Rare species

Last updated April 13, 2024

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]

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:

Total number of occurrences and the condition of these populations
Population size
Extent of range and area occupied
Trends in population size and distribution over the short and long term
Nature, severity, and urgency of threats
Number of occurrences that are protected and actively managed
Intrinsic vulnerability of the species
Specificity to environmental conditions^[8]

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

Rare species

Name		Image	IUCN Red List conservation status	Last sighting	Estimated population					Endemic geographic location
Common name	Scientific name	Image	IUCN Red List conservation status	Last sighting	Lowest wildlife	Highest wildlife	Captive	Total lowest	Total highest	Endemic geographic location
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:

¹ Last recorded that 7 were in captivity in 1960, in zoos, circuses etc., in the International Zoo Yearbook II. Reports that there is a small population left in Malay Peninsula and Myanmar.
² On 19 March 2018, the last known Northern white rhinoceros male died, but his and another male's sperm was collected and has been used to fertilize eggs as part of a de-extinction effort. Last two known Northern white rhinoceros are both female and held in captivity in the Ol Pejeta Conservancy, Kenya. Unknown if anymore exist in the wildlife and if none exist in the wildlife they would be functionally extinct.

Related Research Articles

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.

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

The Indian rhinoceros, also known as the greater one-horned rhinoceros, great Indian rhinoceros, or Indian rhino for short, is a rhinoceros species native to the Indian subcontinent. It is the second largest extant species of rhinoceros, with adult males weighing 2.07–2.2 tonnes and adult females 1.6 tonnes. The skin is thick and is grey-brown in colour with pinkish skin folds. They have a single horn on their snout that grows to a maximum of 57.2 cm (22.5 in). Their upper legs and shoulders are covered in wart-like bumps. They are nearly hairless, aside from the eyelashes, ear fringes and tail brush.

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:

It disappears from the fossil record, or historic reports of its existence cease;
The reduced population no longer plays a significant role in ecosystem function;
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.

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, 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.

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.

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.

References

↑ "Assessment Process". www.iucnredlist.org. Retrieved 2017-11-14.
↑ 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).
↑ 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.
↑ Dinerstein, Eric (2013) The Kingdom of Rarities. Island Press. ISBN 9781610911955.
↑ "Rare Species". www.encyclopedia.com. Retrieved 2017-11-15.
↑ "IUCN – A brief history". IUCN. 2017-10-06. Archived from the original on 2017-11-15. Retrieved 2017-11-15.
↑ Briand, Frederic (October 2012). "Species Missing in Action - Rare or Already Extinct?". National Geographic.
↑ "What is a rare plant?". www.fs.usda.gov. Retrieved 2024-04-12.
1 2 3 4 Multiple lines of evidence indicate survival of the Ivory-billed Woodpecker in Louisiana
1 2 3 4 Dryococelus australis (Lord Howe Island Phasmid)
1 2 3 4 The critically endangered vaquita is not doomed to extinction by inbreeding depression
1 2 Searching for the Saola in the Annamite Mountains
1 2 IUCN SSC experts urge for immediate action to find Saola before it’s too late
↑ Saola
1 2 3 4 Population of endangered Gobi bears exceeds 50 in Mongolia
↑ Gobi Bear Project
1 2 CAT BA LANGUR
1 2 3 4 2022 State of the Rhino Report
1 2 Two Horned Rhino – Sumatran Rhinoceros Profile
1 2 3 4 Bornean Rhinoceros
↑ Devils Hole pupfish population at 19-year high
↑ Critically endangered pupfish on the rise on 50th anniversary of official monitoring effort
1 2 The Devil’s Hole pupfish has paddled back from the brink in a hellish desert domain
1 2 Eastern Lowland Gorilla

External links

USDA Plant Database

Rare species

Contents

Rare species

See also

Related Research Articles

References

External links

Further reading