Last stand in captivity or cultivation: successes and failures

Californian Condor with chickFor several species and subspecies on the planet, captive breeding or cultivation programs and human intervention may be their only hope of survival. Captive breeding and cultivation are the processes of breeding animals or cultivating plants in human controlled environments with restricted settings, such as zoos, botanical gardens, wildlife reserves, and other conservation facilities.

Here we focus on the species and subspecies that are 'extinct in the wild (EW)', meaning that the only known living members are being kept in captivity. Animal and plants that have been preserved in captivity or cultivation after in-situ conservation failed. But can captive populations of 'extinct in the wild' species and subspecies be considered a success of ex-situ conservation? Just maintaining 'extinct in the wild' species in captivity or cultivation is not a solution; although it can be considered a rescue. The Sixth Extinction website's opinion is that the main goal of captive breeding or cultivation programs should be reintroduction, eventually leading to self sustaining wild populations.

What is happening with the species that currently are listed as 'extinct in the wild', and what has happened with those species that have disappeared form that list? In addition to the list of species and subspecies 'extinct in the wild (EW)', this website lists those species and subspecies that have been successfully reintroduced into the wild (see successes), those that have introduced populations that are not yet self sustaining or no reintroduction attempts have yet been made (undecided), and those that became globally extinct while only surviving in captivity or cultivation (see failures). For some species, like the Tasmanian Tiger or the Passenger Pigeon, it is too late.  Hopefully, for others, a captive breeding program may be a new beginning.

Photograph: A reintroduced California Condor protects its chick in a nest cave near Hopper Mountain National Wildlife Refuge, California, USA. Photographed by Joseph Brandt, U.S. Fish and Wildlife Service (USFWS). This file is licensed under the Creative Commons Attribution 2.0 Generic license. A full-resolution version van be found at Flickr and Wikimedia Commons.

Do you know any species or subspecies that should be added to these lists or do you see an error? If so, please contact this website. Help is always welcome!



Arabian OryxSome species and subspecies that once existed only in captivity, can now be seen again in their natural habitat. Captive breeding programs with the goal of reintroduction have existed since the 1950s, with one of the first successful programs being the reintroduction of the Arabian Oryx (Oryx leucoryx). Such a reintroduction can be considered truly successful when the wild population is self sustaining again.

Photograph: An Arabian Oryx (Oryx leucoryx) in Yotvata Hai-Bar Nature Reserve in Israel. The Arabian Oryx became extinct in the wild in 1972, but has been successfully reintroduced into the wild since 1982. Photographed by Shlomi Chetrit (שלומי שטרית) in 2010. This file is licensed under the Creative Commons Attribution 2.5 Generic license. A full-resolution image can be found at Wikimedia Commons.

The subjoined table shows the species and subspecies that have been successfully reintroduced into the wild, meaning that the wild population is self sustaining.

Table 1. Successful reintroduction, wild population self sustaining
Scientific Name Common Name
Last date in the wild
Date reintroduction
TSEW Status IUCN Status
Acanthobrama telavivensis 1 Yarqon Bleak 1999 2006 RI EW
Bison bonasus 2 European Bison
Canis rufus 3 Red Wolf
Equus przewalskii Przewalski Horse
Mustela nigripes 4 Black-footed Ferret
Oryx leucoryx Arabian Oryx



Cyanea superbaBesides the uncontested successful reintroductions there are also several more EW species and subspecies that haven been reintroduced into the wild. However, while these reintroduction attempts sometimes do show some sign of success, it it is not clear that wild populations are self-sustaining and would not disappear again without continuous supplementation and management. Meanwhile, there are still many species and subspecies that only survive in captivity or cultivation for which has no reintroduction has been attempted.

Photograph: A Superb Cyanea photographed by the U.S. Army Environmental Command on 16 March 2010. It is one of 88 endangered species the U.S. Army Garrison Hawaii’s Natural Resource Program is responsible for managing. This species went extinct in the wild in the early 2002, however, due to seed collection efforts, 270 individual plants have been reintroduced into their natural habitat. In 2009, staff found seedlings that had been produced naturally by these outplanted individuals, validating the management techniques used by the program. This photograph is licensed under the Creative Commons Attribution 2.0 Generic license. Full resolution versions can be found at Wikimedia Commons and Flickr.

