Local extinction

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

Local extinctions may be followed by a replacement of the species taken from other locations; wolf reintroduction is an example of this.


Local extinctions mark a change in the ecology of an area.

The area of study chosen may reflect a natural subpopulation, political boundaries, or both. The Cetacean Specialist Group of the IUCN has assessed the threat of a local extinction of the Black Sea stock of Harbour Porpoise (Phocoena phocoena) that touches six different countries. COSEWIC, by contrast, investigates wildlife only in Canada, so assesses only the risk of a Canadian local extinction even for species that cross into the United States or other countries. Other subpopulations may be naturally divided by political or country boundaries.

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.

Often a subpopulation of a species will also be a subspecies. For example, the recent disappearance of the Black Rhinoceros (Diceros bicornis) from Cameroon spells not only the local extinction of rhinoceroses in Cameroon, but also the global extinction of the Western Black Rhinoceros (Diceros bicornis longipes).

In at least one case, scientists have found a local extinction useful for research: In the case of the Bay checkerspot butterfly, scientists, including Paul R. Ehrlich, chose not to intervene in a local extinction, using it to study the danger to the world population.[2] However, similar studies are not carried out where a global population is at risk.

IUCN subpopulation and stock assessments

While the World Conservation Union (IUCN) mostly only categorizes whole species or subspecies, assessing the global risk of extinction, in some cases it also assesses the risks to stocks and populations, especially to preserve genetic diversity. In all, 119 stocks or subpopulations across 69 species have been assessed by the IUCN in 2006.[3]

Examples of stocks and populations assessed by the IUCN for the threat of local extinction:

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

The IUCN has only three entries for subpopulations that have become extinct[4]the Aral Sea stock of Ship sturgeon (Acipenser nudiventris); the Adriatic Sea stock of Beluga (Huso huso); and the Mexican subpopulation of Wolf (Canis lupus), which is extinct in the wild. No plant or fungi subpopulations have been assessed by the IUCN.

Local extinction events

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.

See also


  1. ^ Ladle, Richard; Whittaker, Robert J., eds. (2011). Conservation Biogeography. John Wiley & Sons. p. 61. ISBN 9781444398113.
  2. ^ Holsinger, Kent. "Local extinction Archived 2007-03-11 at the Wayback Machine". Population Viability Analysis: Bay Checkerspot Butterfly. URL accessed August 11, 2006.
  3. ^ IUCN Red List, search for only stocks and subpopulations [1]
  4. ^ IUCN Red List, search for extinct stocks and populations: [2]
Archontophoenix cunninghamiana

Archontophoenix cunninghamiana (Bangalow palm, king palm, Illawara palm, piccabben, piccabeen) is an Australian palm. It can grow over 20 m tall. Its flower colour is violet and the red fruits are attractive to birds. It flowers in midsummer and has evergreen foliage.

The Piccabeen Palm grows in the wet subtropics on the sides of Mt Warning Volcano in northern NSW and over the border in Queensland's Lamington National Park, for example. It seeks a good water supply so ravines and grottos are well populated. Its fronds do not create a nesting environment for insects or macrofauna like rodents, so are a tolerable tree for urban environments. Originally in Australia from the landbridge created 45,000 years ago by the receding ocean levels during the last glacial, the probable 'native' environment in prehistory was Indonesia.

It has become a noxious weed in many areas where it has been used as an ornamental plant.

In southern Brazil, it has become an invasive species, profiting from the local extinction of the endangered native palm Euterpe edulis. In New Zealand, A. cunninghamiana could invade native forests, since it has the same ecological requirements as the native nikau palm. The Auckland Regional Council has included A. cunninghamiana on a list of plants requiring further research on their potential to adversely affect the environment.In the United States, the palm is commonly cultivated in California from San Luis Obispo south to the Mexican border and in coastal South Florida.

