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.
Rare plants can be classified based on the size and distribution of their populations. Some species may be rare because they consist of only a few individuals, are confined to a limited geographic area, or both. Certain rare plants are found sparsely distributed across a wide area. Others might have a large number of individuals that are concentrated in a very small area, such as a single county or canyon. The rarest plants typically have both a small number of individuals and a very limited geographic range.
Assessments of the status of rare plants are conducted using the best available data and consider various factors, including:
A rare plant's legal status can be observed through the USDA's Plants Database.
Name | Image | IUCN Red List conservation status | Last sighting | Estimated population | Endemic geographic location | |||||
---|---|---|---|---|---|---|---|---|---|---|
Common name | Scientific name | Lowest wildlife | Highest wildlife | Captive | Total lowest | Total highest | ||||
Ethiopian amphibious rat | Nilopegamys plumbeus | Critically Endangered, Possibly Extinct | 1927 | ? | ? | 0 | ? | ? | ||
Zuniga's melanomys | Melanomys zunigae | Critically Endangered, Possibly Extinct | 1949 | ? | ? | 0 | ? | ? | Lima Department, Peru | |
De Winton's golden mole | Cryptochloris wintoni | Critically Endangered, Possibly Extinct | c. 1950 | ? | ? | 0 | ? | ? | ||
Northern Sumatran rhinoceros | Dicerorhinus sumatrensis lasiotis | Critically Endangered, Possibly Extinct | After 1960 1 | ? | ? | 0 | ? | ? | Myanmar & Malay Peninsula, Malaysia / Thailand | |
Christmas Island shrew | Crocidura trichura | Critically Endangered, Possibly Extinct | 1986 | ? | ? | 0 | ? | ? | Christmas Island | |
Cuban ivory-billed woodpecker | Campephilus principalis bairdii | Critically Endangered | 16 March 1987 | ? | ? | 0 | ? | ? | Cuba | |
Garrido's hutia | Capromys garridoi | Critically Endangered, Possibly Extinct | 1989 | ? | ? | 0 | ? | ? | Banco de los Jardins y Jardinillos, Canarreos Archipelago, Cuba | |
Angel Island mouse | Peromyscus guardia | Critically Endangered, Possibly Extinct | 1991 | ? | ? | 0 | ? | ? | ||
Emma's giant rat | Uromys emmae | Critically Endangered, Possibly Extinct | 1994 | ? | ? | 0 | ? | ? | Owi Island, Indonesia | |
Wimmer's shrew | Crocidura wimmeri | Critically Endangered | 2008 | ? | ? | 0 | ? | ? | ||
Baiji | Lipotes vexillifer | Critically Endangered, Possibly Extinct | 2018 | ? | ? | 0 | ? | ? | ||
Puebla deer mouse | Peromyscus mekisturus | Critically Endangered, Possibly Extinct | 1948 | 0 | 50 | 0 | 0 | 50 | ||
Dwarf hutia | Mesocapromys nana | Critically Endangered, Possibly Extinct | 26 October 1951 | 0 | 50 | 0 | 0 | 50 | Zapata Swamp, Cuba | |
New Zealand greater short-tailed bat | Mystacina robusta | Critically Endangered, Possibly Extinct | 1967 | 0 | 50 | 0 | 0 | 50 | ||
Kouprey | Bos sauveli | Critically Endangered, Possibly Extinct | 1988 | 0 | 50 | 0 | 0 | 50 | ||
Montane monkey-faced bat | Pteralopex pulchra | Critically Endangered, Possibly Extinct | 17 May 1990 | 0 | 50 | 0 | 0 | 50 | ||
San Felipe hutia | Mesocapromys sanfelipensis | Critically Endangered, Possibly Extinct | 1978 | 0 | 99 | 0 | 0 | 99 | Cayo de Juan Garcia & Cayos de San Felipe, Cuba | |
Gloomy tube-nosed bat | Murina tenebrosa | Critically Endangered, Possibly Extinct | 1962 | 1 | 1 | 0 | 1 | 1 | Tsushima Island & Yakushima, Japan | |
Fernandina Island Galápagos tortoise | Chelonoidis niger phantasticus | Critically Endangered, Possibly Extinct | N/A | 1 | 5 | 0 | 1 | 5 | Fernandina Island, Ecuador | |
Aru flying fox | Pteropus aruensis | Critically Endangered, Possibly Extinct | 1887 | 1 | 49 | 0 | 1 | 49 | Trangan, Indonesia | |
