
How Did They Become Extinct
In the following section, we will take a look at the animal extinctions which occurred in the last 100 years, along with some information on what triggered the extinction of these species. Going through the list will help us realize how we were--directly or, indirectly--responsible for the tremendous loss our planet has faced over the years. If at all we do end up learning from our mistakes, we will be in a better position to do our bit for the environment and save several hundreds of animals and plants which are threatened with extinction.
Cape Verde Giant Skink
Cape Verde Giant Skink (Macroscincus coctei), also known as the Cocteau's Skink, was a reptile endemic to the Cape Verde Islands in the Atlantic Ocean. Human encroachment and the resultant loss of habitat was the major factor responsible for the extinction of this skink species. They were hunted extensively for food and 'skink oil' in the beginning of the 20th century.
Some sources also suggest that the prolonged drought that hit the region during this period led to their extermination from the Cape Verde Islands. Though the species was last sighted in 1912, it was officially declared extinct only in 2013 after all the attempts to find it in its rocky habitat failed to yield desired result.
Canarian Black Oystercatcher
The Canarian Black Oystercatcher (Haematopus meadewaldoi), often referred to as the Canary Islands Oystercatcher, was a shorebird which was found on the Canary Islands of Spain. It is believed that the disturbance by locals and extensive predation by rats triggered the extinction of this species in the beginning of the 20th century. There also exist theories which suggest that it was the loss of habitat that was responsible for its extinction.
The last confirmed sighting of the Canarian Black Oystercatcher came in 1913. Unverified accounts of sighting by the local fishermen and the lighthouse keepers continued to come till 1940s. After several attempts to find this Oystercatcher species failed, it was eventually declared extinct by the International Union for Conservation of Nature (IUCN) in 1994.
Laughing Owl
The Laughing Owl (Sceloglaux albifacies), also referred to as the White-faced Owl, was endemic to New Zealand. The extinction of this species was triggered by several factors, including the use of this species as lab specimen, loss of habitat due to land use changes, and the introduction of predators in form of cats and dogs.
With all these factors coming into play, its population began to decline towards the last quarter of the 19th century. In fact, the laughing owl was virtually gone by 1880. The last confirmed sighting of the Laughing owl came from Canterbury, New Zealand, on July 5th, 1914, in form of a dead specimen found at the Bluecliffs Station. While ornithologists are hopeful about the existence of this species, there is no concrete evidence to support the claim.
Passenger Pigeon
The most common bird in North America at one point of time, the Passenger Pigeon (Ectopistes migratorius) is only found in the IUCN's extinct animals list today. In the 19th century, large migratory flocks of Passenger Pigeons, each containing thousands of birds, were commonplace. That, however, changed with the arrival of Europeans on the continent who hunted the species for food.
Other than extensive hunting, first, by the Native Indians, and then, by the European settlers, the species also had to bear the brunt of habitat destruction; courtesy, large-scale deforestation by the European settlers. Extensive hunting and loss of habitat led to a drastic decline in the population of this species; only a few sightings were recorded during the first decade of the 20th century. The Passenger Pigeon eventually became extinct with the death of the last specimen, Martha, at the Cincinnati Zoo on 1st September, 1914.
Carolina Parakeet
The lone species of parrot, native to the eastern United States, the Carolina Parakeet (Conuropsis carolinensis) was found in the forested areas ranging from the Ohio Valley to the Gulf of Mexico. Of the numerous reasons for the decline and eventual extinction of this species, the most prominent was perhaps the loss of habitat due to the clearing of large tracts of forests for agricultural purposes.
The population of the Carolina parakeet also declined due to extensive hunting for their colored feathers, which were used for decoration, and large-scale culling executed by farmers, who considered them pests. Some theories which suggest that the introduction of honey bees and a mysterious poultry disease contributed to the extinction of these beautiful birds also exist. The last Carolina Parakeet in the wild was killed in Florida in 1904, while the last individual in captivity died in the Cincinnati Zoo in 1918.
Barbary Lion
The Barbary lion (Panthera leo leo), also known as the Atlas lion or Nubian lion, was a subspecies of lion, native to the Northern regions of Africa. Weighing between 440 to 600 lbs, the Barbary lion was considered the heaviest of the lion subspecies. Large-scale hunting and capturing for captive use caused the Barbary lion population in the wild to decline drastically. Loss of habitat due to the expansion of agricultural lands also contributed to the extinction of this species.
Records suggest that the last Barbary lion was killed in the Atlas Mountains in 1922. Initially declared extinct, the animal was later given the special status - 'extinct in the wild' (EW) by the IUCN as a few were thought to be alive in captivity in zoos and circuses. However, it is still not clear whether these captive lions are actually Barbary lions or not.
Bubal Hartebeest
The Bubal Hartebeest (Alcelaphus buselaphus buselaphus) was an antelope species found in African countries, like Algeria, Egypt, Libya, Morocco, and Tunisia. The species was quite popular in ancient Egypt, wherein it was domesticated and, according to some sources, even used as a sacrificial animal. The last reliable sighting in the wild came in 1902, while the last known Bubal Hartebeest in captivity died at a zoo in Paris in 1923.