Caspian tiger

The Caspian tiger (Panthera tigris tigris) was a tiger population which lived from eastern Turkey, Mesopotamia, the Caucasus around the Caspian Sea through Central Asia to northern Afghanistan and Xinjiang in western China. It inhabited sparse forests and riverine corridors in this region until the 1970s. This population was assessed as extinct in 2003.Felis virgata was the scientific name proposed in 1815 by Johann Karl Wilhelm Illiger for this tiger population.

Results of phylogeographic analysis indicate that the Caspian and Siberian tiger populations shared a common continuous geographic distribution until the early 19th century that became fragmented due to human influence.Some Caspian tiger individuals were intermediate in size between Siberian and Bengal tigers.The Caspian tiger was also called Hyrcanian tiger, Turanian tiger, and Babre Mazandaran (Persian: ببرِ مازندران‎), depending on the region of its occurrence.

Colonisation (biology)

Colonisation or colonization is the process in biology by which a species spreads to new areas. Colonisation often refers to successful immigration where a population becomes integrated into a community, having resisted initial local extinction.One classic model in biogeography posits that species must continue to colonize new areas through its life cycle (called a taxon cycle) in order to achieve longevity. Accordingly, colonisation and extinction are key components of island biogeography, a theory that has many applications in ecology, such as metapopulations.


In population dynamics, depensation is the effect on a population (such as a fish stock) whereby, due to certain causes, a decrease in the breeding population (mature individuals) leads to reduced production and survival of eggs or offspring. The causes may include predation levels rising per offspring (given the same level of overall predator pressure) and the allee effect, particularly the reduced likelihood of finding a mate.

Diffusion flame

In combustion, a diffusion flame is a flame in which the oxidizer combines with the fuel by diffusion. As a result, the flame speed is limited by the rate of diffusion. Diffusion flames tend to burn slower and to produce more soot than premixed flames because there may not be sufficient oxidizer for the reaction to go to completion, although there are some exceptions to the rule. The soot typically produced in a diffusion flame becomes incandescent from the heat of the flame and lends the flame its readily identifiable orange-yellow color. Diffusion flames tend to have a less-localized flame front than premixed flames.The contexts for diffusion may vary somewhat. For instance, a candle uses the heat of the flame itself to vaporize its wax fuel and the oxidizer (oxygen) diffuses into the flame from the surrounding air, while a gaslight flame (or the safety flame of a bunsen burner) uses fuel already in the form of a vapor.

Diffusion flames are often studied in counter flow (also called opposed jet) burners. Their interest is due to possible application in the flamelet model for turbulent combustion. Furthermore they provide a convenient way to examine strained flames and flames with holes. These are also known under the name of "edge flames", characterized by a local extinction on their axis because of the high strain rates in the vicinity of the stagnation point.

Diffusion flames have an entirely different appearance in a microgravity environment. There is no convection to carry the hot combustion products away from the fuel source, which results in a spherical flame front, such as in the candle seen here. This is a rare example of a diffusion flame which does not produce much soot and does not therefore have a typical yellow flame.

Ecological extinction

Ecological extinction is "the reduction of a species to such low abundance that, although it is still present in the community, it no longer interacts significantly with other species".Ecological extinction stands out because it is the interaction ecology of a species that is important for conservation work. They state that "unless the species interacts significantly with other species in the community (e.g. it is an important predator, competitor, symbiont, mutualist, or prey) its loss may result in little to no adjustment to the abundance and population structure of other species".This view stems from the neutral model of communities that assumes there is little to no interaction within species unless otherwise proven.

Estes, Duggins, and Rathburn (1989) recognize two other distinct types of extinction:

Global extinction is defined as "the ubiquitous disappearance of a species".

Local extinction is characterized by "the disappearance of a species from part of its natural range".


