Rare species

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A rare species is a group of organisms that are very uncommon, scarce, or infrequently encountered. This designation may be applied to either a plant or animal taxon, and is distinct from the term endangered or threatened. Designation of a rare species may be made by an official body, such as a national government, state, or province. The term more commonly appears without reference to specific criteria. The International Union for Conservation of Nature does not normally make such designations, but may use the term in scientific discussion. [1]


Rarity rests on a specific species being represented by a small number of organisms worldwide, usually fewer than 10,000. However, a species having a very narrow endemic range or fragmented habitat also influences the concept. [2] [3] Almost 75% of known species can be classified as "rare". [4]

Rare species are species with small populations. Many will move into the endangered or vulnerable category if the negative factors affecting them continue to operate. Well-known examples of rare species - because these are large terrestrial animals - include the Himalayan brown bear, Fennec fox, Wild Asiatic buffalo, or the Hornbill.

They are not endangered yet, but classified as "at risk", [5] [6] although the frontier between these categories is increasingly difficult to draw given the general paucity of data on rare species. This is especially the case in the world Ocean where many 'rare' species not seen for decades may well have gone extinct unnoticed, if they are not already on the verge of extinction like the Mexican Vaquita. [7]

A species may be endangered or vulnerable, but not considered rare if it has a large, dispersed population. IUCN uses the term "rare" as a designation for species found in isolated geographical locations. Rare species are generally considered threatened because a small population size is less likely to recover from ecological disasters.

A rare plant's legal status can be observed through the USDA's Plants Database.

