University Parks, Oxford

18/06/2009

Animals under Attack

The ‘red list’ of threatened species

The number of species at threat from extinction is critically high and never has our help been needed more to conserve the world's biodiversity.

The ‘red list’ of threatened species is a snapshot of the most endangered animals and is put together by a coalition of bodies led by the International Union for Conservation of Nature (IUCN).

Although we are discovering new species all the time, the list of endangered ones is also ever-increasing. Campaigners say it is not just animals that need protecting but also the habitats they live in.

"Within our lifetime hundreds of species could be lost as a result of our own actions, a frightening sign of what is happening to the ecosystems where they live," says Julia Marton-Lefèvre, IUCN Director General.

See below to find out more about the animal species most at risk or see maps of their locations.

The Tasmanian Devil is now a threatened species, moving from ‘Least Concern’ to ‘Endangered’. The size of a small dog and found only on the Australian island state of Tasmania, it is the largest carnivorous marsupial in the world.

The global population of this species has declined by more than 60% over the last ten years due to a fatal infectious cancer.

Devil Facial Tumour Disease (DFTD) is spread amongst Tasmanian Devils through biting and from sharing the same food. Once infected, the animal develops tumours around the mouth, which interferes with feeding and eventually leads to death by starvation.

Pere David's Deer is extinct in the wild. Known in Chinese as “Milu”, their English name is derived from the French missionary Father Armand David.

The last wild population is thought to have been eaten by troops during the Boxer Revolution at the end of the 19th century. They were reintroduced into China in the late 1980s from captive animals bred in Europe; these reintroduced animals have been managed since then and are not considered as wild.

The captive population in China has increased in recent years, and the possibility remains that free-ranging populations can be established sometime in the near future. At that point, its IUCN ‘red list’ status will need to be reassessed.

The Iberian Lynx has a total population of only 84-143 adults, restricted to areas of Spain and Portugal, qualifying the species as ‘Critically Endangered’.

The continued decline in the species’ population is due in part to the severe depletion of its primary prey, the rabbit. The introduction of myxomatosis to control rabbits in the 1950s decimated the Iberian Lynx’s main food source and caused the population to crash. When rabbit recovery seemed possible, viral haemorrhagic pneumonia then struck.

In an attempt to maintain Iberian Lynx numbers, conservationists have bred and released rabbits, while the wild population has developed a natural immunity to myxomatosis.

Additional threats to the Iberian Lynx include injuries from snares set for rabbits and accidental deaths from speeding vehicles on the expanding road network.

Disease and illegal shooting also threaten the population. The Iberian Lynx is confined to scattered groups in the south-western Iberian Peninsula where its habitat has been severely fragmented by infrastructure improvement, urban and resort development as well as pine and eucalyptus plantations.

The Grey-faced Sengi is a newly-discovered species of elephant shrew from Tanzania. The species is listed as ‘Vulnerable’ because it is known from only two areas which are prone to fires caused by drought and by humans from the expanding settlements nearby.

It belongs to a group of mammals called “Afrotheria” which evolved in Africa over 100 million years ago and whose relatives include elephants, sea cows and hyraxes. Elephant shrews derive their name from of their long, flexible snouts, rather than their genetic relationship to their larger cousins.

The Grey-faced Sengi was only described fully after being caught on film in 2005 in the remote Ndundulu Forest in Tanzania’s Udzungwa Mountains. It is the first new species of giant elephant shrew to be discovered in more than 126 years and is over 25% larger than any other known sengi.

A rapid loss of habitat could quickly push this species into a higher threat category. Although it is found within protected areas, increased human population pressure around the forest edges could have a negative effect on this species. The predicted effects of global climate change will likely further reduce its already fragmented habitat.

The Caspian Seal has moved from ‘Vulnerable’ to ‘Endangered’. It is found throughout the Caspian Sea, using the winter ice sheets as a surface on which to give birth and nurse pups. Its population has declined by 90% over the last 100 years due to unsustainable levels of commercial hunting, habitat degradation and pollution; it is still decreasing.

Since 2005 the number of pups born has plummeted by a catastrophic 60% to just 6,000-7,000. A low survival rate among pups has led researchers to fear there are barely enough breeding females to keep the population viable.

The African Elephant occurs in some 37 countries in sub-Saharan Africa and is found in dense forest, open and closed savannah, grassland and, at considerably lower densities, even in the arid deserts of Namibia and Mali. Poaching for ivory and meat has traditionally been the major threat to the species.

Across the continent, the total population is believed to have suffered a decline of approximately 25% between 1979 and 2007, which falls short of the 30% threshold required for a ‘Vulnerable’ listing. As such, the African Elephant has been downlisted from the ‘Vulnerable’ category to ‘Near Threatened’.

It is believed that the change in status reflects recent and ongoing population increases in major populations in southern and eastern Africa, largely due to the implementation of highly successful conservation efforts, and which have been of sufficient magnitude to outweigh any decreases that may be taking place elsewhere across their vast range.

The Purple Marsh Crab from upper Guinea, West Africa was almost completely unknown to science until recently. Despite a single specimen discovered in 1947, the first living crabs were only collected in 2005 from a small group dwelling in holes in waterlogged farmland.

These unusual long-legged crabs are semi-terrestrial air-breathers, foraging by night and hiding in the shallow water that collects in their burrows during the day. This is one of the five freshwater crab species found only in this region, and their continued survival depends on the protection of their wetland habitat.

Listed as’ Endangered’, the Purple Marsh Crab is increasingly under threat from rainforest being converted for agriculture. The fact that this species is not found in a protected area casts doubt on its long-term survival without conservation action.