The word "Eradication" is derived from Latin word "radix" which means "root". It may refer to:

Genocide, the deliberate, systematic destruction of an ethnic, religious or national group of people

Eradication of infectious diseases, the reduction of the global prevalence of an infectious disease in its human or animal host(s) to zero

Intentional local extinction, or extirpation, of an introduced species

Intentional extermination of a population of insects or vermin as part of pest control

A heraldic term denoting a tree that has been uprooted; see Erasure (heraldry)

A song on the album The Price of Existence performed by the death metal band All Shall Perish

"Eradicate the Doubt", a song by Biffy Clyro


The genus Eudyptula ("good little diver") contains two species of penguin, found in southern Australia, Tasmania, and New Zealand (including the Chatham Islands). They are commonly known as the little penguin, little blue penguin, or, in Australia, fairy penguin. In the language of the Māori people of New Zealand, little penguins are known as kororā.For many years, a white-flippered form of the little penguin found only in North Canterbury, New Zealand was considered either a separate species, Eudyptula albosignata, or just a subspecies, Eudyptula minor albosignata. Analysis of mtDNA revealed that Eudyptula falls instead into two groups: a western one, found along the southern coast of Australia and the Otago region of New Zealand, and another found in the rest of New Zealand. These two groups are now considered full species: Eudyptula novaehollandiae in Australia and Otago, and Eudyptula minor elsewhere. E. novaehollandiae probably arrived in New Zealand from Australia less than 500 years ago, following the local extinction of E. minor in Otago.

Interspecific competition

Interspecific competition, in ecology, is a form of competition in which individuals of different species compete for the same resources in an ecosystem (e.g. food or living space). This can be contrasted with interspecific cooperation, a type of symbiosis. Competition between members of the same species is called intraspecific competition.

If a tree species in a dense forest grows taller than surrounding tree species, it is able to absorb more of the incoming sunlight. However, less sunlight is then available for the trees that are shaded by the taller tree, thus interspecific competition. Leopards and lions can also be in interspecific competition, since both species feed on the same prey, and can be negatively impacted by the presence of the other because they will have less food.

Competition is only one of many interacting biotic and abiotic factors that affect community structure. Moreover, competition is not always a straightforward, direct, interaction. Interspecific competition may occur when individuals of two separate species share a limiting resource in the same area. If the resource cannot support both populations, then lowered fecundity, growth, or survival may result in at least one species. Interspecific competition has the potential to alter populations, communities and the evolution of interacting species. On an individual organism level, competition can occur as interference or exploitative competition.

Direct competition has been observed between individuals, populations and species, but there is little evidence that competition has been the driving force in the evolution of large groups. For example, between amphibians, reptiles and mammals.

Japanese squirrel

The Japanese squirrel (Sciurus lis) is a tree squirrel in the genus Sciurus endemic to Japan. The Japanese squirrel's range includes the islands of Honshū, Shikoku, and Kyūshū. Recently, populations on south-western Honshū and Shikoku decreased, and those on Kyūshū disappeared. One of the factors affecting the local extinction of this species seems to be forest fragmentation by humans.

Nauru reed warbler

The Nauru reed warbler (Nauruan: itsirir), Acrocephalus rehsei, is a passerine bird endemic to the island of Nauru in the Pacific Ocean. It is one of only two native breeding land-birds on Nauru and it is the only passerine found on the island. It is related to other Micronesian reed warblers, all of which evolved from one of several radiations of the genus across the Pacific. Related warblers on nearby islands include the Carolinian reed warbler, with which the Nauru species was initially confused, and the nightingale reed warbler, which was formerly sometimes considered the same species.

A medium-sized warbler, the Nauru reed warbler has dark brown upperparts, cream underparts and a long, thin beak. It makes a low, cup-shaped nest into which it lays two or three white eggs, and it feeds on insects. However, details about its behavior and ecology are little known. It is found throughout Nauru, which has changed substantially in recent decades due to phosphate mining. The Nauru reed warbler is potentially threatened by introduced predators and habitat loss, and its small range means that it could be vulnerable to chance occurrences, such as tropical cyclones. Reports of a similar warbler from nearby islands suggest that it might previously have been found elsewhere, but was driven to local extinction by introduced cats.

Oxynoemacheilus tigris

Oxynoemacheilus tigris, the Tigris loach or Halap loach, is a species of stone loach from the genus Oxynoemacheilus. This critically endangered species is endemic to the Queiq River in Turkey where it occurs ins a short stretch of stream between two reservoirs. It formerly occurred in Syria but it has been local extinction from the Syrian portion of the Queiq. This species is threatened by water abstraction and the increased frequency of droughts caused by climate change, most of the Queiq has already been desiccated. It is, however, abundant in the area it is known from where it can be found in reaches of gravel or mud substrate with moderately fast flowing to near standing water.