Rare species

NameImage IUCN Red List conservation status Last sightingEstimated population Endemic geographic location
Common name Scientific name Lowest wildlife Highest wildlife Captive Total lowestTotal highest
Ethiopian amphibious rat Nilopegamys plumbeus Critically Endangered, Possibly Extinct 1927 ? ?0?? Distribution of Nilopegamys plumbeus.png
Zuniga's melanomys Melanomys zunigae Critically Endangered, Possibly Extinct1949 ? ?0?? Lima Department, Peru
De Winton's golden mole Cryptochloris wintoni Critically Endangered, Possibly Extinctc.1950 ? ?0?? De Winton's Golden Mole area.png
Northern Sumatran rhinoceros Dicerorhinus sumatrensis lasiotis Jackson rhino.jpg Critically Endangered, Possibly ExtinctAfter 1960 1 ? ?0?? Myanmar & Malay Peninsula, Malaysia / Thailand
Christmas Island shrew Crocidura trichura Critically Endangered, Possibly Extinct1986 ? ?0?? Christmas Island
Cuban ivory-billed woodpecker Campephilus principalis bairdii Campephilus principalis bairdii.jpg Critically Endangered16 March 1987 ? ?0?? Cuba
Garrido's hutia Capromys garridoi Critically Endangered, Possibly Extinct1989 ? ?0??Banco de los Jardins y Jardinillos, Canarreos Archipelago, Cuba
Angel Island mouse Peromyscus guardia Critically Endangered, Possibly Extinct1991 ? ?0?? Mexico - Isla Angel de la Guarda.PNG
Emma's giant rat Uromys emmae Critically Endangered, Possibly Extinct1994 ? ?0?? Owi Island, Indonesia
Wimmer's shrew Crocidura wimmeri Critically Endangered2008 ? ?0?? Wimmer's Shrew area.png
Baiji Lipotes vexillifer Qiqi, a Chinese River Dolphin (Baiji) 26.jpg Critically Endangered, Possibly Extinct2018 ? ?0?? Yangtze Dolphins range.jpg
Puebla deer mouse Peromyscus mekisturus Critically Endangered, Possibly Extinct19480500050 Puebla in Mexico (location map scheme).svg
Dwarf hutia Mesocapromys nana Critically Endangered, Possibly Extinct26 October 19510500050 Zapata Swamp, Cuba
New Zealand greater short-tailed bat Mystacina robusta Mystacina robusta specimen from Auckland Museum.jpg Critically Endangered, Possibly Extinct19670500050 Distribution of Mystacina robusta.png
Kouprey Bos sauveli Saen Monourom Mondul Kiri Cambodia crop.jpg Critically Endangered, Possibly Extinct19880500050 Bos sauveli distribution.svg
Montane monkey-faced bat Pteralopex pulchra Critically Endangered, Possibly Extinct17 May 19900500050 Montane Monkey-faced Bat area.png
San Felipe hutia Mesocapromys sanfelipensis Mesocapromys sanfelipensis drawing.jpg Critically Endangered, Possibly Extinct19780990099Cayo de Juan Garcia & Cayos de San Felipe, Cuba
Gloomy tube-nosed bat Murina tenebrosa Critically Endangered, Possibly Extinct196211011 Tsushima Island & Yakushima, Japan
Fernandina Island Galápagos tortoise Chelonoidis niger phantasticus Critically Endangered, Possibly ExtinctN/A15015 Fernandina Island, Ecuador
Aru flying fox Pteropus aruensis Pteropus aruensis.jpg Critically Endangered, Possibly Extinct18871490149 Trangan, Indonesia
Horrid ground-weaver Nothophantes horridus Horrid Ground Weaver (Nothophantes horridus).jpg Critically EndangeredN/A99 ?99 Cattedown, Plymouth, United Kingdom of Great Britain and Northern Ireland
Northern white rhinoceros Ceratotherium simum cottoni Northern White Rhino.jpg Critically Endangered (Possibly Extinct in the Wild)N/A ? 2 ? 22 22222 Northern white rhino IUCN distribution.svg
One-striped opossum Monodelphis unistriata Critically Endangered, Possibly Extinct9 April 18992100210 Single-striped Opossum area.png
Yangtze giant softshell turtle Rafetus swinhoei Rua Dong Mo.jpg Critically EndangeredN/A24135 Rafetus2.png
American ivory-billed woodpecker Campephilus principalis principalis Ivory-billed Woodpecker.jpg Critically Endangered8 April 20223 (as of 8 April 2022) [8] 3 (as of 8 April 2022) [8] 03(as of 8 April 2022) [8] 3(as of 8 April 2022) [8] Original range of the ivory-billed woodpecker.jpg
Guadalcanal rat Uromys porculus Critically Endangered, Possibly ExtinctBetween 1886 and 188833033 GuadalcanalCloseup.png
Emperor rat Uromys imperator Critically Endangered, Possibly Extinctc. 1960s33033 GuadalcanalCloseup.png
Key tree-cactus Pilosocereus robinii Pilosocereus robinii (30765627841).jpg Critically EndangeredN/A715715 Florida Keys, Mexico, Puerto Rico