In the 19th century, the region was reduced to a war zone as a result of the French expedition in Africa. During the period, large herds of the Bubal Hartebeest were killed by the army. By the beginning of 20th century, the population of Bubal Hartebeest depleted to a great extent. It was only found in Algeria and Morocco. In the beginning of the 20th century, a large number of hartbeests were either hunted or captured and kept in the zoos (where they died as they were not able to adapt to captive conditions.
Caucasian Wisent
The Caucasian wisent ((Bison bonasus caucasicus) was a subspecies of wisent, i.e., the European bison, native to the Caucasus mountains in eastern Europe. Until the 17th century, the only threat for this species came from predators, like the Caspian tigers, Asiatic lions, wolves, etc. Over the course of time, however, human settlements in these mountains increased, which adversely affected the range of this species.
At the same time, this Caucasian wisent was confronted by a new threat in the form of poaching. Loss of habitat and excessive poaching
depleted the wisent population to a great extent, with the numbers falling to less than 600 by 1917 and further down to less than 50 by 1921. The failure to curb poaching eventually resulted in the extinction of the Caucasian wisent, with the last reported individual being killed in 1927.
Crescent Nail-tail Wallaby
The Crescent nail-tail wallaby (Onychogalea lunata) was a subspecies of the nail-tail wallaby, which inhabited the woodlands and scrubs of western and central Australia. Though the species was found in abundance in Western Australia until the 20th century, that changed with human encroachment in this region. The last sighting of this species came in the form of an individual caught in a dingo trap in 1927.
Within a decade of human settlement, the wallaby population witnessed a steep decline, primarily due to predation by newly introduced species and land conversion. While large-scale conversion of wild areas into pastoral lands resulted in habitat fragmentation, the introduction of rabbits increased the competition for food. Though rare, the sightings of Crescent nail-tail wallaby continued through the first half of the 1920s. The species did survive in the wild till the 1950s, but the spread of the red fox came as a final blow, and resulted in the extinction of this species.
Paradise Parrot
The Paradise Parrot (Psephotus pulcherrimus) was a colorful medium-sized parrot native to the Queensland-New South Wales border region of northeastern Australia. Several factors contributed to the extinction of this species; most prominent among these were the loss of habitat due to over grazing, clearance of land for agriculture, extensive hunting by bird collectors, and predation by several species of cats.
Rare sightings aside, the species had virtually disappeared from this region by 1915. A few more sightings were recorded over the next decade or so, and eventually, the species became extinct with the last confirmed sighting coming on 14th September, 1927.
Syrian Wild Ass
The Syrian Wild Ass (Equus hemionus hemippus) was a subspecies of the onager (Equus hemionus), which was found in the Middle East; Syria, Jordan, Iraq, etc. The species was seen in large herds all throughout the 15th and 16th centuries, but excessive hunting over the course of the next few decades brought about a drastic decline in their numbers.
By the 18th century, the large herds of the Syrian Wild Ass had virtually disappeared. The final blow for the species came in the form of World War I, wherein armed humans killed the species in large numbers. A specimen killed in Jordan in 1927 was believed to be the last Syrian Wild Ass in the wild, while the one which died at the Vienna zoo--that very year--turned out to be the last in captivity.
Thick-billed Ground-Dove
The Thick-billed Ground Dove (Gallicolumba salamonis) was a dove species native to the Solomon Islands. Interestingly, the existence of this species was only known due to the two specimens that were recorded, first in 1882 and second in 1927. Being a ground-dwelling species, the Thick-billed Ground Dove was vulnerable to introduced species like rats, cats, dogs, and feral pigs.
The species was also affected by habitat loss due to logging, which was a thriving industry in this region, and large-scale hunting during World War II. The bird was last seen in 1927--only the second sighting of the species, and was officially declared extinct 78 years later in 2005.
Darwin's Galapagos Mouse
Darwin's Galapagos Mouse (Nesoryzomys darwini) was a rodent native to the Santa Cruz Island of the Galapagos group. It was discovered in 1906 and last seen in 1930, and therefore, it doesn't come as a surprise that very little is known about it. It is believed that the introduction of black and brown rats in this region resulted in loss of the species as they were forced to compete not only with these alien species, but also had to deal with the diseases brought in by them.
Heath Hen
The Heath hen (Tympanuchus cupido cupido) was a subspecies of the Greater Prairie-Chicken, which was found in the heathland barrens of coastal New England. This species was found in abundance during the colonial regime, but extensive hunting--for food in particular--brought about a drastic fall in their number, and by mid-19th century the bird became extinct from the mainland.
Only a few hundred heath hens were left on the island off Massachusetts. The establishment of Heath Hen Reserve did help in reviving their population, which reached around 2000 individuals towards the first quarter of the 20th century, but severe winter, excessive predation by species such as goshawks, destructive fires, inbreeding, and blackhead disease eventually resulted in the extinction of this species. It was the first bird which the U.S. authorities had tried to save, but sadly, their attempt didn't yield the desired results and the Heath hen became extinct with the death of last individual in 1932.
