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108-956: In 1989, out of concern over rhino poaching , residents from Serowe established a wildlife reserve with the support of Ian Khama . The first four white rhinos were introduced in 1992 and the sanctuary was officially granted the land around the Serwe Pan, a dry lake , by the Ngwato Land Board in 1993. The Critically Endangered black rhino was reintroduced in 2002. The Sanctuary is home to other wildlife which have settled naturally or been translocated in. This includes giraffes , elands , red hartebeests , gemsboks , zebras , blue wildebeests , springboks , impalas , waterbucks , kudus , cheetahs , black-backed jackals , brown hyenas , leopards , ostriches , antelopes , bat-eared foxes , lynxes , African wild cats , steenboks , duikers , caracals , and small spotted genets . Bird species identified at

216-438: A food chain who lose their prey. "Species coextinction is a manifestation of one of the interconnectednesses of organisms in complex ecosystems ... While coextinction may not be the most important cause of species extinctions, it is certainly an insidious one." Coextinction is especially common when a keystone species goes extinct. Models suggest that coextinction is the most common form of biodiversity loss . There may be

324-657: A nautilus to the Royal Society that was more than two feet in diameter, and morphologically distinct from any known living species. Hooke theorized that this was simply because the species lived in the deep ocean and no one had discovered them yet. While he contended that it was possible a species could be "lost", he thought this highly unlikely. Similarly, in 1695, Sir Thomas Molyneux published an account of enormous antlers found in Ireland that did not belong to any extant taxa in that area. Molyneux reasoned that they came from

432-415: A species or a population is the variety of genetic information in its living members. A large gene pool (extensive genetic diversity ) is associated with robust populations that can survive bouts of intense selection . Meanwhile, low genetic diversity (see inbreeding and population bottlenecks ) reduces the range of adaptions possible. Replacing native with alien genes narrows genetic diversity within

540-436: A viable population for species preservation and possible future reintroduction to the wild, through use of carefully planned breeding programs . The extinction of one species' wild population can have knock-on effects, causing further extinctions. These are also called "chains of extinction". This is especially common with extinction of keystone species . A 2018 study indicated that the sixth mass extinction started in

648-639: A German entrepreneur and a local private security expert with the goal to prevent Rhinoceros deaths. Rhisotope is an initiative by University of Witwatersrand in cooperation with Rosatom where small amounts of rare radioisotopes are injected into the rhino horns. The nuclides have no health impact on rhinos or humans, but can be easily detected on borders thus increasing risk for the traders. The Environmental Investigation Agency reported that up to and including September 2018, 583 seizures of rhino horn had been recorded consisting of approximately 1,770 horns and roughly weighing 4,927 kilograms. The countries with

756-474: A Lazarus species when extant individuals were described in 2019. Attenborough's long-beaked echidna ( Zaglossus attenboroughi ) is an example of a Lazarus species from Papua New Guinea that had last been sighted in 1962 and believed to be possibly extinct, until it was recorded again in November 2023. Some species currently thought to be extinct have had continued speculation that they may still exist, and in

864-495: A cascade of coextinction across the trophic levels . Such effects are most severe in mutualistic and parasitic relationships. An example of coextinction is the Haast's eagle and the moa : the Haast's eagle was a predator that became extinct because its food source became extinct. The moa were several species of flightless birds that were a food source for the Haast's eagle. Extinction as

972-429: A common ancestor with modern horses. Pseudoextinction is much easier to demonstrate for larger taxonomic groups. A Lazarus taxon or Lazarus species refers to instances where a species or taxon was thought to be extinct, but was later rediscovered. It can also refer to instances where large gaps in the fossil record of a taxon result in fossils reappearing much later, although the taxon may have ultimately become extinct at

1080-432: A detector dog. The horns were hidden in household objects stored in eight boxes heading for Dubai. In 1977, the international trade of rhino horn was declared illegal by CITES. Although international trade is illegal, domestic trade regulations are determined by the nominated national government agencies in each country. The South African DEA is responsible for protecting and conserving South Africa’s environment. In 2009,

1188-399: A fact that was accepted by most scientists. The primary debate focused on whether this turnover caused by extinction was gradual or abrupt in nature. Cuvier understood extinction to be the result of cataclysmic events that wipe out huge numbers of species, as opposed to the gradual decline of a species over time. His catastrophic view of the nature of extinction garnered him many opponents in

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1296-708: A higher risk of extinction and die out faster than less sexually dimorphic species, the least sexually dimorphic species surviving for millions of years while the most sexually dimorphic species die out within mere thousands of years. Earlier studies based on counting the number of currently living species in modern taxa have shown a higher number of species in more sexually dimorphic taxa which have been interpreted as higher survival in taxa with more sexual selection, but such studies of modern species only measure indirect effects of extinction and are subject to error sources such as dying and doomed taxa speciating more due to splitting of habitat ranges into more small isolated groups during

1404-405: A large range, a lack of individuals of both sexes (in sexually reproducing species), or other reasons. Pinpointing the extinction (or pseudoextinction ) of a species requires a clear definition of that species . If it is to be declared extinct, the species in question must be uniquely distinguishable from any ancestor or daughter species, and from any other closely related species. Extinction of

