Local extinction

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Local extinction, also extirpation, is the termination of a species (or other taxon) in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. [1] [2]

Contents

Local extinctions mark a change in the ecology of an area. It has sometimes been followed by a replacement of the species taken from other locations, such as with wolf reintroduction.

Discussion

Glaciation is one factor that leads to local extinction. This was the case during the Pleistocene glaciation event in North America. During this period, most of the native North American species of earthworm were killed in places covered by glaciation. This left them open for colonization by European earthworms brought over in soil from Europe. [3]

Species naturally become extirpated from islands over time. The number of species an island can support is limited by its geographical size. Because many islands were relatively recently formed due to climate change at the end of the Pleistocene when the sea level rose, and these islands most likely had the same complement of species as found on the mainland, counting the species which still survive at present on a statistically large enough amount of islands will give the parameters with which certain groups of species such as plants or birds will become less biodiverse on a given island over a given period of time, depending on its size. The same calculations can also be applied to determine when species will disappear from nature parks ('islands' in many senses), mountain tops and mesas (see sky islands), forest remnants or other such distributional patches. This research also demonstrates that certain species are more prone to extinction than others, a species has an intrinsic extinction-ability (incidence function). [4] [5]

Some species exploit or require transient or disturbed habitats, such as vernal pools, a human gut, or burnt woodland after forest fires, and are characterised by highly fluctuating population numbers and shifting distributional patterns. Many natural ecosystems cycle through a standard succession, pioneer species disappear from a region as the ecosystem matures and reaches a climax community.

A local extinction can be useful for research: in the case of the bay checkerspot butterfly, scientists, including Paul R. Ehrlich, chose not to intervene as a population disappeared from an area in order to study the process. [6]

Many crocodilian species have experienced localized extinction, particularly the saltwater crocodile (Crocodylus porosus), which has been extirpated from Vietnam, Thailand, Java, and many other areas. [7]

Canis lupus Wolf Canis lupus Wildpark Poing-09.jpg
Canis lupus

Major environmental events, such as volcanic eruptions, may lead to large numbers of local extinctions, such as with the 1980 Mount St. Helens eruption, which led to a fern spike extinction.

Bull Kelp Durvillaea potatorum Bull kelp P2153881.JPG
Bull Kelp

Heat waves can lead to local extinction. In New Zealand, during the summer of 2017–2018, sea surface temperatures around parts of South Island exceeded 23 °C (73 °F), which was well above normal. Air temperatures were also high, exceeding 30 °C (86 °F). These high temperatures, coupled with small wave height, led to the local extinction of bull kelp (Durvillaea spp.) from Pile Bay. [8]

Lagoa Santa, a lake located in Lagoa Santa, Brazil, has lost almost 70% of the local fish species over the last 150 years. These include Acestrorhynchus lacustris , Astyanax fasciatus , and Characidium zebra . This could be caused by the introduction of non-native species, like Talapia rendalli , into the lagoon, changes in water level and organic pollution. [9]

Local extinctions can be reversed, in some cases artificially. Wolves are a species that have been reintroduced into parts of their historical range. This has happened with red wolves ( Canis rufus ) in the United States in the late 1980s and also grey wolves in Yellowstone National Park in the mid-1990s. There have been talks of reintroducing wolves in Scotland, Japan, and Mexico. [10]

Subpopulations and stocks

When the local population of a certain species disappears from a certain geographical delimitation, whether fish in a drying pond or an entire ocean, it can be said to be extirpated or locally extinct in that pond or ocean.

A particular total world population can be more or less arbitrarily divided into 'stocks' or 'subpopulations', defined by political or other geographical delimitations. For example, the Cetacean Specialist Group of the International Union for Conservation of Nature (IUCN) has assessed the conservation status of the Black Sea stock of harbour porpoise (Phocoena phocoena) that touches six countries, and COSEWIC, which only assesses the conservation status of wildlife in Canada, even assesses Canadian species that occur in the United States or other countries.

While the IUCN mostly only assesses the global conservation status of species or subspecies, in some older cases it also assessed the risks to certain stocks and populations, in some cases these populations may be genetically distinct. In all, 119 stocks or subpopulations across 69 species had been assessed by the IUCN in 2006. [11] If a local stock or population becomes extinct, the species as a whole has not become extinct, but extirpated from that local area.

Examples of stocks and subdivisions of world populations assessed separately by the IUCN for their conservation status are:

The IUCN also lists countries where assessed species, subspecies or geographic populations are found, and from which countries they have been extirpated or reintroduced.

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">Harbour porpoise</span> Species of mammal

The harbour porpoise is one of eight extant species of porpoise. It is one of the smallest species of cetacean. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar porpoise to whale watchers. This porpoise often ventures up rivers, and has been seen hundreds of kilometres from the sea. The harbour porpoise may be polytypic, with geographically distinct populations representing distinct races: P. p. phocoena in the North Atlantic and West Africa, P. p. relicta in the Black Sea and Sea of Azov, an unnamed population in the northwestern Pacific and P. p. vomerina in the northeastern Pacific.