Table 2. Reintroduction attempted, signs of success, wild population not (yet) self sustaining
Scientific Name Common Name
Last date in the wild
Date reintroduction
TSEW Status IUCN Status
Bromus interruptus Interrupted Brome 1972 2001 EW EW
Cyanea superba superba 5 Superb Cyanea 2002 1999-2001 5
Elaphurus davidianus Pere David Deer
Gallirallus owstoni Guam Rail
Gymnogyps californianus 6 California Condor
Nectophrynoides asperginis Kihansi Spray Toad 2004 (possibly 2005) 2012 RI EW
Oryx dammah Sahara Oryx
Thermosphaeroma thermophilum Socorro Isopod


Table 3. Reintroduction attempted, no signs of success (yet)
Scientific Name Common Name
Last date in the wild
Date reintroduction
TSEW Status IUCN Status
Clermontia peleana peleana 8 Pele Clermontia 2000 2001 8
Commidendrum rotundifolium 9 Bastard Gumwood
2002? 9
Corvus hawaiiensis Hawaiian Crow 2002 1993-1999 EW EW
Lysimachia minoricensis Menorca Loosestrife 1926-1950 1959-1996
Sophora toromiro Toromiro 1960 1995


Table 4. Remains only in captivity, no reintroduction attempted (yet)
Scientific Name Common Name
Last date in the wild
Date reintroduction
TSEW Status IUCN Status
Amphilophus lyonsi Unknown (Cichlid) 2000 -- EW NE
Atelopus zeteki 10 Panamanian Golden Frog 2008 10 -- EW CR
Aylacostoma guaraniticum 11 Unknown (Snail) 1993 -- EW EW
Aylacostoma stigmaticum 11 Unknown (Snail) 1993 -- EW EW
Betula szaferi Unknown Unknown (before 1998) --
Bromus bromoideus Ardennes Brome 1930 -- EW EW
Camelus dromedarius 12 Dromedary Unknown (3000 BCE?) 12 -- EW NE
Ceratotherium simum cottoni Northern White Rhinoceros 2007 (2009?) -- EW CR
Corypha taliera Unknown (Plant) 1979 --
Craugastor punctariolus Bob's Robber Frog 2009 -- EW EN
Cryosophila williamsii Lago Yojoa Palm Unknown (before 1998) --
Cyanea pinnatifida Sharktail Cyanea 2001 --
Cyprinodon alvarezi Potosi Pupfish 1992 -- EW EW
Cyprinodon longidorsalis La Palma Pupfish Unknown (before 1996) -- EW EW
Cyprinodon veronicae Charco Palma Pupfish Unknown -- EW CR
Cyrtandra waiolani Fuzzyflower Cyrtandra 1943 --
Encephalartos brevifoliolatus Escarpment Cycad 2004 --
Encephalartos nubimontanus Blue Cycad Between 2001 and 2004 --
Encephalartos relictus Relictual Cycad 1971 --
Encephalartos woodii Wood's Cycad 1916 --
Erythroxylum echinodendron Unknown (Plant) Unknown (before 1998) --
Euphorbia mayurnathanii Unknown (Plant) Between 1940 - 1998) --
Firmiana major Unknown (Plant) Unknown (before 1998) --
Franklinia alatamaha Franklin Tree 1803 --
Haplochromis ishmaeli Unknown (Cichlid) 1991 -- EW CR
Haplochromis perrieri Unknown (Cichlid) 1980s -- EW CR
Hemiphractus sp. Casque-headed Frog 2009 -- EW NE
Kokia cookei Cooke's Kokio 1918 --
Mammillaria guillauminiana Unknown (Plant) December 1997 --
Mangifera casturi Kalimantan Mango Unknown (before 1998) --
Mangifera rubropetala Sarawak Mango Unknown (before 1998) --
Megupsilon aporus Catarina Pupfish Unknown (before 1996) -- EW EW
Mitu mitu Alagoas Curassow 1984 (possibly 1987-1988) -- EW EW
Nymphaea thermarum Pygmy Rwandan Water Lily 1987 --
Panthera tigris amoyensis South China Tiger 1970s -- EW CR
Partula dentifera Unknown (Snail) 1992-1994 -- EW EW
Partula faba Unknown (Snail) 1992-1994 -- EW EW
Partula hebe Unknown (Snail) 1992-1994 -- EW EW
Partula mirabilis Unknown (Snail) 1977-1980s -- EW EW
Partula mooreana Unknown (Snail) 1977-1980s -- EW EW
Partula nodosa   Tahiti Tree Snail 1977-1980s -- EW EW
Partula rosea Huahine Tree Snail 1990s-2000 -- EW EW
Partula suturalis strigosa Sutural Partula 1977-1980s -- EW EW
Partula suturalis vexillum Sutural Partula 1977-1980s -- EW EW
Partula tohiveana Unknown (Snail) 1977-1980s -- EW EW
Partula taeniata nucleola Unknown (Snail) 1977-1980s -- EW EW
Partula taeniata simulans Unknown (Snail) 1977-1980s -- EW EW
Partula tristis Unknown (Snail) 1992-1994 -- EW EW
Partula varia Unknown (Snail) 1990s-2000 -- EW EW
Rafetus swinhoei Swinhoe's Softshell Turtle 1998 -- EW CR
Rhododendron kanehirai Unknown (Plant) 1984 --
Senecio leucopeplus Unknown (Plant) 2007 --
Skiffia francesae Golden Skiffia 1979 -- EW EW
Stenodus leucichthys Beloribitsa 2004 -- EW EW
Terminalia acuminata Unknown (Plant) 1942 --
Trochetiopsis erythroxylon St. Helena Redwood 1950s --
Xiphophorus couchianus Monterrey Platyfish Before 2006 -- EW CR
Yssichromis "argens" Unknown (Cichlid) Unknown (before 1996) -- EW EW
Zenaida graysoni Socorro Dove 1972 -- EW EW