Hawai'i 'O'o
The Hawai'i 'O'o (Moho nobilis) was a member of the Mohoidae family of birds, and was found in abundance on the island of Hawaii. It was one of the most beautiful species on the Island of Hawaii. Sadly, the striking plumage of Hawai'i 'O'o turned out to be a curse for the species, as it was hunted extensively for its feathers, which were used in decorations.
It was also caught and sold as a song bird, but that turned out to be even more disastrous as most of the individuals, unable to adapt to the captive conditions, died within a week of being caught. The introduction of musket gave a boost to hunting, and the Hawai'i 'O'o had virtually become extinct by the end of the 19th century - with rare sightings once in a while. The last of these sightings came from Mauna Loa, a volcano on south central Hawaiian Island in 1934.
Indefatigable Galapagos Mouse
The Indefatigable Galapagos Mouse (Nesoryzomys indefessus), also known as the Santa Cruz Nesoryzomys, was a small rodent found on the island of Santa Cruz of the Galapagos group of islands. Not much is known about this species, leave alone its extinction. It is believed that the introduction of the black rat triggered the extinction of the Indefatigable Galapagos Mouse, firstly by increasing the competition for food, and secondly by bringing in diseases.
The last specimen was collected in 1934, but the species was declared extinct only in 2000. Though some sources consider Nesoryzomys indefessus narboroughi a subspecies of the Indefatigable Galapagos Mouse, experts are of the opinion that it's a different species.
Desert Rat Kangaroo
The desert rat-kangaroo (Caloprymnus campestris), also known as the buff-nosed rat-kangaroo or plains rat-kangaroo, was a small marsupial, native to the deserts of Central Australia.
After the initial sightings in 1840s, the species was not seen for almost 90 years and was thought to have become extinct. In 1931, however, a colony of desert rat-kangaroo was found in the arid parts of this region. The species was never found in large numbers to begin with. The introduction of the red fox further added to their woes as the canine invaded their native habitat and preyed on them. So the combined effects of the introduced predators and habitat destruction by the colonizers contributed to the extinction of desert rat kangaroos. Unconfirmed sightings aside, the species was not seen after 1935 and was eventually declared extinct in 1994.
Ryukyu Wood Pigeon
The Ryukyu Wood Pigeon (Columba jouyi) was a pigeon subspecies endemic to the Okinawa archipelago lying towards the southwest of the Japanese mainland. Its extinction was triggered by habitat destruction when the tropical forests, which were home to this species, were subjected to large-scale deforestation for agricultural and settlement purpose.
Along with human settlement, in came the practice of hunting, and that resulted in further decline of the Ryukyu Wood Pigeon population by the first decade of the 20th century. By 1930s, these islands were completely deforested, and the resultant habitat loss led to the extinction of the Ryukyu wood-pigeon. The last sighting of the species came from the Daito group of islands in 1936.
Tasmanian Wolf
The Thylacine (Thylacinus cynocephalus), more often referred to as the Tasmanian tiger or the Tasmanian wolf, was native to the continental Australia, Tasmania, and New Guinea. Being the last member Thylacinus genus, the extinction of Tasmanian Wolf in 1936 marked the extinction of this genus itself.
The most prominent factors which led to the extinction of this animal were extensive hunting, introduction of dogs, and human encroachment. Though debatable, spread of diseases was yet another factor which supposedly played a vital role in its extinction. The last known sighting of the Tasmanian wolf in the wild was recorded in 1930, when a local farmer killed one specimen in Mawbanna. On the other hand, the last known Tasmanian wolf specimen in captivity died in 1936.
Bali Tiger
The Bali tiger (Panthera tigris balica), native to the small island of Bali in Indonesia, is one of the three tiger subspecies which are not found on the planet anymore; others being the Javan tiger and Caspian tiger. Like a whole lot of species from this region, even the Bali tiger succumbed to habitat fragmentation caused due to large scale deforestation.
Other than the loss of habitat, extensive hunting of this species, especially during World War II, had a serious impact on its population. By the end of World War II, the Bali tiger was virtually extinct. The last documented sighting of this species came in September 1937, when an adult female was killed in West Bali. It was officially declared extinct by the IUCN only in 2008.
Grand Cayman Thrush
The Grand Cayman thrush (Turdus ravidus) was a true thrush, endemic to the Grand Cayman Island--the largest of the three Cayman Islands. Immediately after its discovery, this beautiful bird became a sought-after species for bird collectors in this region. The last reported sighting of this species came from the north of East End in 1938.
Between 1932 and 1944, the habitat of Grand Cayman thrush was affected by excessive deforestation and frequently occurring hurricanes. Loss of habitat made them an easy prey for hunters and bird collectors alike. By the end of the first quarter of the 20th century, the bird had virtually become extinct. As of today, only the stuffed remains of this species can be seen in various museums of the world.
Schomburgk's Deer
The Schomburgk's deer (Rucervus schomburgki) was a species native to Thailand, which was known particularly for its magnificent antlers. Sadly, the beauty of this animal turned out to be the prime reason for its extinction as the species was killed in large numbers for its sought-after antlers. The spread of Chinese medicine further added to its woes as the alleged medicinal properties of its antlers made them a key ingredient in alternative medicine.