Lord Howe Island stick insect Dryococelus australis Lord Howe Island stick insect Dryococelus australis 10June2011 PalmNursery.jpg Critically EndangeredN/A< 10 (as of 3 October 2021) [9] < 10 (as of 3 October 2021) [9] < 10(as of 3 October 2021) [9] < 10(as of 3 October 2021) [9] Ball's Pyramid, Australia
Vaquita Phocoena sinus Vaquita2 Olson NOAA crop2.jpg Critically EndangeredN/A10 (as of 5 May 2022) [10] 10 (as of 5 May 2022) [10] 010(as of 5 May 2022) [10] 10(as of 5 May 2022) [10] Cetacea range map Vaquita.PNG
Saola Pseudoryx nghetinhensis Pseudoryx nghetinhensis, b.PNG Critically Endangered201320 (as of 30 October 2021) [11] < 100 (as of 20 August 2021) [12] 0 [13] 20(as of 30 October 2021) [11] < 100(as of 20 August 2021) [12] Pseudoryx nghetinhensis distribution.png
Telefomin cuscus Phalanger matanim Critically Endangered, Possibly Extinct1997404004040 Telefomin Cuscus area.png
Gobi bear Ursus arctos gobiensis Ursus arctos gobiensis.jpg Critically EndangeredN/A51 (as of 27 May 2022) [14] 51 (as of 27 May 2022) [14] 0 [15] 51(as of 27 May 2022) [14] 51(as of 27 May 2022) [14] Gobi desert en.jpg
Māui dolphin Cephalorhynchus hectori maui Two Maui's dolphins.jpg Critically EndangeredN/A55555555 Maui's dolphin range net ban.jpg
Cat Ba langur Trachypithecus poliocephalus Cat Ba Langur 9.jpg Critically EndangeredN/A656765(as of March 2018) [16] 67(as of March 2018) [16] White-headed Langur area.png
Indonesian Javan rhinoceros Rhinoceros sondaicus sondaicus Rhinoceros sondaicus in London Zoo.jpg Critically EndangeredN/A76 (as of 20 September 2022) [17] 76 (as of 20 September 2022) [17] 076(as of 20 September 2022) [17] 76(as of 20 September 2022) [17] Javan Rhino Range.svg
Western Sumatran rhinoceros Dicerorhinus sumatrensis sumatrensis Sumatran Rhinoceros Way Kambas 2008.jpg Critically EndangeredN/A75 (as of 18 December 2022) [18] 85 (as of 18 December 2022) [18] 108595 Sumatran Rhino range.svg
Alagoas curassow Mitu mitu Mitu mitu 1838.jpg Extinct in the wildN/A0130130130 Mitu mitu map.svg
Kākāpō Strigops habroptilus Strigops habroptilus 1304539.jpg Critically EndangeredN/A149149149149 Anchor Island, Codfish Island / Whenua Hou, Little Barrier Island and Maud Island, New Zealand
Philippine eagle Pithecophaga jefferyi Inbound9197685917307947885.jpg Critically EndangeredN/A200 breeding pairs 200 breeding pairs200 breeding pairs200 breeding pairs Phileagle rangemap.png
Cross River gorilla Gorilla gorilla diehli Cross river gorilla.jpg Critically EndangeredN/A2003000200300 Distibucion gorilla.png
Bornean rhinoceros Dicerorhinus sumatrensis harrissoni 0515rhino01.jpg Critically EndangeredN/A< 250 (as of 24 February 2020) [19] < 250 (as of 24 February 2020) [19] 0< 250(as of 24 February 2020) [19] < 250(as of 24 February 2020) [19] East Kalimantan, Indonesia & Sarawak, Malaysia
Malabar large-spotted civet Viverra civettina Malabar large-spotted civet (Viverra civettina) DSCN2359 (cut).jpg Critically Endangered, Possibly Extinct19932492490249249 Malabar Large-spotted Civet area.png
Devils Hole pupfish Cyprinodon diabolis Cyprinodon diabolis, males.jpg Critically EndangeredN/A263 (as of 29 September 2022) [20] 300 (as of 11 May 2022) [21] 475(as of 4 May 2022) [22] 475(as of 4 May 2022) [22] Devils Hole, Death Valley National Park, United States of America
North Atlantic right whale Eubalaena glacialis Right Whale "Scoop" (42853281122).jpg Critically EndangeredN/A366366366366 Cypron-Range Eubalaena glacialis.svg
Black softshell turtle Nilssonia nigricans Bostami turtle 5.jpg Critically EndangeredN/A150150300450450 Sultan Bayazid Bastami shrine at Chittagong
California condor Gymnogyps californianus California-condor-gymnogyps-californianus-078 (21196759264).jpg Critically EndangeredN/A446446446446 Gymnogyps californianus.svg
Central rock rat Zyzomys pedunculatus Zyzomys pedunculatus.jpg Critically EndangeredN/A8008000800800 Zyzomys pedunculatus map.svg
Wild Bactrian camel Camelus ferus Wild Bactrian camel on road east of Yarkand.jpg Critically EndangeredN/A950950950950 Camelus ferus distribution.svg
Eastern lowland gorilla Gorilla beringei graueri Eastern lowland gorilla.jpg Critically EndangeredN/A< 5,000 (as of 7 October 2022) [23] < 5,000 (as of 7 October 2022) [23] 1< 5,000 or 5,000< 5,000 or 5,000 Eastern Gorilla area.png