1512-592: A later point. The coelacanth , a fish related to lungfish and tetrapods , is an example of a Lazarus taxon that was known only from the fossil record and was considered to have been extinct since the end of the Cretaceous Period . In 1938, however, a living specimen was found off the Chalumna River (now Tyolomnqa) on the east coast of South Africa. Calliostoma bullatum , a species of deepwater sea snail originally described from fossils in 1844 proved to be

1620-587: A mathematical model that falls in all positions. By contrast, conservation biology uses the extinction vortex model to classify extinctions by cause. When concerns about human extinction have been raised, for example in Sir Martin Rees ' 2003 book Our Final Hour , those concerns lie with the effects of climate change or technological disaster. Human-driven extinction started as humans migrated out of Africa more than 60,000 years ago. Currently, environmental groups and some governments are concerned with

1728-456: A natural part of the evolutionary process. Only recently have extinctions been recorded and scientists have become alarmed at the current high rate of extinctions . Most species that become extinct are never scientifically documented. Some scientists estimate that up to half of presently existing plant and animal species may become extinct by 2100. A 2018 report indicated that the phylogenetic diversity of 300 mammalian species erased during

1836-441: A new mega-predator or by transporting animals and plants from one part of the world to another. Such introductions have been occurring for thousands of years, sometimes intentionally (e.g. livestock released by sailors on islands as a future source of food) and sometimes accidentally (e.g. rats escaping from boats). In most cases, the introductions are unsuccessful, but when an invasive alien species does become established,

1944-610: A population a higher chance in the short term of surviving an adverse change in conditions. Effects that cause or reward a loss in genetic diversity can increase the chances of extinction of a species. Population bottlenecks can dramatically reduce genetic diversity by severely limiting the number of reproducing individuals and make inbreeding more frequent. Extinction sometimes results for species evolved to specific ecologies that are subjected to genetic pollution —i.e., uncontrolled hybridization , introgression and genetic swamping that lead to homogenization or out-competition from

2052-407: A race of animals to become extinct. A series of fossils were discovered in the late 17th century that appeared unlike any living species. As a result, the scientific community embarked on a voyage of creative rationalization, seeking to understand what had happened to these species within a framework that did not account for total extinction. In October 1686, Robert Hooke presented an impression of

2160-1058: A record high of 1,215 in 2014. At this point it was decided to translocate more than a hundred (exact numbers unknown) tagged and micro-chipped rhinos to Botswana's remote wilderness, where at the time, they were safer. Some were relocated to the Khama Rhino Sanctuary and some to the Okavango on private concessions, where they received protection from rangers and the BDF. The total number of rhino deaths have since fallen. In 2018, 769 rhinos were poached in South Africa, and in 2019, 594. Sentences of 24 to 25 years in prison have been handed out to convicted poachers in 2019 and 2020. Mitigating measures implemented by 2020 include improved situational awareness and reaction times, deployment of technology and improved information collection and sharing among law enforcement departments. National en regional cooperation

2268-502: A reduction in agricultural productivity. Furthermore, increased erosion contributes to poorer water quality by elevating the levels of sediment and pollutants in rivers and streams. Habitat degradation through toxicity can kill off a species very rapidly, by killing all living members through contamination or sterilizing them. It can also occur over longer periods at lower toxicity levels by affecting life span, reproductive capacity, or competitiveness. Habitat degradation can also take

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2376-486: A result of climate change has been confirmed by fossil studies. Particularly, the extinction of amphibians during the Carboniferous Rainforest Collapse , 305 million years ago. A 2003 review across 14 biodiversity research centers predicted that, because of climate change, 15–37% of land species would be "committed to extinction" by 2050. The ecologically rich areas that would potentially suffer

2484-479: A species (or replacement by a daughter species) plays a key role in the punctuated equilibrium hypothesis of Stephen Jay Gould and Niles Eldredge . In ecology , extinction is sometimes used informally to refer to local extinction , in which a species ceases to exist in the chosen area of study, despite still existing elsewhere. Local extinctions may be made good by the reintroduction of individuals of that species taken from other locations; wolf reintroduction

2592-439: A species may come suddenly when an otherwise healthy species is wiped out completely, as when toxic pollution renders its entire habitat unliveable; or may occur gradually over thousands or millions of years, such as when a species gradually loses out in competition for food to better adapted competitors. Extinction may occur a long time after the events that set it in motion, a phenomenon known as extinction debt . Assessing

2700-404: A species or group of species. "Just as each species is unique", write Beverly and Stephen C. Stearns , "so is each extinction ... the causes for each are varied—some subtle and complex, others obvious and simple". Most simply, any species that cannot survive and reproduce in its environment and cannot move to a new environment where it can do so, dies out and becomes extinct. Extinction of

2808-518: A subsequent report, IPBES listed unsustainable fishing, hunting and logging as being some of the primary drivers of the global extinction crisis. In June 2019, one million species of plants and animals were at risk of extinction. At least 571 plant species have been lost since 1750, but likely many more. The main cause of the extinctions is the destruction of natural habitats by human activities, such as cutting down forests and converting land into fields for farming. A dagger symbol (†) placed next to