Yet another threat came in form of habitat loss as large tracts of forests were cleared for agricultural purposes. Found in abundance at one point of time, the species had virtually become extinct by 1920. The last sighting in the wild came in 1932, while the last captive specimen was killed in 1938. In 1991, the antlers recovered from a Chinese medicine shop in Laos did give some hope about the existence of this species in the wild, but that turned out to be a false alarm.
Roque Chico de Salmor Giant Lizard
The Roque Chico de Salmor giant lizard (Gallotia simonyi simonyi) was a subspecies of the wall lizard, which was endemic to a small islet in the Canary Islands. The species was affected by human encroachment in its native habitat in the beginning of the 20th century.
Initially, the only threat for this species was predation by feral cats and herring gulls, but human intervention turned out to be even more disastrous. It not only resulted in loss of habitat for the species, but also made it vulnerable to commercial exploitation wherein the lizards were collected in large numbers and used in scientific experiments. All these factors combined led to the depletion of the Roque Chico de Salmor Giant Lizard population. Attempts to revive the population were initiated, but they came too late and the species disappeared somewhere in the late 1930s.
Desert Bandicoot
The desert bandicoot (Perameles eremiana) was endemic to western and central Australia, wherein it inhabited the sandy desert with sphinifex vegetation. The animal was common in this region until 1930s, but the sightings decreased as habitat destruction began to take its toll on the species.
Other than the wildfires caused by lightning strikes, overgrazing by rabbits also brought about a great deal of destruction in this region. The introduction of red fox is also considered one of the trigger factors responsible for the extinction of the desert bandicoot. The last sighting came in form of a specimen collected from Western Australia in 1943.
Toolache wallaby
The Toolache wallaby (Macropus greyi), also referred to as the Grey's wallaby, was a wallaby subspecies native to the Australian provinces of South Australia and Victoria. Extensive hunting was one of the prominent factors which led to the extinction of this species from the Australian continent.
Back then, wallaby hunting was a popular sport in this region and the local hunters hunted them extensively for trophies. The animal was also hunted in large numbers for its fur. Other factors responsible for the extinction of the Toolache wallaby were predation by foxes and loss of habitat as a result of the conversion of land into pastures. Owing to all these factors, the Toolache wallabies, which were once common in Australia, became very rare by 1920s. After the attempts to capture and transfer them to safer sanctuaries failed, the species eventually became extinct - with the last sighting coming in 1943.
Laysan Rail
The Laysan Rail (Porzana palmeri), also referred to as the Laysan Crake, was a tiny bird that inhibited the Laysan Island of the Hawaii group. There were around 2000 matured birds on the island in 1910, but within 13 years, i.e., by 1923, this number dropped to less than 10. Introduction of rabbits and guinea pigs was one of the prominent factors responsible for the extinction of the Laysan rail.
With no predators to keep a check on the rabbit population, they went rogue and finished off the vegetation. This, in turn, resulted in loss of habitat for the rail species. Attempts to revive the Laysan rail population were put in place, and just when there was a slight hope of revival, a US Navy landing craft accidentally broke free and drifted to islands bringing with it a whole lot of rats which colonized the island. Predation by these rats, which seemed particularly fond of Laysan rail eggs, came as a final blow for the population. The last sighting of Laysan rail was reported from the Eastern Island in June 1944.
Wake Island Rail
The Wake Island Rail (Gallirallus wakensis) was a flightless bird endemic to the island of Wake in the Pacific Ocean. This land bird was found in abundance in its natural habitat, before World War II broke out. The Japanese forces who occupied the island were cut off from food supply during the war. The Wake Island Rail being a flightless bird became an easy victim for them and was killed for food. This affected its population and the species became extinct by 1945.
Thicktail Chub
The thicktail chub (Gila crassicauda) was a small freshwater fish that inhabited the lowlands and weedy backwaters of Sacramento and San Joaquin rivers in California. It was one of the most common fish in California and in fact, constituted approximately 40 percent of the fish population of the Sacramento river. The Thicktail Chub's extinction was triggered by habitat loss due to the conversion of a large part of land in Central Valley for agricultural use.
Dam building, water diversion, and other such agricultural projects led to a decline in the fish population as well. Furthermore, competition with exotic species and hybridization blurred the chances of recovery, and the Thicktail Chub became extinct in late 1950s.
Caribbean Monk Seal
The Caribbean monk seal (Monachus Tropcalis), also known as the West Indian monk seal, was a species of seal native to the Caribbean Sea and Gulf of Mexico. Known for their docile nature, these seals were hunted mercilessly in the 18th and 19th century for their products.
At the same time, overfishing in this region left these seals with nothing to feed on and this food scarcity eventually contributed to their extinction. The last recorded sighting of the Caribbean monk seal was at the Serranilla Bank in the western Caribbean Sea in 1952. It is the only seal species that has been driven to extinction by human activities.
