Animal extinctions can be caused by natural events such as global warming or cooling or changes in sea levels. In recent times, however, human activity has been responsible.
Habitat destruction as agricultural land expands and forests are cut down is the main cause of modern extinctions, along with pollution, the introduction of exotic species, and overfishing or hunting.
Extinction of an animal species occurs when the last individual member of that species dies. Although a species may be "extinct in nature", the species will not become extinct until each individual, regardless of location, captivity or reproductive capacity, has died.
Most extinct species became extinct as a result of natural causes. But we have already seen that other animals, such as the carrier pigeon, became extinct due to human-induced habitat loss and excessive hunting. Man-made environmental issues are also creating serious challenges for several endangered or endangered species.
The nonprofit Endangered Species International estimates that 99.9 percent of the animals that ever existed on earth have become extinct due to catastrophic events that occurred while the Earth was evolving. When these events cause animals to die, it is called mass extinction. There have been multiple mass extinctions due to natural cataclysmic events. While previous mass extinctions occurred long before recorded history, many scientists believe we are immersed in one: the sixth mass extinction of flora and fauna.
There have been no mass extinctions in the last 500 million years, but now that human activities are affecting the Earth, extinctions are occurring at an alarming rate. A normal extinction rate, due to natural causes, is 1 to 5 species per year. However, with human activities such as burning fossil fuels and destroying habitats, we are losing plant, animal and insect species at an alarmingly rapid rate.
Scientists at the Center for Biological Diversity estimate that the rate is a thousand more, or even ten thousand, than 1 to 5. They believe that dozens of animals are becoming extinct every day. The largest species that are rapidly heading towards extinction are amphibians. When frogs and other amphibians begin to die in large numbers, other species fall into domino effect. Save the Frogs, an organisation dedicated to understanding the threat to frogs and other amphibians, estimates that one-third of species are already on the verge of extinction.
It's probably the most famous extinct species. The dodo (Raphus cucullatus), endemic to Mauritius, was sentenced within a few decades.
The first recorded mention of the nonflying bird was made by Dutch sailors in 1598; the last sighting of a Dodo bird was in 1662. Despite its abundance during the 17th century, very little remains in museums as evidence of its existence.
There are some partial skeletons: a skull in Copenhagen, a beak in Prague, a leg in the Natural History Museum and a head and leg in Oxford. The only known complete bird was in the collection of John Tradescant who bequeathed it to the Ashmolean Museum in Oxford; unfortunately it rotted and ended up being burned.
Thanks to the dedication of a curator at the Ashmolean Museum, the head and a leg were saved and are now in the Oxford University Museum of Natural History
The gastric incubator frog (Rheobatrachus silus) was an Australian amphibian species with a quite particular reproductive system.
Originally from Queensland, Australia, the female swallowed the fertilized eggs and incubated them in her own stomach, which grew gradually until almost 40 percent of the weight corresponded to the offspring. After six weeks, the offspring came out through the mother's mouth fully developed. It has been considered extinct since 2002.
Image Credit:The Rainforest Information Centre
The Formosa nebulous leopard (Neofelis nebulosa brachyura), also known as the Taiwan panther nebula, was a subspecies endemic to this island formerly called Formosa.
The truth is that although since 1910 there was no scientific confirmation of its existence, scientists had resisted declaring this species extinct, concluding that the lack of observations was due to its scarcity and elusive character.
Poaching, the destruction of its habitat for agriculture and the expansion of human communities contributed to the complete disappearance of this great predator.
The migratory pigeon (Ectopistes migratorius) was one of the most spectacular birds in the world. It could reach speeds of almost 100 kilometers per hour.
At the height of their population, they numbered up to five billion, making them the most populated bird species on the planet (their flocks were impressive). Unfortunately, with the arrival of the Europeans, tens of millions were sacrificed each year.
They were hunted on an industrial scale for cheap meat, until the last migratory wild pigeon was seen in 1901. The Cincinnati Zoo was home to the last captive bird, Martha, who died on September 1, 1914.
It was the rarest subspecies of black rhino. This subspecies once roamed sub-Saharan Africa, but was a victim of poaching.