2916-616: A symbol of wealth. Rhino horn is used as an ingredient in certain Traditional Chinese Medicine practices. The surge in poaching during the 1970s and 1980s was caused by the increased demand coming from South-East Asian countries. Rhino horn was removed from the official list of Traditional Chinese Medicine in the Chinese Medicine Pharmacopeia in 1993, as there are no measurable health benefits and no scientific evidence supporting its use. In 2018, China reversed

3024-517: A temporary ban was made on the trade of rhino horn domestically in South Africa, which was later lifted in April 2017 after an ongoing legal dispute between the DEA and private rhino farmers. The decision to lift the ban was motivated by the belief that by legalising the domestic trade of rhino horns criminal activity would be reduced and consumption of rhino horn could be regulated sustainably and ethically. Besides,

3132-434: Is a commodity valued at 3 times that of gold. Statistics suggest that the future of the rhino population is uncertain, consequently increasing the value of the rhino horn as a commodity. As a result, in recent times rhino horns are being stockpiled by investors that believe they will appreciate due to their scarcity. Poachers are often hired by the sellers and traffickers of rhino horns. A variety of methods have been used by

3240-517: Is also evidence to suggest that this event was preceded by another mass extinction, known as Olson's Extinction . The Cretaceous–Paleogene extinction event (K–Pg) occurred 66 million years ago, at the end of the Cretaceous period; it is best known for having wiped out non-avian dinosaurs , among many other species. According to a 1998 survey of 400 biologists conducted by New York 's American Museum of Natural History , nearly 70% believed that

3348-444: Is an example of this. Species that are not globally extinct are termed extant . Those species that are extant, yet are threatened with extinction, are referred to as threatened or endangered species . Currently, an important aspect of extinction is human attempts to preserve critically endangered species. These are reflected by the creation of the conservation status "extinct in the wild" (EW) . Species listed under this status by

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3456-585: Is difficult to demonstrate unless one has a strong chain of evidence linking a living species to members of a pre-existing species. For example, it is sometimes claimed that the extinct Hyracotherium , which was an early horse that shares a common ancestor with the modern horse , is pseudoextinct, rather than extinct, because there are several extant species of Equus , including zebra and donkey ; however, as fossil species typically leave no genetic material behind, one cannot say whether Hyracotherium evolved into more modern horse species or merely evolved from

3564-417: Is estimated as 100 to 1,000 times "background" rates (the average extinction rates in the evolutionary time scale of planet Earth), faster than at any other time in human history, while future rates are likely 10,000 times higher. However, some groups are going extinct much faster. Biologists Paul R. Ehrlich and Stuart Pimm , among others, contend that human population growth and overconsumption are

3672-417: Is estimated that there are currently around 8.7 million species of eukaryotes globally, and possibly many times more if microorganisms , such as bacteria , are included. Notable extinct animal species include non-avian dinosaurs , saber-toothed cats , dodos , mammoths , ground sloths , thylacines , trilobites , golden toads , and passenger pigeons . Through evolution , species arise through

3780-408: Is estimated to be around 5,000 and 18,000 respectively. 90% of the remaining black and white rhinos are in the southern African countries of Namibia , Botswana and South Africa . South African Environment Minister Barbara Creecy reported on 1 February 2021 that rhinoceros poaching in that country was down for the sixth year in a row, to 394 animals killed in 2020 for their horns. She attributed

3888-592: Is the destruction of ocean floors by bottom trawling . Diminished resources or introduction of new competitor species also often accompany habitat degradation. Global warming has allowed some species to expand their range, bringing competition to other species that previously occupied that area. Sometimes these new competitors are predators and directly affect prey species, while at other times they may merely outcompete vulnerable species for limited resources. Vital resources including water and food can also be limited during habitat degradation, leading to extinction. In

3996-525: Is the most important determinant of genus extinction at background rates but becomes increasingly irrelevant as mass extinction arises. Limited geographic range is a cause both of small population size and of greater vulnerability to local environmental catastrophes. Extinction rates can be affected not just by population size, but by any factor that affects evolvability , including balancing selection , cryptic genetic variation , phenotypic plasticity , and robustness . A diverse or deep gene pool gives

4104-407: Is the safest method for the poacher as they can maintain a safe distance from the rhino. Another common method of incapacitating rhinos is to tranquilize them. Tranquilizer darts have the advantage of being less noisy than bullets. Since tranquilizer darts require specialized training, rhinos may die from overdose when being tranquilized by poachers. If the rhino survives, it will bleed to death after

4212-472: Is valued at $ 60,000 per kilogram on the black market – more than its weight in gold. In an attempt to prevent the poaching of rhinos, some rhinos in South Africa have been tranquilized and had their horns removed in a process carried out by local national park authorities and private sanctuaries. The Rhino Rescue Project in the South African city of Krugersdorp implemented a technique whereby they infuse