Little Swan Island Hutia
The Little Swan Island hutia (Geocapromys thoracatus) was a guinea-pig-like rodent native to the Swan Islands of the Caribbean. It was a slow moving creature which left the caves and lime stone crevices to feed on barks, twigs and leaves. Once found in abundance on the island, the species became relatively rare towards 1950s and literally disappeared after a hurricane destroyed their natural habitat in 1955.
Some sources suggest that it was a subspecies of Jamaican Hutia, supposedly brought to Swan Islands from Jamaica. The first blow to the Little Swan Island Hutia population came when the newly introduced house cats began predating on this species. With no sightings of the Little Swan Island Hutia since 1955, it was officially declared extinct by the IUCN in 1996.
Caspian Tiger
The Caspian tiger (Panthera tigris virgata), also referred to as the Persian tiger, was a subspecies of the Siberian tiger native to Western and Central Asia. Habitat loss caused by the conversion of reed forests into agricultural land and large-scale hunting of wild pigs, which formed an important constituent of their diet, contributed to their decline and eventual extinction.
The extinction of this species can be attributed to several other factors. Among these factors, the most prominent factor would be the large-scale extermination of these tigers by the Russian administration in the beginning of the 20th century in the garb of land reclamation program. As far as the last sighting of Caspian tiger is concerned, different accounts suggest different dates--ranging from 1940s to as recent as 1997, but most of the sources say that the species became extinct somewhere in the 1950s. The Caspian tiger was enlisted as an extinct species only in 2003.
South Island Piopio
The South Island Piopio (Turnagra capensis), also known as the New Zealand Thrush, was a passeriform bird endemic to New Zealand. Though the bird was found in abundance at one point of time, its population began to decline rapidly towards the last quarter of the 19th century, mainly as a result of predation by rats and cats which were introduced to the island by humans.
By the last decade of the 19th century, the South Island Piopio had become the rarest bird in the country. Rare sightings continued for the few decades to follow, before the species finally became extinct. The last confirmed sighting of the South Island Piopio was recorded in 1963.
Santo Stefano Lizard
The Santo Stefano lizard (Podarcis sicula sanctistephani) was a small lizard species native to the Santo Stefano Island in the Tyrrhenian sea, off the coast of Italy. The extinction of this lizard species was triggered by the large-scale predation by feral cats and snakes that were introduced to this island.
While that brought about a drastic decline in their population, the few individuals that survived the predators eventually succumbed to an epidemic that broke out in the mid-20th century. It only took the introduction of some predators and an epidemic to finish the entire Santo Stefano lizard population within a few years. The last confirmed sighting of this lizard species was recorded in 1965 and it was eventually declared extinct.
Arabian Ostrich
The Arabian Ostrich (Struthio camelus syriacus), also referred to as the Middle Eastern Ostrich, was a subspecies of ostrich, native to the Arabian Peninsula. It was the widespread introduction of firearms in the 19th century that triggered the extinction of this flightless bird by making hunting an easy task.
By the beginning of 20th century, the Arabian Ostrich had become a relatively rare species, and by mid-20th century, it virtually vanished. The last recorded sighting of this ostrich subspecies can be traced to 1966, when a dying individual was found near Petra, Jordan.
Guam Flying Fox
The Guam flying fox (Pteropus tokudae), also referred to as the Guam fruit bat, was a small megabat found in Guam. Considered a delicacy in Marianas, this species of fruit bat was extensively hunted as a food source. While large-scale hunting for food resulted in a severe decline in the population of this species, loss of habitat during World War II and the introduction of brown tree snakes led to the extermination of the Guam flying fox from the island.
With no conservation measures in place, their population continued to dwindle, and the species was virtually extinct by mid-20th century. The last confirmed sighting of Guam flying fox came from Tarague cliff in 1967.
Tecopa pupfish
The Tecopa pupfish (Cyprinodon nevadensis calidae) was a subspecies of the Amargosa pupfish, endemic to the hot springs in the Mojave Desert of California. The species was mainly affected by the recreational development of the Tecopa Hot Springs in 1950s.
While habitat loss was already a problem, the competition posed by introduced species, like the bluegill and western mosquitofish, further added to their woes. The last confirmed sighting of the Tecopa pupfish came in form of a specimen collected on February 2, 1970. With no further sightings, the species probably became extinct the very next year. The Tecopa pupfish was the first species to be declared officially extinct under the Endangered Species Law 1973.
Bushwren
The Bushwren or Bush Wren (Xenicus longipes) was a small ground-nesting bird endemic to New Zealand. It was found in abundance throughout New Zealand initially, but the introduction of mustelids in the 19th century changed the picture. Their population declined significantly as a result of extensive predation by mustelids.
The first half of the 20th century was marked by rare sightings of the species. (A subspecies of the bird, the Stead's Bushwren, found on Stewart Island, became extinct in 1951 due to excessive predation by feral cats.) As a last attempt to revive the population, six Bushwrens were transferred to Kaimohu Island, but they failed to adjust to the new environment and eventually died in 1972.