Horrid ground-weaver | Nothophantes horridus | Critically Endangered | N/A | 9 | 9 | ? | 9 | 9 | Cattedown, Plymouth, United Kingdom of Great Britain and Northern Ireland | |
Northern white rhinoceros | Ceratotherium simum cottoni | Critically Endangered (Possibly Extinct in the Wild) | N/A | ? 2 | ? 2 | 2 2 | 22 | 22 | ||
One-striped opossum | Monodelphis unistriata | Critically Endangered, Possibly Extinct | 9 April 1899 | 2 | 10 | 0 | 2 | 10 | ||
Yangtze giant softshell turtle | Rafetus swinhoei | Critically Endangered | N/A | 2 | 4 | 1 | 3 | 5 | ||
American ivory-billed woodpecker | Campephilus principalis principalis | Critically Endangered | 8 April 2022 | 3 (as of 8 April 2022) [9] | 3 (as of 8 April 2022) [9] | 0 | 3(as of 8 April 2022) [9] | 3(as of 8 April 2022) [9] | ||
Guadalcanal rat | Uromys porculus | Critically Endangered, Possibly Extinct | Between 1886 and 1888 | 3 | 3 | 0 | 3 | 3 | ||
Emperor rat | Uromys imperator | Critically Endangered, Possibly Extinct | c. 1960s | 3 | 3 | 0 | 3 | 3 | ||
Key tree-cactus | Pilosocereus robinii | Critically Endangered | N/A | 7 | 15 | 7 | 15 | Florida Keys, Mexico, Puerto Rico | ||
Lord Howe Island stick insect | Dryococelus australis | Critically Endangered | N/A | < 10 (as of 3 October 2021) [10] | < 10 (as of 3 October 2021) [10] | < 10(as of 3 October 2021) [10] | < 10(as of 3 October 2021) [10] | Ball's Pyramid, Australia | ||
Vaquita | Phocoena sinus | Critically Endangered | N/A | 10 (as of 5 May 2022) [11] | 10 (as of 5 May 2022) [11] | 0 | 10(as of 5 May 2022) [11] | 10(as of 5 May 2022) [11] | ||
Saola | Pseudoryx nghetinhensis | Critically Endangered | 2013 | 20 (as of 30 October 2021) [12] | < 100 (as of 20 August 2021) [13] | 0 [14] | 20(as of 30 October 2021) [12] | < 100(as of 20 August 2021) [13] | ||
Telefomin cuscus | Phalanger matanim | Critically Endangered, Possibly Extinct | 1997 | 40 | 40 | 0 | 40 | 40 | ||
Gobi bear | Ursus arctos gobiensis | Critically Endangered | N/A | 51 (as of 27 May 2022) [15] | 51 (as of 27 May 2022) [15] | 0 [16] | 51(as of 27 May 2022) [15] | 51(as of 27 May 2022) [15] | ||
Māui dolphin | Cephalorhynchus hectori maui | Critically Endangered | N/A | 55 | 55 | 55 | 55 | |||
Cat Ba langur | Trachypithecus poliocephalus | Critically Endangered | N/A | 65 | 67 | 65(as of March 2018) [17] | 67(as of March 2018) [17] | |||
Indonesian Javan rhinoceros | Rhinoceros sondaicus sondaicus | Critically Endangered | N/A | 76 (as of 20 September 2022) [18] | 76 (as of 20 September 2022) [18] | 0 | 76(as of 20 September 2022) [18] | 76(as of 20 September 2022) [18] | ||
Western Sumatran rhinoceros | Dicerorhinus sumatrensis sumatrensis | Critically Endangered | N/A | 75 (as of 18 December 2022) [19] | 85 (as of 18 December 2022) [19] | 10 | 85 | 95 | ||
Alagoas curassow | Mitu mitu | Extinct in the wild | N/A | 0 | 130 | 130 | 130 | |||
Kākāpō | Strigops habroptilus | Critically Endangered | N/A | 149 | 149 | 149 | 149 | Anchor Island, Codfish Island / Whenua Hou, Little Barrier Island and Maud Island, New Zealand | ||
Philippine eagle | Pithecophaga jefferyi | Critically Endangered | N/A | 200 breeding pairs | 200 breeding pairs | 200 breeding pairs | 200 breeding pairs | |||
Cross River gorilla | Gorilla gorilla diehli | Critically Endangered | N/A | 200 | 300 | 0 | 200 | 300 | ||
Bornean rhinoceros | Dicerorhinus sumatrensis harrissoni | Critically Endangered | N/A | < 250 (as of 24 February 2020) [20] | < 250 (as of 24 February 2020) [20] | 0 | < 250(as of 24 February 2020) [20] | < 250(as of 24 February 2020) [20] | East Kalimantan, Indonesia & Sarawak, Malaysia | |
Malabar large-spotted civet | Viverra civettina | Critically Endangered, Possibly Extinct | 1993 | 249 | 249 | 0 | 249 | 249 | ||