4320-672: The Department of Environmental Affairs (DEA) , the Department of Defence and the South African Police Service . These departments have been actively involved in the arrests of rhino poachers and traffickers in South Africa. Rhino Force has five private anti-poaching squads operating in the Great Kruger area. They patrol the private game reserves that comprise the area, sweeping the borders to detect signs of entry. They originated in South Africa in 2017 through collaboration with

4428-474: The International Union for Conservation of Nature (IUCN) are not known to have any living specimens in the wild and are maintained only in zoos or other artificial environments. Some of these species are functionally extinct, as they are no longer part of their natural habitat and it is unlikely the species will ever be restored to the wild. When possible, modern zoological institutions try to maintain

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4536-477: The Late Pleistocene could take up to 5 to 7 million years to restore mammal diversity to what it was before the human era. Extinction of a parent species where daughter species or subspecies are still extant is called pseudoextinction or phyletic extinction. Effectively, the old taxon vanishes, transformed ( anagenesis ) into a successor, or split into more than one ( cladogenesis ). Pseudoextinction

4644-698: The Okavango Delta , mainly in areas protected by anti-poaching units and armed members of the Botswana Defence Force (BDF). In March 2020 the BDF killed one poacher in the Shaile/Linyanti area, and in April 2020 four others were killed in the Linyanti area. After a sixth poacher was killed, the Botswana government announced that the situation was brought under control. After the rhino poachers have obtained

4752-410: The slender-billed curlew ( Numenius tenuirostris ), not seen since 2007. As long as species have been evolving, species have been going extinct. It is estimated that over 99.9% of all species that ever lived are extinct. The average lifespan of a species is 1–10 million years, although this varies widely between taxa. A variety of causes can contribute directly or indirectly to the extinction of

4860-484: The strata of the Paris basin. They saw alternating saltwater and freshwater deposits, as well as patterns of the appearance and disappearance of fossils throughout the record. From these patterns, Cuvier inferred historic cycles of catastrophic flooding, extinction, and repopulation of the earth with new species. Cuvier's fossil evidence showed that very different life forms existed in the past than those that exist today,

4968-619: The 20 biodiversity goals laid out by the Aichi Biodiversity Targets in 2010, only 6 were "partially achieved" by the deadline of 2020. The report warned that biodiversity will continue to decline if the status quo is not changed, in particular the "currently unsustainable patterns of production and consumption, population growth and technological developments". In a 2021 report published in the journal Frontiers in Conservation Science , some top scientists asserted that even if

5076-451: The Aichi Biodiversity Targets set for 2020 had been achieved, it would not have resulted in a significant mitigation of biodiversity loss. They added that failure of the global community to reach these targets is hardly surprising given that biodiversity loss is "nowhere close to the top of any country's priorities, trailing far behind other concerns such as employment, healthcare, economic growth, or currency stability." For much of history,

5184-605: The Earth is currently in the early stages of a human-caused mass extinction, known as the Holocene extinction . In that survey, the same proportion of respondents agreed with the prediction that up to 20% of all living populations could become extinct within 30 years (by 2028). A 2014 special edition of Science declared there is widespread consensus on the issue of human-driven mass species extinctions. A 2020 study published in PNAS stated that

5292-570: The North American moose and that the animal had once been common on the British Isles . Rather than suggest that this indicated the possibility of species going extinct, he argued that although organisms could become locally extinct, they could never be entirely lost and would continue to exist in some unknown region of the globe. The antlers were later confirmed to be from the extinct deer Megaloceros . Hooke and Molyneux's line of thinking

5400-518: The Paris basin, could be formed by a slow rise and fall of sea levels . The concept of extinction was integral to Charles Darwin 's On the Origin of Species , with less fit lineages disappearing over time. For Darwin, extinction was a constant side effect of competition . Because of the wide reach of On the Origin of Species , it was widely accepted that extinction occurred gradually and evenly (a concept now referred to as background extinction ). It

5508-429: The accumulation of slightly deleterious mutations , then a population will go extinct. Smaller populations have fewer beneficial mutations entering the population each generation, slowing adaptation. It is also easier for slightly deleterious mutations to fix in small populations; the resulting positive feedback loop between small population size and low fitness can cause mutational meltdown . Limited geographic range

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5616-402: The ban on trade on rhino horn. Despite this lack of evidence, many users of Traditional Chinese Medicine still believe rhino horn has medicinal benefits and use it to treat a wide variety of illnesses such as headaches, fevers, convulsions and in some cases cancer. The horn is crushed into a fine powder and manufactured into tablets or dissolved in boiling water and consumed orally. Rhino horn

5724-414: The colonial era in southern Africa, rhinos were hunted recreationally as a sport and for the possession of their horns, which were used as symbol of wealth and prosperity. This led to a gradual but constant decline in rhino populations across southern Africa during the colonial era. In the early 20th century, the white rhino population in South Africa was down to 10, and in 1933 the black rhino population

