BARCELONA, October 6 – The most comprehensive assessment of the world’s mammals has confirmed an extinction crisis, with almost one in four at risk of disappearing forever, according to The IUCN Red List of Threatened Species.
The new study to assess the world’s mammals shows at least 1,141 of the 5,487 mammals on earth are known to be threatened with extinction. At least 76 mammals have become extinct since 1500. But the results also show conservation can bring species back from the brink of extinction, with five percent of currently threatened mammals showing signs of recovery in the wild.
"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. "We must now set clear targets for the future to reverse this trend to ensure that our enduring legacy is not to wipe out many of our closest relatives."
The real situation could be much worse as 836 mammals are listed as Data Deficient. With better information more species may well prove to be in danger of extinction.
"The reality is that the number of threatened mammals could be as high as 36 percent," says Jan Schipper, of Conservation International and lead author in a forthcoming article in Science. "This indicates that conservation action backed by research is a clear priority for the future, not only to improve the data so that we can evaluate threats to these poorly known species, but to investigate means to recover threatened species and populations."
The results show 188 mammals are in the highest threat category of Critically Endangered, including the Iberian Lynx (Lynx pardinus), which has a population of just 84-143 adults and has continued to decline due to a shortage of its primary prey, the European Rabbit (Oryctolagus cuniculus).
China’s Père David’s Deer (Elaphurus davidianus), is listed as Extinct in the Wild. However, the captive and semi-captive populations have increased in recent years and it is possible that truly wild populations could be re-established soon. It may be too late, however, to save the additional 29 species that have been flagged as Critically Endangered Possibly Extinct, including Cuba’s Little Earth Hutia (Mesocapromys sanfelipensis), which has not been seen in nearly 40 years.
Nearly 450 mammals have been listed as Endangered, including the Tasmanian Devil (Sarcophilus harrisii), which moved from Least Concern to Endangered after the global population declined by more than 60 percent in the last 10 years due to a fatal infectious facial cancer.
The Fishing Cat (Prionailurus viverrinus), found in Southeast Asia, moved from Vulnerable to Endangered due to habitat loss in wetlands. Similarly, the Caspian Seal (Pusa caspica) moved from Vulnerable to Endangered. Its population has declined by 90 percent in the last 100 years due to unsustainable hunting and habitat degradation and is still decreasing.
Habitat loss and degradation affect 40 percent of the world’s mammals. It is most extreme in Central and South America, West, East and Central Africa, Madagascar, and in South and Southeast Asia. Over harvesting is wiping out larger mammals, especially in Southeast Asia, but also in parts of Africa and South America.
The Grey-faced Sengi or Elephant-shrew (Rhynchocyon udzungwensis) is only known from two forests in the Udzungwa Mountains of Tanzania, both of which are fully protected but vulnerable to fires. The species was first described this year and has been placed in the Vulnerable category.
But it is not all bad news. The assessment of the world’s mammals shows that species can recover with concerted conservation efforts.
The Black-footed Ferret (Mustela nigripes) moved from Extinct in the Wild to Endangered after a successful reintroduction by the US Fish and Wildlife Service into eight western states and Mexico from 1991-2008. Similarly, the Wild Horse (Equus ferus) moved from Extinct in the Wild in 1996 to Critically Endangered this year after successful reintroductions started in Mongolia in the early 1990s.
The African Elephant (Loxodonta africana) moved from Vulnerable to Near Threatened, although its status varies considerably across its range. The move reflects the recent and ongoing population increases in major populations in southern and eastern Africa. These increases are big enough to outweigh any decreases that may be taking place elsewhere.
"The longer we wait, the more expensive it will be to prevent future extinctions," says Dr Jane Smart, Head of IUCN’s Species Programme. "We now know what species are threatened, what the threats are and where – we have no more excuses to watch from the sidelines."
More than mammals
Overall, the IUCN Red List now includes 44,838 species, of which 16,928 are threatened with extinction (38 percent). Of these, 3,246 are in the highest category of threat, Critically Endangered, 4,770 are Endangered and 8,912 are Vulnerable to extinction.