See also

Related Research Articles

<span class="mw-page-title-main">IUCN Red List</span> Inventory of the global conservation status of biological species

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological species. A series of Regional Red Lists, which assess the risk of extinction to species within a political management unit, are also produced by countries and organizations.

<span class="mw-page-title-main">Javan rhinoceros</span> Rare species of rhinoceros from Asia

The Javan rhinoceros, Javan rhino, Sunda rhinoceros or lesser one-horned rhinoceros is a critically endangered member of the genus Rhinoceros, of the rhinoceros family, Rhinocerotidae, and one of the five remaining extant rhinoceros species across South Asia and Africa. The Javan rhinoceros is one of the smallest rhinoceros species, along with the Sumatran, or "hairy", rhinoceros. They are superficially similar to Indian one-horned rhinos, as they have plate-like, "armored" protective skin folds, but are slightly smaller in size, at just 3.1–3.2 m (10–10 ft) long and 1.4–1.7 m (4.6–5.6 ft) tall, on average. The heaviest specimens weigh around 2,300 kg/2.3 tonnes, similar to an African black rhinoceros. However, unlike the long and potentially lethal horns of the black or white rhinoceroses of Africa, the Javan species' single, somewhat blunted horn is usually shorter than 25 cm (9.8 in).

<span class="mw-page-title-main">Black rhinoceros</span> Species of mammal

The black rhinoceros, black rhino or hook-lipped rhinoceros is a species of rhinoceros, native to eastern and southern Africa including Angola, Botswana, Kenya, Malawi, Mozambique, Namibia, South Africa, Eswatini, Tanzania, Zambia, and Zimbabwe. Although the species is referred to as black, its colours vary from brown to grey. It is the only extant species of the genus Diceros.

<span class="mw-page-title-main">Vaquita</span> Species of porpoise

The vaquita is a species of porpoise endemic to the northern end of the Gulf of California in Baja California, Mexico. Reaching a maximum body length of 150 cm (4.9 ft) (females) or 140 cm (4.6 ft) (males), it is the smallest of all living cetaceans.

<span class="mw-page-title-main">Species reintroduction</span> Wildlife conservation technique

Species reintroduction is the deliberate release of a species into the wild, from captivity or other areas where the organism is capable of survival. The goal of species reintroduction is to establish a healthy, genetically diverse, self-sustaining population to an area where it has been extirpated, or to augment an existing population. Species that may be eligible for reintroduction are typically threatened or endangered in the wild. However, reintroduction of a species can also be for pest control; for example, wolves being reintroduced to a wild area to curb an overpopulation of deer. Because reintroduction may involve returning native species to localities where they had been extirpated, some prefer the term "reestablishment".

<span class="mw-page-title-main">Threatened species</span> IUCN conservation category

Threatened species are any species which are vulnerable to extinction in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of critical depensation, a mathematical measure of biomass related to population growth rate. This quantitative metric is one method of evaluating the degree of endangerment without direct reference to human activity.

<span class="mw-page-title-main">Sumatran rhinoceros</span> Critically Endangered species of small Asian rhinoceros

The Sumatran rhinoceros, also known as the Sumatran rhino, hairy rhinoceros or Asian two-horned rhinoceros, is a rare member of the family Rhinocerotidae and one of five extant species of rhinoceros; it is the only extant species of the genus Dicerorhinus. It is the smallest rhinoceros, although it is still a large mammal; it stands 112–145 cm (44–57 in) high at the shoulder, with a head-and-body length of 2.36–3.18 m and a tail of 35–70 cm (14–28 in). The weight is reported to range from 500–1,000 kg (1,100–2,200 lb), averaging 700–800 kg (1,540–1,760 lb). Like both African species, it has two horns; the larger is the nasal horn, typically 15–25 cm (5.9–9.8 in), while the other horn is typically a stub. A coat of reddish-brown hair covers most of the Sumatran rhino's body.