5832-600: The consequences can be catastrophic. Invasive alien species can affect native species directly by eating them, competing with them, and introducing pathogens or parasites that sicken or kill them; or indirectly by destroying or degrading their habitat. Human populations may themselves act as invasive predators. According to the "overkill hypothesis", the swift extinction of the megafauna in areas such as Australia (40,000 years before present), North and South America (12,000 years before present), Madagascar , Hawaii (AD 300–1000), and New Zealand (AD 1300–1500), resulted from

5940-418: The contemporary extinction crisis "may be the most serious environmental threat to the persistence of civilization, because it is irreversible." Biologist E. O. Wilson estimated in 2002 that if current rates of human destruction of the biosphere continue, one-half of all plant and animal species of life on earth will be extinct in 100 years. More significantly, the current rate of global species extinctions

6048-541: The death of its last member if it loses the capacity to reproduce and recover. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa , where a species presumed extinct abruptly "reappears" (typically in the fossil record ) after a period of apparent absence. More than 99% of all species that ever lived on Earth , amounting to over five billion species, are estimated to have died out. It

6156-481: The decline to both the COVID-19 pandemic and to work by rangers and security personnel and noted that it was still a major problem. During the colonial era, the leading cause of rhino deaths was attributed to uncontrolled hunting. Rhino hunting was considered a recreational activity and the horn was kept by the hunter as a trophy. In more recent times, rhino horns are increasingly being used for decorative purposes and as

6264-471: The deliberate destruction of some species, such as dangerous viruses , and the total destruction of other problematic species has been suggested. Other species were deliberately driven to extinction, or nearly so, due to poaching or because they were "undesirable", or to push for other human agendas. One example was the near extinction of the American bison , which was nearly wiped out by mass hunts sanctioned by

6372-403: The endangered wild water buffalo is most threatened with extinction by genetic pollution from the abundant domestic water buffalo ). Such extinctions are not always apparent from morphological (non-genetic) observations. Some degree of gene flow is a normal evolutionary process; nevertheless, hybridization (with or without introgression) threatens rare species' existence. The gene pool of

6480-575: The event of rediscovery would be considered Lazarus species. Examples include the thylacine , or Tasmanian tiger ( Thylacinus cynocephalus ), the last known example of which died in Hobart Zoo in Tasmania in 1936; the Japanese wolf ( Canis lupus hodophilax ), last sighted over 100 years ago; the American ivory-billed woodpecker ( Campephilus principalis ), with the last universally accepted sighting in 1944; and

6588-443: The extinction crisis. According to the International Union for Conservation of Nature (IUCN), 784 extinctions have been recorded since the year 1500, the arbitrary date selected to define "recent" extinctions, up to the year 2004; with many more likely to have gone unnoticed. Several species have also been listed as extinct since 2004. If adaptation increasing population fitness is slower than environmental degradation plus

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6696-475: The extinction of species caused by humanity, and they try to prevent further extinctions through a variety of conservation programs. Humans can cause extinction of a species through overharvesting , pollution , habitat destruction , introduction of invasive species (such as new predators and food competitors ), overhunting, and other influences. Explosive, unsustainable human population growth and increasing per capita consumption are essential drivers of

6804-533: The field of zoology , and biology in general, and has also become an area of concern outside the scientific community. A number of organizations, such as the Worldwide Fund for Nature , have been created with the goal of preserving species from extinction. Governments have attempted, through enacting laws, to avoid habitat destruction, agricultural over-harvesting, and pollution . While many human-caused extinctions have been accidental, humans have also engaged in

6912-435: The form of a physical destruction of niche habitats. The widespread destruction of tropical rainforests and replacement with open pastureland is widely cited as an example of this; elimination of the dense forest eliminated the infrastructure needed by many species to survive. For example, a fern that depends on dense shade for protection from direct sunlight can no longer survive without forest to shelter it. Another example

7020-448: The funds generated through domestic sales could go towards the preservation and conservation of rhinos in South Africa. Those against the decision argued that it is not a feasible solution to regulate domestic trade as the levels of illegal activity is too high to be controlled effectively. Extinction Extinction is the termination of a taxon by the death of its last member . A taxon may become functionally extinct before

7128-433: The greatest quantity of rhino horns seized are South Africa (1,659 kilograms), China (including Hong Kong) (779 kilograms) and Vietnam (608 kilograms). The biggest rhino horn seizure ever recorded was made in South Africa's North West Province on 13 April 2019. Two men were arrested for the possession of 167 rhino horns after local authorities received a tip-off that a large batch of rhino horns destined for South East Asia

7236-580: The habitat retreat of taxa approaching extinction. Possible causes of the higher extinction risk in species with more sexual selection shown by the comprehensive fossil studies that rule out such error sources include expensive sexually selected ornaments having negative effects on the ability to survive natural selection , as well as sexual selection removing a diversity of genes that under current ecological conditions are neutral for natural selection but some of which may be important for surviving climate change. There have been at least five mass extinctions in

7344-660: The heaviest losses include the Cape Floristic Region and the Caribbean Basin . These areas might see a doubling of present carbon dioxide levels and rising temperatures that could eliminate 56,000 plant and 3,700 animal species. Climate change has also been found to be a factor in habitat loss and desertification . Studies of fossils following species from the time they evolved to their extinction show that species with high sexual dimorphism , especially characteristics in males that are used to compete for mating, are at