New groups of species have appeared on the IUCN Red List for the first time, increasing the diversity and richness of the data. Indian tarantulas, highly prized by collectors and threatened by the international pet trade, have made their first appearance on the IUCN Red List. They face habitat loss due to new roads and settlements. The Rameshwaram Parachute Spider (Poecilotheria hanumavilasumica) has been listed as Critically Endangered as its natural habitat has been almost completely destroyed.
For the first time, all 161 grouper species have been assessed, of which 20 are threatened with extinction. The Squaretail Coral Grouper (Plectropomus areolatus) from the coral reefs of the Indo-Pacific has been listed as Vulnerable. The fish is seen as a luxury live food and is typically fished unsustainably at its spawning aggregations, a major threat for many grouper species.
Amphibians are facing an extinction crisis, with 366 species added to the IUCN Red List this year. There are now 1,983 species (32 percent) either threatened or extinct. In Costa Rica, Holdridge’s Toad (Incilius holdridgei), an endemic species, moved from Critically Endangered to Extinct, as it has not been seen since 1986 despite intensive surveys.
New reptiles assessed this year include the La Palma Giant Lizard (Gallotia auaritae). Found on the Canary Island of La Palma and thought to have become extinct in the last 500 years, it was rediscovered last year and is now listed as Critically Endangered. The Cuban Crocodile (Crocodylus rhombifer) is another Critically Endangered reptile, moved from Endangered because of population declines caused by illicit hunting for its meat and its skin, which is used in clothing.
The Dow Jones Index of biodiversity
The IUCN Sampled Red List Index (SRLI) is a new initiative of the IUCN Red List, developed in collaboration with the Zoological Society of London. It is set to revolutionize our understanding of the conservation status of the world’s species.
The approach takes a randomised sample of species from a taxonomic group to calculate the trends in extinction risk within that group, in much the same way that an exit poll from a polling station can be used to calculate voting trends. This means that it is possible to track the fate of these species, in the same way as the Dow Jones Index tracks the movement of the financial markets.
Although species coverage on the IUCN Red List has increased in number each year, assessments have in general been restricted to the better known species groups such as birds and mammals. As a consequence, until recently the conservation status of less than four percent of the world’s described biodiversity has been known.
It can no longer be considered appropriate to base conservation decisions on such a restricted subset of species and the SRLI, which is more representative of global biodiversity, can be used to provide a broader picture.
"We are now emerging from the dark ages of conservation knowledge, when we relied on data from a highly restricted subset of species," says Dr Jonathan Baillie, Director of Conservation Programmes at the Zoological Society of London (ZSL). "In the future we will expand the scope of our species knowledge to include a far broader range of groups, thus informing and assisting policy makers in a hugely more objective and representative manner."
Designed to broaden the types of species covered in the IUCN Red List, the SRLI uses a sample of at least 1,500 species from selected groups to show trends in extinction risk. All the world’s birds, amphibians and mammals have now been assessed for the IUCN Red List. The first results from the SRLI are revealed this year and include results for reptile species, giving us a clearer indication of the status of terrestrial vertebrates, as well as other less well-known groups such as freshwater crabs.
One of the newly assessed freshwater crab species, the Purple Marsh Crab (Afrithelphusa monodosa) from West Africa, was almost completely unknown to science until recently. The first living specimen was found in 2005 and it has been listed as Endangered because of habitat disturbance and deforestation from agriculture in all parts of the Upper Guinea forest.
In the future the SRLI will sample other lesser-known groups such as beetles, molluscs, mushrooms, lichens and plant species like mosses and liverworts, and flowering plants. Over the coming years this new approach, which could be considered the Dow Jones Index for biodiversity, will enable us to build a clearer picture of the status of all the world’s species, not just the furry and feathered.
"Over the years, the rigour of the IUCN Red List process has built it into the ‘global gold standard’ for monitoring the conservation status and trends of species and the threats they face worldwide," says Dr Holly Dublin, Chair of IUCN’s Species Survival Commission (SSC). "The SSC is the largest and oldest IUCN Commission, its members are proud to contribute their knowledge and expertise to delivering this amazing conservation tool to the world."