Its population was in the hundreds in 1980, and fell to 10 in 2000. Just five years later, no one could be observed. Finally, the IUCN (International Union for Conservation of Nature) declared it extinct in September 2011.
It was between 3-3.8 meters long and 1.4-1.7 meters high. It weighed between 800-1,300 kg. and had two horns. Precisely the belief that its horns had medicinal properties led to exacerbated poaching.
A genus of extinct Hawaiian birds, including four species: Moho apicalis, Moho bishopi, Moho nobilis and Moho braccatus.
The mold became extinct due to hunting and habitat loss. The last bird of this type was seen in Hawaii in 1934.
The bucardo or ibex pirenaico (Capra pyrenaica pyrenaica) was a subspecies of the Spanish ibex.
It wandered frequently in the Pyrenees, but its population fell sharply in the 19th and 20th centuries. The reasons for its decline are still unknown. It was declared extinct in 2000.
Two of the four subspecies of the Spanish ibex still exist: the western Spanish ibex, found in the Picos de Europa, and the southeastern Spanish ibex, common in the Sierra Nevada.
The baiji (Lipotes vexillifer), also called Chinese river dolphin, could only be found in the Yangtze River in China. These mammals could grow up to 2.5 meters long. They relied on echolocation to navigate and search for food because of their small eyes and poor eyesight. Their numbers dropped dramatically from the 1950s onwards.
As China industrialised, the river was used for fishing, transport and hydropower, which had a great effect on mammals. It was declared extinct in 2006.
Macrotis, commonly known as bilbies, has two species. The species Macrotis leucora - very similar to a rabbit - became extinct in the 1950s.
It was a small omnivorous animal from Australia (barely 400 grams in weight) that ended up becoming extinct 50 years after its discovery, mainly due to predators such as foxes and cats. The other surviving species, Macrotis lagotis, is in a vulnerable state according to IUCN.
The quagga (Equus quagga quagga) was a subspecies of the common zebra. It was quite curious, as it only had stripes on the front half of its body. It lived in South Africa and was very persecuted after Dutch settlers arrived and found it competing with domestic animals for fodder.
It became extinct in the wild in 1878 and the last captive specimen died in Amsterdam in 1883. It is the only extinct animal whose DNA has been fully extracted, sequenced and studied.
The tilacino (Thylacinus cynocephalus) or Tasmanian tiger was a marsupial that inhabited Australia, New Guinea and Tasmania.
Its population became extinct in the 1960s for reasons still unknown. It was a large carnivorous marsupial unrelated to tigers. It looked like a medium-sized to large dog (it weighed 30 kg with a length from nose to tail of almost 2 meters), but the dark stripes gave a certain air to the tiger.
It is believed that he was pursued to extinction, encouraged by the rewards; human invasion of his habitat and disease could also have contributed. Tasmania's last wild tiger was killed between 1910 and 1920, and the last captive died at Hobart Zoo, Tasmania in 1936.
Smilodon was one of the most popular prehistoric mammals due to its enormous canines. An adult could weigh between 55 and 300 kilograms.
Incorrectly called saber-toothed tiger (because it is a different species from the current tiger), it lived in North America during the Pleistocene period, but its entire population died 10,000 years ago, towards the end of the last Ice Age, coinciding with the arrival of humans to continents to which they had never had access before.
It is believed that the Eurasian uro (bos primigenius primigenius) appeared approximately two million years ago, with Bos acutifrons as the first exponent of this genus.
We can consider it the ancestor of domestic cattle. These animals lived in different parts of North Africa, Asia and even Europe, where it used to be one of the largest herbivores. It has been considered extinct since 1627 due to hunting, forest retreat and domestication.
The woolly mammoth or tundra mammoth (Mammuthus primigenius) reached a height of more than three meters and weighed up to six tons. It coexisted with the first humans, who used its bones and tusks to make tools and housing and also hunted it for food with its meat.
Small populations survived on the island of São Paulo, off the coast of Alaska, and on the island of Wrangel, in the Arctic Ocean. It became extinct in 1700 BC. Whole frozen bodies of this mammoth species have been found in areas such as Siberia.