Javan Tiger
Javan tiger (Panthera tigris sondaica) was a subspecies of tiger, which was endemic to the island of Java in Indonesia. The animal was found on the island of Java in large numbers during the 18th century, but things changed drastically over the course of time as human encroachment resulted in habitat loss for this species.
Like the Bali tiger, even the Javan subspecies was hunted extensively during the beginning of the 19th century. Other than loss of habitat, the depleting forest cover also resulted in overlapping territories with leopards and wild dogs, and fueled the competition for available resources. Only around 25 Javan tigers were surviving in the wild in the 1950s, but no efforts were taken to save them. The number continued to decline and eventually resulted in extinction of the Javan tiger with the last confirmed sighting coming in 1972.
Japanese Sea Lion
The Japanese sea lion (Zalophus japonicus) was a sea lion native to the coastal areas of Japanese Archipelago and the Korean peninsula. The species was exploited on a large scale for its skin and oil, which was in high demand in the international market.
Some internal organs of the Japanese sea lion were also used in Oriental medicine and therefore, were in great demand. Overfishing of the species brought their number to less than 300 in 1915, and down to just a few dozens by 1930. Other reasons for the extinction of Japanese sea lions were loss of habitat, due to submarine warfare in World War II, and capturing of the species for circus trade. The last colony of these sea lions was seen in 1950s, while the last confirmed sighting was recorded in 1974.
Round Island Burrowing Boa
The Round Island Burrowing Boa (Bolyeria multocarinata) was endemic to the Round Island off the northern coast of Mauritius. A species with limited distribution is most vulnerable to extinction; the Round Island Burrowing Boa is perhaps the best example of this. The last sighting of this species was recorded in 1975.
It was found over a small area of hardwood forests and palm Savanna on the Round Island. Overgrazing by herbivores, like rabbits and goats, resulted in soil erosion, which, in turn, resulted in loss of habitat for this species. By the end of the first half of the 20th century, the Round Island Burrowing Boa had already reached the brink of extinction. Rare sightings continued for some time before the species finally disappeared.
Colombian Grebe
The Colombian grebe (Podiceps andinus) was an aquatic bird native to the Bogota wetlands of Colombia. The population of this grebe subspecies was largely hit by loss of habitat and predation. Wetland drainage, siltation, and reed harvesting led to the destruction of the Colombian grebe habitat.
At the same time, the predation by rainbow trouts and hunting by humans also affected the Colombian grebe population in this area, which came down to about 300 by 1968. With no conservation efforts in place, their population dwindled further with only a few sightings reported in the 1970s; the last of which came in 1977. Attempts to find Colombian grebes in the wild continued until 1982, but none of these yielded positive results.
Mariana Mallard
The Mariana Mallard (Anas oustaleti) was a water bird endemic to the Mariana Islands of the Pacific Ocean. It was one of the numerous species that had to bear the brunt of human activities in their native habitat. The species faced habitat loss when the wetlands on the island were drained to recover land for agriculture and construction.
Along with that, even the pollution of water bodies contributed to the extinction of this species by introducing a number of harmful chemicals in its food chain. The final blow came in the form of over-hunting, and flocks became very rare by the 1940s. In 1979, the authorities tried to breed the species in captivity, but failed miserably and the Mariana Mallard became extinct with the death of the last specimen in 1981.
Formosan Clouded Leopard
The Formosan clouded leopard (Neofelis nebulosa brachyura) was a subspecies of the clouded leopard, which was endemic to the dense tropical forests on the island of Taiwan. The species came directly under threat when its natural habitat was destroyed with cited reasons of logging. The last sighting of the species came from the Tawu Mountain region back in 1983.
Other than habitat loss--courtesy large-scale deforestation--this leopard was also affected by rampant poaching. Like the extinct big cats, even the Formosan clouded leopards were killed in large numbers for their skin and bones, which have a huge demand in the international market. After searching for 13 years after its last sighting, in course of which even the camera traps failed to produce concrete evidence of the existence of Formosan clouded leopard, the team of zoologists from Taiwan and the United States declared it extinct.
Guam Flycatcher
The Guam Flycatcher (Myiagra freycineti) was a flycatcher species endemic to the island of Guam, wherein it was referred to as chuguangguang. The bird was found in abundance in this region until early 1970s, but the introduction of the brown tree snake changed the equations for the species. The predation by brown tree snakes reduced the population of the Guam Flycatcher and eventually resulted in its extinction. The flycatcher was last seen in this region in 1983.
Alaotra Grebe
The Alaotra Grebe (Tachybaptus rufolavatus) was a small waterbird endemic to Lake Alaotra--the largest lake in Madagascar--and other lakes in the vicinity. Also known as the Delacour's Little Grebe or Rusty Grebe, it was primarily a sedentary bird which was not capable of flying over long distances because of its small wings. With nowhere to go, the species was affected by habitat destruction which resulted in a significant decline in their numbers.
The population further reduced as several birds either died after getting entangled into monofilament gillnets, or were predated upon by the newly introduced snakehead murrels. The Alaotra Grebe was last seen in September 1985 and 25 years later, in 2010, it was finally declared extinct.