Pileated gibbon

The pileated gibbon (Hylobates pileatus) is a primate in the gibbon family, Hylobatidae.

The pileated gibbon has sexual dimorphism in fur coloration: males have a purely black fur, while the females have a white-grey colored fur with only the belly and head black. The white and often shaggy hair ring around the head is common to both sexes.

The species has been identified as Endangered, and is listed in CITES Appendix I. Their main threat is habitat destruction, with the wild forest they live in being converted into farmland. This has led to local extinction in some areas. Also, like many other breeds of primate, they are hunted and captured for meat and to be sold into Wildlife smuggling. Many attempts have been made to survey and increase the species' numbers, both concerning their status in the wild, and in zoos.

Plant ecology

Plant ecology is a subdiscipline of ecology which studies the distribution and abundance of plants, the effects of environmental factors upon the abundance of plants, and the interactions among and between plants and other organisms. Examples of these are the distribution of temperate deciduous forests in North America, the effects of drought or flooding upon plant survival, and competition among desert plants for water, or effects of herds of grazing animals upon the composition of grasslands.

A global overview of the Earth's major vegetation types is provided by O.W. Archibold. He recognizes 11 major vegetation types: tropical forests, tropical savannas, arid regions (deserts), Mediterranean ecosystems, temperate forest ecosystems, temperate grasslands, coniferous forests, tundra (both polar and high mountain), terrestrial wetlands, freshwater ecosystems and coastal/marine systems. This breadth of topics shows the complexity of plant ecology, since it includes plants from floating single-celled algae up to large canopy forming trees.

One feature that defines plants is photosynthesis. Photosynthesis is the process of a chemical reactions to create glucose and oxgyen, which is vital for plant life. One of the most important aspects of plant ecology is the role plants have played in creating the oxygenated atmosphere of earth, an event that occurred some 2 billion years ago. It can be dated by the deposition of banded iron formations, distinctive sedimentary rocks with large amounts of iron oxide. At the same time, plants began removing carbon dioxide from the atmosphere, thereby initiating the process of controlling Earth's climate. A long term trend of the Earth has been toward increasing oxygen and decreasing carbon dioxide, and many other events in the Earth's history, like the first movement of life onto land, are likely tied to this sequence of events.One of the early classic books on plant ecology was written by J.E. Weaver and F.E. Clements. It talks broadly about plant communities, and particularly the importance of forces like competition and processes like succession.

Plant ecology can also be divided by levels of organization including plant ecophysiology, plant population ecology, community ecology, ecosystem ecology, landscape ecology and biosphere ecology.The study of plants and vegetation is complicated by their form. First, most plants are rooted in the soil, which makes it difficult to observe and measure nutrient uptake and species interactions. Second, plants often reproduce vegetatively, that is asexually, in a way that makes it difficult to distinguish individual plants. Indeed, the very concept of an individual is doubtful, since even a tree may be regarded as a large collection of linked meristems. Hence, plant ecology and animal ecology have different styles of approach to problems that involve processes like reproduction, dispersal and mutualism. Some plant ecologists have placed considerable emphasis upon trying to treat plant populations as if they were animal populations, focusing on population ecology. Many other ecologists believe that while it is useful to draw upon population ecology to solve certain scientific problems, plants demand that ecologists work with multiple perspectives, appropriate to the problem, the scale and the situation.


Rhabdothamnus solandri, is the only member of the genus Rhabdothamnus, and the only plant from the Gesneriaceae family native to New Zealand. The common names for the plant are New Zealand gloxinia, and in Māori language: taurepo, matata and waiuatua.