7452-447: The history of life on earth, and four in the last 350 million years in which many species have disappeared in a relatively short period of geological time. A massive eruptive event that released large quantities of tephra particles into the atmosphere is considered to be one likely cause of the " Permian–Triassic extinction event " about 250 million years ago, which is estimated to have killed 90% of species then existing. There

7560-426: The horn is removed. Poachers lure the rhino towards a pit they have constructed in attempt to capture and secure the rhino. Trapping rhinos in a pit is often used in conjunction with other poaching techniques such as shooting. In certain areas where high-powered power lines are present, poachers lure the rhino towards the power line, where they use modified equipment to utilise the high-voltage current to electrocute

7668-475: The human era since the Late Pleistocene would require 5 to 7 million years to recover. According to the 2019 Global Assessment Report on Biodiversity and Ecosystem Services by IPBES , the biomass of wild mammals has fallen by 82%, natural ecosystems have lost about half their area and a million species are at risk of extinction—all largely as a result of human actions. Twenty-five percent of plant and animal species are threatened with extinction. In

7776-470: The initiators of rhino preservation and conservation in South Africa and were able to breed white rhinos and bring the species back from extinction in an initiative known as “Operation Rhino”. The population of black rhino recovered to 100,000 by 1960. During the 1970s to the 1980s, poaching of black rhino increased dramatically due to the growing demand for rhino horn in South East Asian countries, where

7884-431: The introduced ( or hybrid ) species. Endemic populations can face such extinctions when new populations are imported or selectively bred by people, or when habitat modification brings previously isolated species into contact. Extinction is likeliest for rare species coming into contact with more abundant ones; interbreeding can swamp the rarer gene pool and create hybrids, depleting the purebred gene pool (for example,

7992-457: The lucrative industry. Since 1977, the international trade of rhino horn has been declared illegal by the Convention on International Trade of Endangered Species (CITES) in response to the concern that increased demand is fuelling the number of rhino deaths due to poaching. The international trade ban of rhino horn has created a lucrative black-market estimated at $ 20 billion a year. Rhino horn

8100-485: The main drivers of the modern extinction crisis. In January 2020, the UN's Convention on Biological Diversity drafted a plan to mitigate the contemporary extinction crisis by establishing a deadline of 2030 to protect 30% of the Earth's land and oceans and reduce pollution by 50%, with the goal of allowing for the restoration of ecosystems by 2050. The 2020 United Nations ' Global Biodiversity Outlook report stated that of

8208-421: The modern understanding of extinction as the end of a species was incompatible with the prevailing worldview. Prior to the 19th century, much of Western society adhered to the belief that the world was created by God and as such was complete and perfect. This concept reached its heyday in the 1700s with the peak popularity of a theological concept called the great chain of being , in which all life on earth, from

8316-490: The name of a species or other taxon normally indicates its status as extinct. Examples of species and subspecies that are extinct include: A species is extinct when the last existing member dies. Extinction therefore becomes a certainty when there are no surviving individuals that can reproduce and create a new generation. A species may become functionally extinct when only a handful of individuals survive, which cannot reproduce due to poor health, age, sparse distribution over

8424-469: The natural course of events, species become extinct for a number of reasons, including but not limited to: extinction of a necessary host, prey or pollinator, interspecific competition , inability to deal with evolving diseases and changing environmental conditions (particularly sudden changes) which can act to introduce novel predators, or to remove prey. Recently in geological time, humans have become an additional cause of extinction of some species, either as

8532-410: The newly emerging school of uniformitarianism . Jean-Baptiste Lamarck , a gradualist and colleague of Cuvier, saw the fossils of different life forms as evidence of the mutable character of species. While Lamarck did not deny the possibility of extinction, he believed that it was exceptional and rare and that most of the change in species over time was due to gradual change. Unlike Cuvier, Lamarck

8640-399: The original population, thereby increasing the chance of extinction. Habitat degradation is currently the main anthropogenic cause of species extinctions. The main cause of habitat degradation worldwide is agriculture, with urban sprawl , logging, mining, and some fishing practices close behind. The degradation of a species' habitat may alter the fitness landscape to such an extent that

8748-509: The poachers to incapacitate rhinos over the years. Once the rhino is incapacitated, the poachers usually cut off the base plate of the rhino's horn with either a machete or a chainsaw in a process called “de-horning”. The most common methods of rhino poaching are: The most common method of killing rhinos is shooting them with a rifle or shotgun. Trained gunmen are hired to carry out the poaching missions utilising advanced combat technologies such as silenced weapons and night vision scopes. Shooting

8856-702: The process of speciation —where new varieties of organisms arise and thrive when they are able to find and exploit an ecological niche —and species become extinct when they are no longer able to survive in changing conditions or against superior competition . The relationship between animals and their ecological niches has been firmly established. A typical species becomes extinct within 10 million years of its first appearance, although some species, called living fossils , survive with little to no morphological change for hundreds of millions of years. Mass extinctions are relatively rare events; however, isolated extinctions of species and clades are quite common, and are