Hawaiian Thrush
The Hawaiian Thrush (Myadestes obscurus)--called the ʻŌmaʻo in its native habitat--was a small bird native to the Hawaiian island of Kaua'i in the United States. Now that it has become extinct, it might seem unbelievable, but it was the most common forest bird in this region until the end of the 19th century. It was one of the many species that were affected by the introduction of alien species in Hawaii. The last reliable sighting of Hawaiian Thrush was recorded in 1985.
The competition from alien species, diseases carried by some of these aliens, and habitat destruction by feral pigs, took a toll on the Hawaiian Thrush population.
It was found in abundance at all elevations at one point of time, but the invasion of its natural habitat by the alien species resulted in its habitat being restricted to the dense montane forests of Hawaii by the 1920s. The population continued to decline, and eventually even the estimated 24 birds left in the wild by 1980s, succumbed to the circumstances.
Aldabra Brush Warbler
The Aldabra Brush Warbler (Nesillas aldabrana) was a small bird endemic to the atoll of Aldabra in the Seychelles. The species was seen for the first time in 1967, after which it virtually disappeared and was only seen again in 1975. It had a limited range, which was already a problem, and the habitat destruction caused by goats and tortoises just made things worse for it.
At the same time, the introduction of rats and cats in its native habitat also played an important role in driving the species to extinction. Their population continued to decline over the course of time and by 1983, only a male Aldabra Brush Warbler was left. When this lone male died in 1986, it marked the end of the Aldabra Brush Warbler and it was officially listed as extinct in 1994.
Craugastor escoces
Amphibians are considered most vulnerable to climate change, and the number of frog species that have either become extinct, or are on the verge of extinction, makes it a lot more obvious. One such species which succumbed to climate change was the Craugastor escoces endemic to Costa Rica. The last recorded sighting of the Craugastor escoces came in 1986.
It inhabited the rivers and streams of the subtropical or tropical moist montane forests on the volcanic slopes in this region. Other than climate change, the species was also affected by Chytridiomycosis, an infectious disease of amphibians. After the follow-up surveys failed to find the species in the wild, it was enlisted as an extinct species by the IUCN in 2006.
Dusky Seaside Sparrow
The Dusky Seaside Sparrow (Ammodramus maritimus nigrescens) was a subspecies of the Seaside Sparrow, found in Florida. A non-migratory species, it inhabited the natural salt marshes of Merritt Island and St. Johns River. The extinction of this species began with the introduction of DDT in its food chain, when the administration sprayed the pesticide over the marshes in a bid to control mosquito growth.
Soon after this incident, the population of this species plummeted from 2000 breeding pairs to 600. Habitat destruction for the species continued with the flooding of Merritt Island, which was the nesting ground for the species, and subsequent draining of the marshes to make way for a highway. The last sighting of the Dusky Seaside Sparrow came in 1979, while the last known individual in captivity died in 1987. The seaside sparrow subspecies was officially declared extinct in December 1990.
Kaua'i 'O'o
The Kaua'i 'O'o (Moho braccatus), native to the Kauaʻi island in Hawaii, was one of the smallest among the Hawaiian honeyeaters. This species was abundantly found in the subtropical forests of the Kaua'i Island until the beginning of the 20th century. The introduction of the black rats, domestic pigs and mosquitoes, which were the carriers of certain avian diseases, dealt the first blow to the Kaua'i 'O'o population in the wild.
The few captured and kept in captivity were unable to cope with the captive conditions, and died. The Kaua'i 'O'o was last heard of in 1987. When none of the efforts to find the species in the wild yielded results, it was finally declared extinct.
Atitlan Grebe104
The Atitlan Grebe (Podilymbus gigas), also known as the Giant Grebe or the Poc, was a water bird endemic to the Lago de Atitlan (Lake Atitlan) in Guatemala. The Atitlan Grebe suffered due to the introduction of smallmouth and largemouth bass in this lake in 1950s and 1960s, which resulted in the depletion of food sources for it.
The population of this water bird decreased to 200 in 1960 and further plummeted to less than 80 by 1965. Though there was a slight recovery in the Atitlan Grebe population in 1970s, the earthquake that hit Guatemala in 1976 fractured the lake bed and drained the water, thus resulting in loss of habitat for the species. The bird was never able to recover from this blow. It was last seen in 1989, and was finally declared extinct by the IUCN in 2008 after repeated searches failed to yield any result.
Golden Toad
The golden toad (Bufo periglenes), also referred to as the Monteverde toad or Orange toad, was a true toad, endemic to the cloud-covered tropical forests of Costa Rica. The beautiful amphibian disappeared from the Earth's ecosystem in 1989.
The extinction of the Golden toad is believed to be a part of the large-scale decline of amphibian population owing to sudden climate change. Among the other factors cited for the sudden extinction of this toad, the prominent ones were fungal epidemic, which swiped out the amphibian population, and unusually warm dry climate, which led to the early evaporation of pools even before the tadpoles matured. The last confirmed sighting of the Golden toad was recorded on 15th May, 1989, and the species was declared extinct after the subsequent efforts to find it failed to yield any results.