Thylacine with cubsSeveral species and subspecies became globally extinct while kept in captiviy or cultivation as extinct in the wild. The last living members of these species and subspecies are believed to have died in captivity or cultivation, or been selectively bred into different species. Besides these extinct species, there are also species that are 'functinally extinct' and only survive in captivity. A well-known example was Lonesome George, the sole surviving individual of the Pinta Island Tortoise (Chelonoidis abingdoni), but sadly he died on 24 June 2012.

However, the species and subspecies in the subjoined table does not necessarily represent a failure of captive breeding programs, as in some cases (e.g. the quagga), no attempts were made to breed the animals.

Photo: A Tasmanian Tiger or Thylacine (Thylacinus cynocephalus) with three cubs in Hobart Zoo (Tasmania, Australia) in June 1909. This image is of Australian origin and is now in the public domain because its term of copyright has expired. According to the Australian Copyright Council(ACC), ACC Information Sheet G23 (Duration of copyright) (Feb 2008).

Table 5. Last living member died in captivity or cultivation (or is functionally extinct)
Scientific Name Common Name
Last date in the wild
Date extinction
TSEW Status IUCN Status
Anas oustaleti Mariana mallard 1979 1981 EX NE
Bos primigenius Aurochs 1627 Domesticated (Bos taurus) EX EX
Chelonoidis abingdoni Pinta Island Giant Tortoise 1971 24 June 2012 EX EW
Conuropsis carolinensis Carolina Parakeet December 1913 21 February 1918 EX EX
Dromaius ater King Island Emu 1802 1822 EX EX
Ecnomiohyla rabborum Rabb’s fringe-toed frog  2008 A single male survives EW CR
Ectopistes migratorius Passenger Pigeon 1900 1914 EX EX
Equus ferus ferus Tarpan 1890 1909 EX NE
Equus quagga quagga Quagga 1870s 1883 EX EX
Equus hemionus hemippus Syrian Wild Ass 1927 1928+ EX NE
Gambusia amistadensis Amistad Gambusia 1968 1987 EX EX
Gambusia georgei San Marcos Gambusia 1981 1980s EX EX
Gazella saudiya Saudi Gazelle 1980s -- EX EX
Macropus greyi Toolache Wallaby  1924 1937 EX EX
Melamprosops phaeosoma Po'o-uli 9 September 2004 28 November 2004 PE CR (PE)
Nesiota elliptica Saint Helena Olive 1994 December 2003 EX
Panthera leo leo 13 Barbary Lion 1942 Unknown (possibly survives)13 EX VU
Partula arguta Acute Huahine Tree-Snail 1994 1995 EX EX
Partula labrusca Vine Raiatea Tree Snail 1992 2002 EX EX
Partula turgida   Moorea Tree-Snail 1994 1996 EX EX
Rhodonessa caryophyllacea Pink-headed Duck June 1935 1949 PE CR
Rucervus schomburgki Schomburgk's Deer 1932 1938 EX EX
Thylacinus cynocephalus Tasmanian Tiger 1933 1936 EX EX