<span class="mw-page-title-main">White rhinoceros</span> Largest rhinoceros species

The white rhinoceros, white rhino or square-lipped rhinoceros is the largest extant species of rhinoceros. It has a wide mouth used for grazing and is the most social of all rhino species. The white rhinoceros consists of two subspecies: the southern white rhinoceros, with an estimated 16,803 wild-living animals, and the much rarer northern white rhinoceros. The northern subspecies has very few remaining individuals, with only two confirmed left in 2018, both in captivity. Sudan, the world's last known male Northern white rhinoceros, died in Kenya on 19 March 2018 at age 45.

<span class="mw-page-title-main">Conservation status</span> Indication of the chance of a species extinction, regardless of authority used

The conservation status of a group of organisms indicates whether the group still exists and how likely the group is to become extinct in the near future. Many factors are taken into account when assessing conservation status: not simply the number of individuals remaining, but the overall increase or decrease in the population over time, breeding success rates, and known threats. Various systems of conservation status are in use at international, multi-country, national and local levels, as well as for consumer use such as sustainable seafood advisory lists and certification. The two international systems are by the International Union for Conservation of Nature (IUCN) and The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

<span class="mw-page-title-main">Northern white rhinoceros</span> Subspecies of white rhinoceros

The northern white rhinoceros or northern white rhino is one of two subspecies of the white rhinoceros. This subspecies is a grazer in grasslands and savanna woodlands. Formerly found in several countries in East and Central Africa south of the Sahara, since 19 March 2018, there are only two known rhinos of this subspecies left, named Najin and Fatu, both of which are female; barring the existence of unknown or misclassified male northern white rhinos elsewhere in Africa, this makes the subspecies functionally extinct. The two female rhinos belong to the Dvůr Králové Zoo in the Czech Republic but live in the Ol Pejeta Conservancy in Kenya where they are protected round-the-clock by armed guards.

<span class="mw-page-title-main">Critically Endangered</span> IUCN conservation category

An IUCN Red List Critically Endangered species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of the 157,190 species currently on the IUCN Red List, 9,760 of those are listed as Critically Endangered, with 1,302 being possibly extinct and 67 possibly extinct in the wild.

<span class="mw-page-title-main">Western black rhinoceros</span> Extinct subspecies of mammal

The western black rhinoceros or West African black rhinoceros is an extinct subspecies of the black rhinoceros. It was declared extinct by the IUCN in 2011. The western black rhinoceros was believed to have been genetically different from other rhino subspecies. It was once widespread in the savanna of sub-Saharan Africa, but its numbers declined due to poaching. The western black rhinoceros resided primarily in Cameroon, but surveys since 2006 have failed to locate any individuals.

<span class="mw-page-title-main">Functional extinction</span> End of viability for a population

Functional extinction is the extinction of a species or other taxon such that:

  1. It disappears from the fossil record, or historic reports of its existence cease;
  2. The reduced population no longer plays a significant role in ecosystem function;
  3. The population is no longer viable. There are no individuals able to reproduce, or the small population of breeding individuals will not be able to sustain itself due to inbreeding depression and genetic drift, which leads to a loss of fitness.
<span class="mw-page-title-main">Wildlife of Vietnam</span>

The wildlife of Vietnam is rich in flora and fauna as reflected by its unique biodiversity. Saola, rare and antelope-like animal categorized under the bovine subfamily, was found in 1992 in Vũ Quang National Park. In the 1990s, three other muntjac species, the deer-like Truong Son muntjac, giant muntjac and Pu Hoat muntjac, were also discovered. Conservation protection and scientific studies of the ecology of Vietnam, particularly in the protected forest areas, have been given priority attention by the Government of Vietnam. Laws were enacted to set up Xuân Thủy Wetland National Park, four UNESCO Biosphere Reserves, and Hạ Long Bay and Phong Nha-Kẻ Bàng National Parks; the last two are also designated as UNESCO World Heritage Sites.