8964-615: The rangers are armed with anti-personal firearms the quality of which depends on country restrictions and funding. For example, Zimbabwe Park rangers are permitted to carry AK-47 , however, in South Africa much of the wildlife is privately owned and hence the Private Security companies that protect the wildlife are not permitted to carry fully automatic weapons. Rhino sanctuaries are private and secure locations that aim to breed rhinos to restore their population. At certain sanctuaries,

9072-410: The relative importance of genetic factors compared to environmental ones as the causes of extinction has been compared to the debate on nature and nurture . The question of whether more extinctions in the fossil record have been caused by evolution or by competition or by predation or by disease or by catastrophe is a subject of discussion; Mark Newman, the author of Modeling Extinction , argues for

9180-470: The rhino horn is deemed to be an important ingredient in Traditional Chinese Medicine . Between 1970 and 1992, 96% of the black rhino population was eliminated, with the predominant cause of rhino death due to poaching. By 2010, there were over 20,000 white rhinos in South Africa, which made up 90% of the rhino population in Africa. The rhino population continued to grow despite the presence of poachers, which

9288-488: The rhino horn with a pink dye that is toxic to humans. This procedure takes place while the rhino is sedated and causes no harm to the rhino or other animals in the national parks. Since the dye is toxic to humans, the horn is no longer of use in Traditional Chinese Medicine and as a result diminishes in trade value. Armed national park rangers in South Africa have established anti-poaching units to combat

9396-534: The rhino horns are trimmed and stockpiled to reduce poaching and accumulate value. The world’s biggest rhino farm consists of over 1,300 rhinos and is situated in Krugersdorp, South Africa. There exist both governmental and independent organisations that attempt to combat rhino-poaching in South Africa. The South African government has integrated several of their organisations to collectively suppress rhino poaching in South Africa. The governmental departments include

9504-534: The rhino horns, they sell the horns to traffickers. Traffickers act as the intermediaries between the poachers and the end users, with most of the demand coming from consumer markets in the South East Asian nations of China and Vietnam. In recent years, the demand for rhino horn has increased due to the growing purchasing power of the Asian middle class as well as the rising scarcity of rhino horn. The trafficking enterprises are sophisticated global organisations supported by

9612-562: The rhino poachers on the front line, sometimes resulting in death of the poachers. Private security organisations act independently and in collaboration with national park rangers. Both parties, private and public, employ tactics and technology generally reserved for the battlefield. These organizations employ equipment, including Unmanned Aerial Vehicles , military-grade night-vision and thermal binoculars, ground sensors and camera traps that detect human seismic activity or motion and send automatic notifications to ground response teams. Typically,

9720-461: The rhino. Poachers smear rat poison on salt and mineral deposits, which rhinos often lick to revitalise certain parts of their digestive system. The poison is lethal once ingested by the rhino. As of 2020, 80% of the world's remaining rhinos are found in South Africa, which has become the epicentre of rhino poaching. A surge in rhino poaching was observed in 2008 and again in 2012. The number of rhino deaths due to poaching then increased sharply to

9828-579: The rising demand from South East Asian countries, particularly Vietnam and China . Rhino horn is estimated to be valued at $ 60,000 per 1 pound (0.45 kg) on the black market, a value approximately three times that of gold. The history of rhino poaching in southern Africa dates to the colonial era when the British went ashore at the current Cape Town in 1647. Since then, rhino populations have fluctuated and there have been multiple periods when different species of rhino have threatened extinction . During

9936-501: The sanctuary denies it was on their property. In April 2023, four rhinos were shot, two of them fatally, though the motive is unknown as the horns were still intact. 22°14′05″S 26°43′12″E  /  22.23472°S 26.72000°E  / -22.23472; 26.72000 Rhinoceros poaching in Southern Africa Rhinoceros poaching in southern Africa is the illegal act of slaughtering rhinoceros in

10044-533: The sanctuary include the helmeted guineafowl and the lappet-faced vulture . The main conservation project undertaken by Khama Rhino Sanctuary is the rhino breeding program. As of 2014, 28 rhinos had been relocated to other wilderness areas in Southern Africa. The Sanctuary's website reports that its long-term goal is to "create an environment in which Black and White Rhino[s] can breed safely" and to reintroduce them into their natural habitats. The first black rhino

10152-427: The southern African countries of Namibia, Botswana, Zimbabwe and South Africa, where most of Africa's rhinos live. The most common reason for rhino poaching is to meet the high demand for their horns in Asian countries, where the horn is predominantly used in Traditional Chinese Medicine but is increasingly being used as a symbol of wealth and prosperity. In previous generations, the most common rhino poaching activity

10260-460: The species is no longer able to survive and becomes extinct. This may occur by direct effects, such as the environment becoming toxic , or indirectly, by limiting a species' ability to compete effectively for diminished resources or against new competitor species. Habitat destruction, particularly the removal of vegetation that stabilizes soil, enhances erosion and diminishes nutrient availability in terrestrial ecosystems. This degradation can lead to