  1. Although the IUCN Red List of Threatened Species list the Yarqon Bleak (Acanthobrama telavivensis) as 'Extinct in the wild' (Crivelli 2006; IUCN 2010), about 9,000 laboratory-born fish were introduced to 12 sitesin Israel in 2006-2007. Surveys in 2007-2009 revealed juveniles at most sites (Goren 2010). The "Extinct in the Wild" Yarqon bleak has been successfully returned to nature (Goren 2010).
  2. The last wild population of the Lowland subspecies of European Bison (Bison bonasus bonasus) in Białowieża Forest became extinct in 1919 (Genthe 1918; Sztolcman 1924; Wróblewski 1932; Okołów 1966; Krysiak 1967; Puzec et al. 2002), while the Caucasian subspecies (Bison bonasus caucasicus) survived until 1927 (Heptner et al. 1966; Kirikov 1979; Puzec et al. 2002). The first re-introduction of European bison into the wild was in Białowieża Forest in 1952 (Puzec et al. 2002). Since about 1960 a reproducing population was established (Krasiński 1983; Puzec et al. 2002).
  3. There is still some debate among scientists regarding the validity of Canis rufus as a species. Some claim it may be a naturally occuring hybrid of coyotes (Canis latrans) and grey wolves (Canis lupus), while others claim it is a subspecies of the grey wolf (Kelly et al. 2008; Mulheisen & Csomos 2001; Nowak, 1995, Wayne, 1995).
  4. US federal and state agencies in cooperation with private landowners, conservation groups, Native Americans, and North American zoos, have been actively reintroducing Black-footed Ferrets (Mustela nigripes) back into the wild since 1991. Currently, there are 19 black-footed ferret reintroduction sites in the U.S. states of Wyoming, South Dakota, Montana, Arizona, Colorado, Utah, Kansas, New Mexico, and in Canada and Mexico. In 2008, the IUCN classified the species as "endangered", a substantial improvement since the 1996-assessment when it was considered extinct in the wild, since at that time the species was indeed only surviving in captivity. Nowadays, about 1,000 individual Black-footed Ferrets can be cound in the wild. However, a number of 150-220 ferrets are still being preconditioned and reintroduced into the wild from the captive breeding population. There are a couple of self-sustaining reintrodcution sites, but most of them are not yet self sustaining. (BFRIT 2011; Wikipedia contributors 2011a) However, it is still unclear if any of them will make it long-term (Zippel 2010).
  5. The Hawaiian endemic plant species Cyanea superba became extinct in the wild when the last wild individual at Kahariahaiki was extirpated in 2002. The State of Hawaii has reintroduced this taxon at the Pahole Natural Area Reserve, and The Nature Conservancy of Hawaii has also outplanted more than 150 individuals into 2 fenced exclosures in Honouliuli Preserve. Army outplantings began in 1999, with 251 individuals outplanted at several sites in Kahanahaiki Valley. In 2005, survivorship varied from 35 to 80 percent. Seventy-eight of the plants were mature and beginning to flower in August 2005. Since 2001, 120 individuals have been outplanted in Pahole Gulch. Survivorship in 2005 was just over 60 percent and at least 12 plants had matured. In Kapuna Gulch, individuals were outplanted in 1997 and 1998 by state of Hawaii's Division of Land and Natural Resources staff, with additional individuals outplanted in 2001 by Army staff. As of 2005, a total of 45 reintroduced individuals survived at the Kapuna Gulch outplanting sites, with at least 19 of them observed to be mature in 2004. (USFWS 2007a) In 2009, regeneration of naturally occurring seedlings under outplanted individuals was first observed (OANRP 2009).