<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">Saltwater crocodile</span> Reptile of South Asia, Southeast Asia and Oceania

The saltwater crocodile is a crocodilian native to saltwater habitats, brackish wetlands and freshwater rivers from India's east coast across Southeast Asia and the Sundaic region to northern Australia and Micronesia. It has been listed as Least Concern on the IUCN Red List since 1996. It was hunted for its skin throughout its range up to the 1970s, and is threatened by illegal killing and habitat loss. It is regarded as dangerous to humans.

<span class="mw-page-title-main">Madras Crocodile Bank Trust</span> Herpetology research station in Chennai, India

The Madras Crocodile Bank Trust and Centre for Herpetology (MCBT) is a reptile zoo and herpetology research station, located 40 kilometres (25 mi) south of the city of Chennai, in state of Tamil Nadu, India. The centre is both a registered trust and a recognized zoo under the Wildlife (Protection) Act, 1972 and comes under the purview of the Central Zoo Authority, Ministry of Environment, Forest and Climate Change, Government of India. It was established with the aim of saving three Indian endangered species of crocodile—the marsh or mugger crocodile, the saltwater crocodile, and the gharial, which at the time of founding of the trust were all nearing extinction.

<span class="mw-page-title-main">Mugger crocodile</span> Species of crocodile from Asia

The mugger crocodile is a medium-sized broad-snouted crocodile, also known as mugger and marsh crocodile. It is native to freshwater habitats from southern Iran to the Indian subcontinent, where it inhabits marshes, lakes, rivers and artificial ponds. It rarely reaches a body length of 5 m and is a powerful swimmer, but also walks on land in search of suitable waterbodies during the hot season. Both young and adult mugger crocodiles dig burrows to which they retreat when the ambient temperature drops below 5 °C (41 °F) or exceeds 38 °C (100 °F). Females dig holes in the sand as nesting sites and lay up to 46 eggs during the dry season. The sex of hatchlings depends on temperature during incubation. Both parents protect the young for up to one year. They feed on insects, and adults prey on fish, reptiles, birds and mammals.

<span class="mw-page-title-main">Nile crocodile</span> Reptile of Africa

The Nile crocodile is a large crocodilian native to freshwater habitats in Africa, where it is present in 26 countries. It is widely distributed in sub-Saharan Africa, occurring mostly in the eastern, southern, and central regions of the continent, and lives in different types of aquatic environments such as lakes, rivers, swamps, and marshlands. Although capable of living in saline environments, this species is rarely found in saltwater, but occasionally inhabits deltas and brackish lakes. The range of this species once stretched northward throughout the Nile River, as far north as the Nile Delta. Generally, the adult male Nile crocodile is between 3.5 and 5 m in length and weighs 225 to 750 kg. However, specimens exceeding 6.1 m (20 ft) in length and 1,000 kg (2,200 lb) in weight have been recorded. It is the largest freshwater predator in Africa, and may be considered the second-largest extant reptile in the world, after the saltwater crocodile. Size is sexually dimorphic, with females usually about 30% smaller than males. The crocodile has thick, scaly, heavily armoured skin.

<span class="mw-page-title-main">American crocodile</span> Species of crocodile endemic to the Neotropics

The American crocodile is a species of crocodilian found in the Neotropics. It is the most widespread of the four extant species of crocodiles from the Americas, with populations present from South Florida and the coasts of Mexico to as far south as Peru, Ecuador, Colombia, and Venezuela.

<span class="mw-page-title-main">Siamese crocodile</span> Species of reptile

The Siamese crocodile is a medium-sized freshwater crocodile native to Indonesia, Brunei, East Malaysia, Laos, Cambodia, Myanmar, Thailand and Vietnam. The species is critically endangered and already extirpated from many regions. Its other common names include Siamese freshwater crocodile, Singapore small-grain, and soft-belly.

<span class="mw-page-title-main">Conservation status</span> Indication of the chance of extinction

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).

<i>Crocodylus</i> Genus of reptiles

Crocodylus is a genus of true crocodiles in the family Crocodylidae.

<span class="mw-page-title-main">Orinoco crocodile</span> Species of reptile

The Orinoco crocodile is a critically endangered crocodile. Its population is very small, and they can only be found in the Orinoco river basin in Venezuela and Colombia. Extensively hunted for their skins in the 19th and 20th centuries, it is one of the most endangered species of crocodiles. It is a very large species of crocodilian; males have been reported up to 6.8 m in the past, weighing over 900 kg (2,000 lb), but such sizes do not exist today, 5.2 m being a more widely accepted maximum size. A large male today may attain 4.2 m in length and can weigh up to 450 kg (1,000 lb), while females are substantially smaller with the largest likely to weigh around 225 kg (496 lb). Sexual dimorphism is not as profound as in other crocodilian species. The coloration is light even in adults.