<span class="mw-page-title-main">Extinct in the wild</span> IUCN conservation category

A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as only consisting of living members kept in captivity or as a naturalized population outside its historic range. Classification requires exhaustive surveys conducted within the species' known habitat with consideration given to seasonality, time of day, and life cycle. Once a species is classified as EW, the only way for it to be downgraded is through reintroduction.

Francesco Romano Nardelli is an Italian naturalist who has dedicated his life to the protection and conservation of endangered species. He is also the co-founder, with John Aspinall, of the Sumatran Rhino Project, one of the most important coordinated efforts to save a critically endangered species.

<span class="mw-page-title-main">Endangered species</span> Species of organisms facing a very high risk of extinction

An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, and invasive species. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration.

<span class="mw-page-title-main">Bornean rhinoceros</span> Subspecies of Sumatran rhinoceros

The Bornean rhinoceros, also known as the eastern Sumatran rhinoceros or eastern hairy rhinoceros, is one of three subspecies of Sumatran rhinoceros. The subspecies may be functionally extinct, with only one individual, a female named Pahu, surviving in captivity, and held in the state of Sabah. In April 2015, the Malaysian government declared the Bornean rhinoceros to be extinct in the wild in the Malaysian portion of Borneo. However, in March 2016, a young female rhino was captured in East Kalimantan, providing evidence of their continued existence. The International Union for Conservation of Nature (IUCN) classifies the subspecies as critically endangered.


  1. "Assessment Process". www.iucnredlist.org. Retrieved 2017-11-14.
  2. R. MacNally and G. W. Brown, Reptiles and Habitat Fragmentation in the Box-ironbush Forests of Central Victoria, Australia: Predicting Compositional Change and Faunal Nested-ness, Oecologia 128:116–125 (2001).
  3. Prendergast, J. R.; Quinn, R. M.; Lawton, J. H.; Eversham, B. C.; Gibbons, D. W. (1993-09-23). "Rare species, the coincidence of diversity hotspots and conservation strategies". Nature. 365 (6444): 335–337. Bibcode:1993Natur.365..335P. doi:10.1038/365335a0.
  4. Dinerstein, Eric (2013) The Kingdom of Rarities. Island Press. ISBN   9781610911955.
  5. "Rare Species". www.encyclopedia.com. Retrieved 2017-11-15.
  6. "IUCN – A brief history". IUCN. 2017-10-06. Retrieved 2017-11-15.
  7. Briand, Frederic (October 2012). "Species Missing in Action - Rare or Already Extinct?". National Geographic.
  8. 1 2 3 4 Multiple lines of evidence indicate survival of the Ivory-billed Woodpecker in Louisiana
  9. 1 2 3 4 Dryococelus australis (Lord Howe Island Phasmid)
  10. 1 2 3 4 The critically endangered vaquita is not doomed to extinction by inbreeding depression
  11. 1 2 Searching for the Saola in the Annamite Mountains
  12. 1 2 IUCN SSC experts urge for immediate action to find Saola before it’s too late
  13. Saola
  14. 1 2 3 4 Population of endangered Gobi bears exceeds 50 in Mongolia
  15. Gobi Bear Project
  16. 1 2 CAT BA LANGUR
  17. 1 2 3 4 2022 State of the Rhino Report
  18. 1 2 Two Horned Rhino – Sumatran Rhinoceros Profile
  19. 1 2 3 4 Bornean Rhinoceros
  20. Devils Hole pupfish population at 19-year high
  21. Critically endangered pupfish on the rise on 50th anniversary of official monitoring effort
  22. 1 2 The Devil’s Hole pupfish has paddled back from the brink in a hellish desert domain
  23. 1 2 Eastern Lowland Gorilla

Further reading