10368-430: The sudden introduction of human beings to environments full of animals that had never seen them before and were therefore completely unadapted to their predation techniques. Coextinction refers to the loss of a species due to the extinction of another; for example, the extinction of parasitic insects following the loss of their hosts. Coextinction can also occur when a species loses its pollinator , or to predators in

10476-412: The tiniest microorganism to God, is linked in a continuous chain. The extinction of a species was impossible under this model, as it would create gaps or missing links in the chain and destroy the natural order. Thomas Jefferson was a firm supporter of the great chain of being and an opponent of extinction, famously denying the extinction of the woolly mammoth on the grounds that nature never allows

10584-555: The total extinction of the dodo and the extirpation of indigenous horses to the British Isles. He similarly argued against mass extinctions , believing that any extinction must be a gradual process. Lyell also showed that Cuvier's original interpretation of the Parisian strata was incorrect. Instead of the catastrophic floods inferred by Cuvier, Lyell demonstrated that patterns of saltwater and freshwater deposits , like those seen in

10692-577: The wider scientific community of his theory. Cuvier was a well-regarded geologist, lauded for his ability to reconstruct the anatomy of an unknown species from a few fragments of bone. His primary evidence for extinction came from mammoth skulls found in the Paris basin . Cuvier recognized them as distinct from any known living species of elephant, and argued that it was highly unlikely such an enormous animal would go undiscovered. In 1812, Cuvier, along with Alexandre Brongniart and Geoffroy Saint-Hilaire , mapped

10800-602: Was born in 2007 and two white rhinos were born in 2009. The rhinos within the sanctuary are secured by anti-poaching patrols carried out by the rangers and the Botswana Defense Force . By 2014, no rhinos had been poached on the land since the sanctuary's opening. After nearly 30 years of Khama being a safe haven, however, two white rhinos were reported by the Botswana Department of Wildlife and National Parks to have been killed by poachers posing as visitors in 2022;

10908-483: Was difficult to disprove. When parts of the world had not been thoroughly examined and charted, scientists could not rule out that animals found only in the fossil record were not simply "hiding" in unexplored regions of the Earth. Georges Cuvier is credited with establishing the modern conception of extinction in a 1796 lecture to the French Institute , though he would spend most of his career trying to convince

11016-465: Was enhanced while participation of the private sector, non-governmental organisations and donors is encouraged. The table below shows the number of rhinos poached in the various provinces of South Africa as well as the rhino deaths due to poaching in the whole of the African continent from 2007 to 2018. From October 2018 to December 2019 thirty-one rhinos (23 white and 8 black) were killed in safari areas in

11124-419: Was hunting for recreational purposes. Because of excessive poaching, rhino populations have decline rapidly since the 1970s, leaving some species critically endangered and facing extinction. Rhino poaching is illegal and there are several organisations in place to save the rhinos and prevent poachers and traffickers. International rhino horn trade is illegal; however, a lucrative black market exists stemming from

11232-736: Was in transit. The men held a permit to transport the horns within Gauteng Province only but were arrested in North West Province. The two men have each received prison sentences which will run concurrently for 25 years. Airport authorities at Hong Kong International Airport seized 24 partial rhino horns (worth an estimated value of £780,000) stored in two cardboard boxes that were in transit to Ho Chi Minh City , Vietnam from Johannesburg , South Africa. OR Tambo International Airport customs authorities seized 36 horns and horn fragments (worth an estimated £1 million) that were sniffed out by

11340-554: Was maintained at a consistently low level during this period. From 2008 to 2015, the demand for rhino horn out of South East Asian countries increased dramatically and was the source of the 90-fold increase in rhino poaching incidents in southern Africa. During this period, poaching statistics continued to grow and in 2014 rhino poaching was at its highest, with an estimated 1,215 rhinos poached in South Africa alone. Between 2015 and 2019, annual poaching figures in South Africa have fallen. The current black rhino and white rhino population

11448-430: Was not until 1982, when David Raup and Jack Sepkoski published their seminal paper on mass extinctions, that Cuvier was vindicated and catastrophic extinction was accepted as an important mechanism . The current understanding of extinction is a synthesis of the cataclysmic extinction events proposed by Cuvier, and the background extinction events proposed by Lyell and Darwin. Extinction is an important research topic in

11556-612: Was recorded at 110. The white rhino population made a recovery due to the intervention of the Africa's oldest nature reserve; the Hluhluwe-Mfolozi Park in KwaZulu-Natal . The sanctuary assisted with the breeding and conservation of the white rhino population. The black rhino population was also able to recover. In the 1950s to the 1960s, the Hluhluwe-iMfolozi Park and Wilderness Foundation founder Dr Ian Player were

11664-571: Was skeptical that catastrophic events of a scale large enough to cause total extinction were possible. In his geological history of the earth titled Hydrogeologie, Lamarck instead argued that the surface of the earth was shaped by gradual erosion and deposition by water, and that species changed over time in response to the changing environment. Charles Lyell , a noted geologist and founder of uniformitarianism , believed that past processes should be understood using present day processes. Like Lamarck, Lyell acknowledged that extinction could occur, noting

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