Devils Hole pupfish | Cyprinodon diabolis | Critically Endangered | N/A | 263 (as of 29 September 2022) [21] | 300 (as of 11 May 2022) [22] | 475(as of 4 May 2022) [23] | 475(as of 4 May 2022) [23] | Devils Hole, Death Valley National Park, United States of America | ||
North Atlantic right whale | Eubalaena glacialis | Critically Endangered | N/A | 366 | 366 | 366 | 366 | |||
Black softshell turtle | Nilssonia nigricans | Critically Endangered | N/A | 150 | 150 | 300 | 450 | 450 | Sultan Bayazid Bastami shrine at Chittagong | |
California condor | Gymnogyps californianus | Critically Endangered | N/A | 446 | 446 | 446 | 446 | |||
Central rock rat | Zyzomys pedunculatus | Critically Endangered | N/A | 800 | 800 | 0 | 800 | 800 | ||
Wild Bactrian camel | Camelus ferus | Critically Endangered | N/A | 950 | 950 | 950 | 950 | |||
Eastern lowland gorilla | Gorilla beringei graueri | Critically Endangered | N/A | < 5,000 (as of 7 October 2022) [24] | < 5,000 (as of 7 October 2022) [24] | 1 | < 5,000 or 5,000 | < 5,000 or 5,000 | ||
Notes:
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.
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 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 a 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).
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.
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.
A threatened species is any species which is 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.
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.
A rhinoceros, commonly abbreviated to rhino, is a member of any of the five extant species of odd-toed ungulates in the family Rhinocerotidae; it can also refer to a member of any of the extinct species of the superfamily Rhinocerotoidea. Two of the extant species are native to Africa, and three to South and Southeast Asia.
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. Sudan, the world's last known male northern white rhinoceros, died in Kenya on 19 March 2018 at age 45.
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).
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.
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.
Functional extinction is the extinction of a species or other taxon such that:
The Threatened Species Protection Act 1995, is an act of the Parliament of Tasmania that provides the statute relating to conservation of flora and fauna. Its long title is An Act to provide for the protection and management of threatened native flora and fauna and to enable and promote the conservation of native flora and fauna. It received the royal assent on 14 November 1995.
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.
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, invasive species, and climate change. 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.
A vulnerable species is a species which has been categorized by the International Union for Conservation of Nature as being threatened with extinction unless the circumstances that are threatening its survival and reproduction improve.
The Bornean rhinoceros, also known as the eastern Sumatran rhinoceros or eastern hairy rhinoceros, is one of three subspecies of Sumatran rhinoceros. The subspecies was feared to 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.
Endangered species, as classified by the International Union for Conservation of Nature (IUCN), are species which have been categorized as very likely to become extinct in their known native ranges in the near future. On the IUCN Red List, endangered is the second-most severe conservation status for wild populations in the IUCN's schema after critically endangered. In 2012, the IUCN Red List featured 3,079 animal and 2,655 plant species as endangered worldwide. The figures for 1998 were 1,102 and 1,197 respectively.