The Labrador duck (Camptorhynchus labradorius) was discovered in 1789, and only 89 years later it became extinct. The reason for its disappearance is unknown, but it was probably indiscriminate hunting.
This multicolored North American duck migrated annually from New Jersey to New England. There are no records since the last specimen was collected in 1875.
The giant alca (Pinguinus impennis) was also a large, non flying bird located in the North Atlantic and even as far south as northern Spain. It had an average height of 75-85 cm and weighed about five kg.
He was a powerful swimmer, which made him a fantastic underwater hunter. But on land they were very clumsy. The first explorers hunted them as an easily available food source. By 1835 they had all been exterminated.
London's Natural History Museum houses a copy with the following legend: “It is one of the most powerful symbols of the damage that humans can cause. The species became extinct in the 19th century as a result of centuries of intense human exploitation.”
The giant Pinta turtle (Chelonoidis abingdoni) was a subspecies endemic to the Pinta island of the Galapagos Islands (Ecuador).
It is considered extinct, and the last known specimen, Lonesome George, died in 2012 from natural causes (probably at age 112).
The moas (Dinornithidae) were non flying birds that inhabited New Zealand. Their species vary in size, ranging from the size of a rooster to giant moas that could reach 3 meters in height and weigh about 250 kg. It was one of the largest birds ever to exist. It became extinct in 1400 due to excessive hunting by Maori.
Like the dodo, it's a non flying bird. And it's not surprising because of its size. The elephant bird (Aepyornithidae), was huge, could weigh over 550 kilograms and be up to three meters high and 2.3 meters long. It lived on the island of Madagascar. Between the seventeenth and eighteenth centuries, it became extinct for reasons still unknown. However, it is believed that abusive human hunting played a key role, as in so many other species.
The dark coastal sparrow (Ammodramus maritimus nigrescens) was a non-migratory species of marine sparrow that used to live in South Florida, in the natural salt marshes of Merrit Island and along the St. Johns River. In 1990, this bird was officially declared extinct after humans sprayed DDT insecticide on its habitat. The last known individual died on June 17, 1987.
Steller's sea cow (Hydrodamalis gigas) was one of those large mammals like whales. It existed at the time of the Holocene and reached up to nine meters in length (and weighed 4 to 10 tons).
Unfortunately, it was hunted to extinction in 1768. The German naturalist Georg Wilhelm Steller described its skin as "more like the bark of an ancient oak than the skin of an animal, almost impenetrable to an axe or the tip of a hook. A complete skeleton can be seen at the Helsinki Natural History Museum in Finland.
The Cuban macaw (Ara tricolor), a relative of the parrots, inhabited the islands of Cuba and Youth. This species measured between 45 and 50 centimeters and had a reddish and orange forehead and a yellow neck. During the flight, in which it opened its tail, it looked magnificent, majestic thanks to its striking coloration and its considerable size. This macaw was the last Caribbean macaw species to become extinct before 1900. Responsible? Deforestation and mass hunting.
The Carolina parrot (Conuropsis carolinensis) was the only species of the genus Conuropsis that existed and also the only species of parrot native to North America east of Mississippi. It was a small green parrot with a bright red head. Very spectacular. Unfortunately, deforestation, mass hunting, invasive species and disease caused its extinction. The last specimen in captivity died in 1918.
The Cape blue antelope (Hippotragus leucophaeus) disappeared not only because its habitat was invaded by agriculture, but also because European settlers hunted them indiscriminately in the African savannah. It was an animal that despite being the smallest species of its genus, had to be a very beautiful animal.t had a body weight of about 150 kg and a length of 1.1 meters in adulthood. The blue antelope was declared extinct in 1800.
The huia (Heteralocha acutirostri) was a species of bird endemic to the North Island of New Zealand. It was a spectacular bird, with a body length of 45 cm. This large hummingbird species became extinct in the 20th century due to rampant skin hunting and massive deforestation by European settlers. It was not much studied before its extinction, so many details about this species are unknown.