Previously, the Wild Horse was listed as ‘Extinct in the Wild’, but as a result of ongoing reintroduction efforts it is now showing signs of improvement and has moved down by a category to ‘Critically Endangered’.

Provided conservation efforts continue and the population continues to improve at its current rate, it may even move into a lower category on its next reassessment. There are currently around 325 free-ranging Wild Horses in Mongolia.

The past decline of this species has been attributed to a variety of threats, including hunting, military activities, climatic change, habitat changes and competition with domestic livestock.

The main current threat to the reintroduced population is hybridization with and the potential for disease transmission from domestic horses. Habitat degradation and predation by wolves also threaten the population.

The Black-footed Ferret from North America is no longer ‘Extinct in the Wild’ after a massive effort to reintroduce captive animals back to parts of its range.

The species is highly dependent on prairie dogs as its source of food; the widespread extermination of prairie dogs throughout the 20th century, and the spread of disease, caused massive declines in the Black-footed Ferret population.

In 1985, the species was on the verge of extinction when its last free-ranging population collapsed from an outbreak of canine distemper. Once widespread in central North America, it now exists only in reintroduced populations and is currently listed as ‘Endangered’.

From 1991 to 2008, a captive breeding programme by the United States Fish and Wildlife Service brought the Black-footed Ferret back to Mexico and eight western states in the US. At present, it is considered self-sustaining at only three locations: two in South Dakota and one in Wyoming.

The Cuban Crocodile is a freshwater crocodile renowned for its leaping ability, which allows it to prey on forest-dwelling mammals. Relatively small in size, it is also thought to be one of the more intelligent crocodiles.

It has changed status from ‘Endangered’ to ‘Critically Endangered’ because of population declines caused by illicit hunting. Its meat is used in restaurants and its skin for clothing.

Hybridization with the American Crocodile (Crocodylus acutus), is a newly-recognized major threat to the Cuban Crocodile, decreasing its genetic identity and already-limited range.

The Ploughshare Tortoise (also called “Agonoka”) was uplisted from ‘Endangered’ to ‘Critically Endangered’ in 2008. This species has a very small range, occurring only around Baly Bay in north-western Madagascar.

The total wild population is estimated at about 600 individuals and is declining. Its current restricted range and past declines are believed to be the result of exploitation (poaching for the international pet trade) and habitat loss caused by deliberate fires.

It is almost certain that the species will become extinct within the next generation (42 years) if the current level of threat continues unabated.

The Rameshwaram Parachute Spider is a species of Indian tarantula assessed for the first time and listed as ‘Critically Endangered’. Found only on the island of Rameshwaram and the nearby mainland, the spider occurs in an area less than 100 square kilometres, of which perhaps six square kilometres are occupied by this species.

The Rameshwaram Parachute Spider lives in palm, casuarina and tamarind plantations, as well as mixed deciduous woodland and sometimes in thatch-roof houses. The total population of this spider is likely to number less than 500 adults.

Its natural habitat has almost completely been destroyed due to the development of plantations for other uses, a major threat to this species. Increased tourism in the last few years has resulted in the conversion of two plantations to tourist developments where at least 70 Rameshwaram Parachute Spiders had previously been observed. All the spiders were killed by loggers while the sites were being razed.

Although it is not found extensively in the international pet trade, a few specimens have been taken out of the country, further reducing this precarious population.

The Squaretail Coral Grouper is a medium-sized grouper found on the coral reefs of the Indian and Pacific oceans. It is listed as ‘Vulnerable’ because of its importance in the luxury live reef food fish trade.

This grouper is taken in massive numbers from its spawning aggregations where adults come together to spawn for short periods each year. The fish are then kept alive during shipment to Hong Kong, the global trade centre for live marine fish.

The huge market for live reef food amongst wealthy consumers in China and in Chinese communities around the world means that demand for this trade almost certainly exceeds the natural capacity of groupers. The Squaretail Coral Grouper cannot be farmed, therefore all fish are caught from the wild.

As a result of this increasingly heavy fishing pressure at spawning aggregations, many have now disappeared from some countries.

The Fergusson Island Striped Possum is found on only one of the D'Entrecasteaux Islands (Fergusson Island) off Papua New Guinea. The species is not well known, but it is thought to be restricted to primary tropical moist forest areas between altitudes of 600 and 1,000 metres.

Its presumed restricted range and reliance on a habitat that is under threat from expanding agriculture has resulted in this possum being assessed as ‘Endangered’. More research is needed to gather data to further refine the status of this species.

The Fishing Cat has changed category from ‘Vulnerable’ to ‘Endangered’ because of the severe decline throughout much of its Asian range over the last decade. It is a medium-sized cat and a skilful swimmer, found mainly in wetland habitats such as swamps, ox-bow lakes, reed beds, tidal creeks and mangrove areas.

Over 45% of protected wetlands in South East Asia are considered threatened, including those that are home to this species: sites such as the estuaries of the Karnataka coast (south-western India), and the deltas of the Irrawaddy, Indus, Mekong and Red rivers.

Threats to the Fishing Cat include human settlement, draining of its habitat for agriculture, pollution, excessive hunting, wood-cutting and over-fishing. In addition, clearance of coastal mangroves over the past decade has been rapid. The depletion of fish stocks from over-fishing is likely to be a significant threat to this species which relies heavily on fish for its survival.

Holdridge’s Toad is a rainforest amphibian species from Costa Rica which has recently been declared ‘Extinct’. In spite of regular and extensive surveys, most recently in 2007, the species has not been seen since 1986.

It is thought that this species may be one of the more recent victims of chitridiomycosis, a fungal disease which has caused widespread declines in amphibians around the world.