  6. The capture of the remaining wild Califonia Condors (Gymnogyps californianus) was completed on Easter Sunday 1987, when AC-9, the last wild condor, was captured. At that time there were only 22 condors in existence, all in captivity (Wikipedia contributors 2011b). A large-scale, integrated captive-breeding and reintroduction programme, managed by The Peregrine Fund (at the World Center for Birds of Prey), Los Angeles Zoo, Oregon Zoo and San Diego Wild Animal Park is preventing extinction in the wild (BirdLife International 2011). As of May 2011 there are 399 individuals living, including 196 in the wild (The Peregrine Fund 2011). Overall survival of released birds has been high, although without the capture, treatment and re-release of lead contaminated birds it is like that rates of mortality in the wild still exceed sustainable levels (BirdLife International 2011). Therefore, The Sixth Extinction website cannot yet classify this reintroduction program as a complete success.
  7. As part of planned reintroduction projects, animals have been released into fenced protected areas in Tunisia (Bou Hedma National Park 1985, Sidi Toui National Park 1999, Oued Dekouk National Park 1999), Morocco (Souss-Massa National Park 1995), and Senegal (Ferlo Faunal Reserve 1998, Guembuel Wildlife Reserve 1999). (Mésochina et al. 2009) However, the IUCN states: "These populations are all maintained in fenced enclosures of varying sizes and are subject to different degrees of management. None is eligible for consideration as a released population for assessment purposes." (IUCN SSC Antelope Specialist Group 2008).
  8. The 'Oha Wai or Pele Clermontia subspecies Clermontia peleana peleana, endemic to Hawaii, became extinct in the wild in 2000. All surviving individual plants of this species originate from one, now dead, wild individual from the Upper Waiakea Forest Preserve, collected in 1992. In 2001 to 2002, 48 individuals were reintroduced, 60 individuals from 2002 to 2003, 12 individuals from 2003 to 2004, and 24 individuals from 2005 to 2006, for a total of 144 reintroduced individuals. In 2007, one of the Olaa Tract outplanted individuals flowered and will be checked for viable seeds, but the remaining reintroduced individuals are not yet reproductive. (USFWS 2008)
  9. Trees of the Bastard Gumwood (Commidendrum rotundifolium) had been successfully established in cultivation at Pounceys in Saint Helena and the ECS Nursery at Scotland and formed the basis of recovery efforts for the species (Cairns-Wicks 2003). Seedlings raised in 2002 from seed from tree 8 at Pounceys had been planted at Barren Ground (Cairns-Wicks 2003). Apparently, the last of this species to survive in cultivation were damaged by gales in 2008 and the survival of the species was in doubt. In 2009, a single suviving Bastard Gumwood was discovered growing on a cliff. In December 2009, Lourens Malan, a horticulturist working for the island's conservation department under the Critical Species Recovery Project, discovered a wild tree growing on a cliff. A local team of botanists, conservationists and volunteers commenced an intensive programme of hand pollination and seed collection of the remaining cultivated tree, while protecting it from insects that may cross-pollinate with nearby false gumwoods (Wikipedia contributors 2010).
  10. The fungal infection, chytridiomycosis, which is an invasive fungal pathogen, reached El Valle, the home of the Panamanian Golden Frog or Golden Arrow Poison Frog (Atelopus zeteki) in 2006. The same year it was filmed for the very last time in the wild by the BBC Natural History Unit for the series Life in Cold Blood by David Attenborough. In 2006, Biologists from the Smithsonian Institute (as well as other institutions) collected the few surviving Panamanian Golden Frogs they could find in the area in order to maintain them in captivity. Since these frogs have been taken into captivity, biologists have unsuccessfully attempted to locate more.  It was last seen in 2008 (K.C. Zippel, personal communitation 2011). Project Golden Frog (PGF) (in Spanish, Proyecto Rana Dorada) seeks to ensure the survival of this frog. When the threat of the chytrid fungus is gone or reduced, PGF hopes to re-introduce captive bred tadpoles in Panamanian national parks. Learn more at (AmphibiaWeb 2011; Lindquist et al. 2007; Nilsson 2011; WPZ 2011)