Pyrenean Ibex
The Pyrenean ibex (Capra pyrenaica pyrenaica) was a subspecies of the Spanish ibex, that inhabited the Pyrenees mountain range between France and Spain. Extensive poaching and the inability of the species to compete with the other animals in its native habitat took its toll on the population of this species.
By 1900, their population in the wild was reduced to less than 100 individuals. Conservation measures were implemented as the population continued to decline over the next few years, with less than 40 individuals left by 1910. These measures did help the species survive for a few more decades, but the population remained negligible throughout. The species eventually became extinct on January 6, 2000, with the death of last Pyrenean ibex, which got crushed beneath a falling tree. An attempt to clone the Pyrenean ibex seemed successful in January 2009, but the newborn clone died within a few minutes of its birth due to lung failure, and the animal became extinct again.
Western Black Rhinoceros
The western black rhinoceros (Diceros bicornis longipes), also known as the West African black rhinoceros, was a black rhino subspecies native to the Savanna of central-west Africa. Like other rhino species, even the Western black was hunted extensively for its horn which was in huge demand in the international market. The species was severely affected by heavy poaching towards the end of the 19th and beginning of the 20th century.
After a slight revival in the 1930s, the population of this species only witnessed a downward trend. Somewhere around hundred individuals were left in the wild by 1980s and only around 10 by 2000. The failure to curb poaching eventually resulted in the extinction of the Western black rhino somewhere between 2000-2006. After all the efforts to find it in the wild failed, the species was finally added to the IUCN Red List in 2011.
Other than these, there exist some animals which have not been sighted since a long time. These species are categorized as 'likely extinct', like the Zanzibar Leopard (Panthera pardus adersi), functionally extinct, like the baiji (Lipotes vexillifer), or extinct in the wild (EW), like the Seychelles giant tortoise (Aldabrachelys hololissa). There also exist species which were considered extinct at one point of time, but were later discovered in the wild; Holdridge's toad and Vegas Valley leopard frog
are the best examples of the same. While rediscovery of a species is no doubt something to rejoice about, one also needs to understand that these species are not 'out of danger' as yet.

The exact cause of the extinction of dinosaurs may not have been ascertained as yet, but the cause of extinction of most--if not all--of the animals in the aforementioned list is no doubt traced to human activities, either directly or indirectly. These causes range from loss of habitat as a result of human activities to excessive hunting and poaching for food or their horns, skin, etc.
Extinction of Animals Causes
A look at the various factors which can contribute to the extinction of animals. Though there are several causes of extinction, prominent ones among these are loss of habitat, global warming, and hunting--the details of each of these are discussed below.
Deforestation
A non-linear relationship exists between the land area and the number of species residing in that area, i.e., smaller the area, less number of species it will support and vice versa. Deforestation has shrunk the green zones of the planet, which, in turn, has resulted in loss of habitat of several species of plants and animals. As a result, animals now have to venture out of their set zones in search of food, which, in turn, makes them vulnerable to a life-threatening conflict with mankind.
Global Warming
Scientific estimates suggest that around 70 species of frogs have been wiped off the planet as a result of climate change. And this is just the tip of the iceberg considering that several species of animals, including the penguins and polar bears, have become vulnerable to extinction as a result of this increase in global temperature. Several species of animals will bear the brunt of global warming unless we take the necessary precautions to save them.
Hunting
Dodo is a textbook example of extinction as a result of hunting. Extensive hunting of this flightless bird led to its extinction by mid 17th century. It took humans only a few years to wipe this helpless bird off the planet. Various species, including tigers, cheetahs, rhinos, and elephants, have been extensively poached to meet the high demand for their skin, bones, tusks, etc., in the international market and that continues unabated even today.
Other than these three causes, predation by other species (especially a newly introduced species), diseases, increasing competition, genetics, and demographic phenomena have also played a significant role in the extinction of several species. The number of species which have succumbed to human-induced threats, such as loss of habitat and poaching, far exceeds the number of species that have become extinct as a result of predation and genetics.

The grave picture doesn't just end there; the fact that the IUCN list of endangered animals continues to grow with time is also something which we have to be worried about. Last time the IUCN list was evaluated, i.e., in October 2012, 20219 species were threatened with extinction. Not even a year has passed, and the number has reached 20934 species; the list continues to grow. (Note: The number provided doesn't just include animals, but also includes plants, which are equally important for the planet's ecosystem).

The extinction of a particular species puts tremendous pressure on the fellow species as well as the ecosystem. It is but obvious that the tigers will be left with no option, but to encroach upon human settlements for food if the deer population is exhausted. Similarly, the number of herbivores will rise if the tiger population comes down, which, in turn, will lead to depletion of vegetation cover as a result of overfeeding by these herbivores.

The rate at which we are losing these animals is alarming, and if proper measures are not taken soon we may end up losing a large chunk of the animal kingdom - something which will indirectly affect us. In fact, the adverse effects have already started to show - and the man-animal conflict is a prominent evidence of the same. It's high time we understand that we are a part of the ecosystem, and any alterations in the ecosystem are invariably going to effect us.