<span class="mw-page-title-main">Philippine crocodile</span> Species of crocodile

The Philippine crocodile, also known as the Mindoro crocodile, the Philippine freshwater crocodile, the bukarot in Ilocano, and more generally as a buwaya in most Filipino lowland cultures, is one of two species of crocodiles found in the Philippines; the other is the larger saltwater crocodile (Crocodylus porosus). The Philippine crocodile, the species endemic only to the country, went from data deficient to critically endangered in 2008 from exploitation and unsustainable fishing methods, such as dynamite fishing. Conservation methods are being taken by the Dutch/Filipino Mabuwaya foundation, the Crocodile Conservation Society and the Zoological Institute of HerpaWorld in Mindoro island. It is strictly prohibited to kill a crocodile in the country, and it is punishable by law.

<span class="mw-page-title-main">New Guinea crocodile</span> Species of reptile

The New Guinea crocodile is a small species of crocodile found on the island of New Guinea north of the mountain ridge that runs along the centre of the island. The population found south of the mountain ridge, formerly considered a genetically distinct population, is now considered a distinct species, Hall's New Guinea crocodile. In the past it included the Philippine crocodile, C. n. mindorensis, as a subspecies, but today they are regarded as separate species. The habitat of the New Guinea crocodile is mostly freshwater swamps and lakes. It is most active at night when it feeds on fish and a range of other small animals. A female crocodile lays a clutch of eggs in a nest composed of vegetation and she lies up nearby to guard the nest. There is some degree of parental care for newly hatched juveniles. This crocodile was over-hunted for its valuable skin in the mid 20th century, but conservation measures have since been put in place, it is reared in ranches and the International Union for Conservation of Nature (IUCN) lists it as being of "Least Concern".

<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">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">Crocodile farming in the Philippines</span>

Crocodile farming in the Philippines refers to agricultural industries involving the raising and harvesting of crocodiles for the commercial production of Crocodile meat and crocodile leather.

<span class="mw-page-title-main">Endangered species (IUCN status)</span> Species which have been categorized as very likely to become extinct in the near future

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

  1. ↑ Ladle, Richard; Whittaker, Robert J., eds. (2011). Conservation Biogeography . John Wiley & Sons. p.  61. ISBN   978-1-4443-9811-3.
  2. ↑ Smith-Patten, Brenda D.; Bridge, Eli S.; et al. (14 January 2015). "Is extinction forever?". Public Understanding of Science . 24 (4): 481–495. doi:10.1177/0963662515571489. PMC   4404403 . PMID   25711479.
  3. ↑ Gates, G. E. (May 1949). "Miscellanea Megadrilogica". The American Naturalist. 83 (810): 139–152. doi:10.1086/281596. ISSN   0003-0147. S2CID   222328616.
  4. ↑ Diamond, Jared M. (November 1972). "Biogeographic Kinetics: Estimation of Relaxation Times for Avifaunas of Southwest Pacific Islands" (PDF). Proceedings of the National Academy of Sciences of the USA . 69 (11): 3199–3203. Bibcode:1972PNAS...69.3199D. doi: 10.1073/pnas.69.11.3199 . PMC   389735 . PMID   16592024 . Retrieved 21 November 2021.
  5. ↑ Diamond, Jared M. (1975). "The Island Dilemma: Lessons of Modern Biogeographic Srudies for the Design of Natural Reserves" (PDF). Biological Conservation. 7 (2): 129–146. doi:10.1016/0006-3207(75)90052-X . Retrieved 21 November 2021.
  6. ↑ Holsinger, Kent. "Local extinction Archived 2007-03-11 at the Wayback Machine ". Population Viability Analysis: Bay Checkerspot Butterfly. URL accessed August 11, 2006.
  7. ↑ Webb, Grahame; Manolis, S; Brien, Matthew (2010). Saltwater Crocodile Crocodylus porosus (PDF). Crocodiles. pp. 99–113.[ dead link ]
  8. ↑ Thomsen, Mads S.; Mondardini, Luca; Alestra, Tommaso; Gerrity, Shawn; Tait, Leigh; South, Paul M.; Lilley, Stacie A. & Schiel, David R. (March 2019). "Local Extinction of Bull Kelp (Durvillaea spp.) Due to a Marine Heatwave". Frontiers in Marine Science. 6. doi: 10.3389/fmars.2019.00084 . ISSN   2296-7745.
  9. ↑ Pompeu, Paulo dos Santos; Alves, Carlos Bernardo Mascarenhas (December 2003). "Local fish extinction in a small tropical lake in Brazil". Neotropical Ichthyology. 1 (2): 133–135. doi: 10.1590/S1679-62252003000200008 . ISSN   1679-6225.
  10. ↑ Arts, Koen; Fischer, Anke; Wal, René van der (2016). "Boundaries of the wolf and the wild: a conceptual examination of the relationship between rewilding and animal reintroduction". Restoration Ecology. 24 (1): 27–34. doi:10.1111/rec.12309. ISSN   1526-100X. S2CID   86338008.
  11. ↑ IUCN Red List, search for only stocks and subpopulations [ dead link ]
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