  11. Before the construction of the Yacyreta Hydroelectric power plant, five Aylacostoma species have been identified Pananá River until 1993 (before impoundment). Although listed as 'extinct in the wild' by the IUCN Red List of Threatened Species (Mansur 2000), only Aylacostoma chloroticum persists in two relictual populations at the upstream section of the reservoir. The species Aylacostoma guaraniticum and Aylacostoma stigmaticum now survive in captive holdings of the Argentine Museum of Natural Science. In the near future the surviving population of Aylacostoma chloroticum may become extinct due a raise in water level that will be undertaken. In order to preserve this species, a conservation program has been developed to propagate Aylacostoma chloroticum in captivity so that they can be reintroduced into presumed adequate locations downstream Yacyreta dam. (Ostrowski de Núñez & Quintana 2008)
  12. The Dromedary or Arabian Camel (Camelus dromedarius) was domesticated arround 3000 BCE, although there is no consensus about the exact date. There are currently almost 13 million domesticated Dromedaries. None survive in the wild in their original range (North Africa and Arabian Peninsula). Escaped feral Dromedary can be found in Australia, where it is an invasive non-native species. This feral population's number is estimated at more than 500,000 in 2004, while current estimates place the population at closer to one million. (Mukasa-Mugerwa 1981; Australian Government 2011; Wikipedia contributors 2011)
  13. The Barbary Lion (Panthera leo leo) is often classified as 'Extinct in the Wild'. Some lions in Rabat Zoo were identified in 1974 by Leyhausen and Hemmer (Leyhausen 1975) as having physical characteristics of the Barbary lion: very clear light iris, rather than brown; mane spreading behind the shoulders and covering the belly right to the groin, high occiput (back of the head), short legs and deep chest (W. York quoted in introduction to Leyhausen 1975) but none appeared absolutely flawless (Leyhausen 1975). The current royal lions in Rabat Zoo have not only the right Barbary looks, but also, very importantly, the right pedigree supported by circumstantial evidence. Although it may not be very solid, the existence of such evidence clearly separates the royal lions from all the other big-maned lions whose pedigrees are untraceable. (Yamaguchi and Haddane, 2002) However, the genetic distinctiveness of the historical Barbary lion has not yet been fully established and the question over whether the famous Royal Lions from Morocco and their descendents are true Barbary lions remains unanswered (Dubach et al. 2005; Yamaguchi 2005; Barnett et al. 2006; Burger and Hemmer 2006; Antunes et al. 2008; Black et al. 2009). Therefore there is no conclusive evidence that true and pure Barbary Lions survive in captivity. However, the Barbary lion is morphologically more distinct than any of the African lion populations (Hemmer, 1978). Because of this, the guidelines of the precautionary principle (Foster et al. 2000) would suggest that reasonable action to conserve diversity is preferable. Until better data can clarify the Barbary lion's distinctiveness, maintaining the Moroccan royal lions and its decendants as a separate captive management unit distinct from other capitive lion populations is appropriate. Scientists have created a Barbary lion stud book. This studbook identifies the surviving individuals, their locations, their interrelatedness and their line of descent from the original Moroccan royal population. (Black et al., 2009; Walker, 2009) These Moroccan royal lions and its decendants are now the focus of The Barbary Lion Project.


The Sixth Extinction Database (TSED)

The Sixth Extinction has created a database (TSED 1.0) with currently all known recent mammal extinctions, possible extinctions, extinctions in the wild, rediscoveries, and more. Later versions of this database will include extinctions from all animal and plant groups. The database is free to download in Excel and OpenDocument formats.

ExcelExcelOpen Document



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Citation: Maas, P.H.J. (2013). Last stand in captivity or cultivation: successes and failures. In: TSEW (). The Sixth Extinction Website. <>. Downloaded on .
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