Rhabdothamnus solandri is a small shrub growing to 2 metres. It is only found in the North Island in a variety of locations such as forests, near streams, or on banks. R. solandri has a distinctive red and yellow trumpet shaped flower.Due to extinction debt, the future extinction of this shrub is nearly guaranteed. The local extinction of several species of pollinating birds in 1870 has caused a long-term reduction in the reproduction of the shrub species, which requires these birds to produce seeds. However, as the plant is slow-growing and long-lived, its populations persist.

River Carron, Wester Ross

Glen Carron redirects here. For the New Zealand football team, see Glen Carron (soccer).River Carron (Scottish Gaelic: Carrann) is a west coast river in Wester Ross, in the Highlands of Scotland. The river rises in Ledgowan Forest. It gathers its head-streams through Carron Bog, then enters Loch Scaven and flows out from there, passing Loch Dùghaill and eventually reaching Loch Carron.

From Achnashellach the river meanders 19 kilometres (12 mi) southwest through the broad strath of Glen Carron and expands at one part into Loch Doule (or Doughaill). About 4 km (2 mi) further southwest, it enters the Inner Sound at the head of Loch Carron near Strathcarron.

The A890 and a branch of the Highland railway, which extends to Kyle of Lochalsh, runs along part of the river's southeast shore.

Stocking of juvenile Atlantic salmon into the River Carron has brought this fish back from the brink of local extinction. Having made a dramatic recovery, the salmon has contributed to an improvement in the biodiversity of the whole area with kingfishers now established locally, as well as increased numbers of ospreys visiting.

Scarlet macaw

The scarlet macaw (Ara macao) is a large red, yellow, and blue Central and South American parrot, a member of a large group of Neotropical parrots called macaws. It is native to humid evergreen forests of tropical Central and South America. Range extends from south-eastern Mexico to the Peruvian Amazon, Colombia, Bolivia, Venezuela and Brazil in lowlands of 500 m (1,640 ft) (at least formerly) up to 1,000 m (3,281 ft). It has suffered from local extinction through habitat destruction and capture for the parrot trade, but in other areas it remains fairly common. Formerly it ranged north to southern Tamaulipas. It can still be found on the island of Coiba. It is the national bird of Honduras. Like its relative the blue and gold macaw, scarlet macaws are popular birds in aviculture as a result of their striking plumage.

Vancouver Island marmot

The Vancouver Island marmot (Marmota vancouverensis) naturally occurs only in the high mountains of Vancouver Island, in British Columbia. This particular marmot species is large compared to some other marmots, and most other rodents. Marmots as a group are the largest members of the squirrel family, with weights of adults varying from 3 to 7 kg depending on age and time of year.Although endemic to Vancouver Island, Marmota vancouverensis now also resides successfully at several captive breeding centres across Canada as well as several sites on Vancouver Island at which local extinction was observed during the 1990s. This is the result of an ongoing recovery program designed to prevent extinction and restore self-sustaining wild populations of this unique Canadian species. Due to the efforts of the recovery program, the marmot count in the wild increased from less than 30 wild marmots in 2003, to an estimated 250-300 in 2015.

Yellow-eyed penguin

The yellow-eyed penguin (Megadyptes antipodes) or hoiho is a penguin native to New Zealand. Previously thought closely related to the little penguin (Eudyptula minor), molecular research has shown it more closely related to penguins of the genus Eudyptes. Like most other penguins, it is mainly piscivorous.

The species breeds along the eastern and south-eastern coastlines of the South Island of New Zealand, as well as Stewart Island, Auckland Islands, and Campbell Islands. Colonies on the Otago Peninsula are a popular tourist venue, where visitors may closely observe penguins from hides, trenches, or tunnels.

On the New Zealand mainland, the species has experienced a significant decline over the past 20 years. On the Otago Peninsula, numbers have dropped by 75% since the mid-1990s and population trends indicate the possibility of local extinction in the next 20 to 40 years. While the effect of rising ocean temperatures is still being studied, an infectious outbreak in the mid 2000s played a large role in the drop. Human activities at sea (fisheries, pollution) may have an equal if not greater influence on the species' downward trend.

Theories & concepts
Major extinction events
Other extinction events
Extinct species
See also

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