Extinction Stalks One in Four of the World's Mammals

The new study conducted for the IUCN Red List of Threatened Species for the first time assessed all of the 5,487 mammals on Earth and found that at least 1,141 of them are known to be threatened with extinction.

One of the few remaining Iberian lynx (Photo courtesy Programa de Conservación Ex-Situ del Lince Ibérico)

At least 76 mammals have become extinct since the year 1500.

The real situation could be much worse as 836 mammals are listed as Data Deficient. With better information, scientists may classify even more species as being in danger of extinction.

"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," said Julia Marton-Lefèvre, IUCN director general.

"The reality is that the number of threatened mammals could be as high as 36 percent," said Jan Schipper of Conservation International, lead author in a forthcoming article on the mammal assessment in the journal "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," said Schipper.

The project to assess the world's mammals was conducted with help from more than 1,800 scientists from over 130 countries.

The assessment also indicates that conservation can bring species back from the brink of extinction, with five percent of currently threatened mammals showing signs of recovery in the wild.

"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," said Marton-Lefèvre.

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 between 84 and143 adults and has continued to decline due to a shortage of its primary prey, the European rabbit, Oryctolagus cuniculus.

Hector's dolphin in New Zealand waters (Photo courtesy NZ Dept. Conservation)

Two of the marine mammals teetering on the edge of extinction are found only in New Zealand - the Hector's dolphin, Cephalorhynchus hectori, and the closely related Maui's dolphin, Cephalorhynchus hectori ssp. maui. A mere 111 Maui's dolphins remain, and the species is classified as Critically Endangered on the new Red List.

Gill netting and trawling are killing these dolphins faster than they can breed, says the conservation organization Care for the Wild International. Since the introduction of nylon filament gill nets in the 1970s, Hector's dolphin numbers have dropped by two thirds from some 29,000 to below 8,000. The situation for Maui's dolphins is worse as 90 percent have already been lost and fewer than 30 adult females survive.

These dolphins are falling victim to human economic activities, as are many of the most vulnerable mammals species.

CWI Chief Executive Dr. Barbara Maas, a former employee of New Zealand's Department of Conservation, charged with the protection of Hector's and Maui's dolphins, says, "In May, the government announced extensions to no-fishing zones and improved controls to further Hector's and Maui's dolphin protection. The decision followed years of research and extensive public consultation."

"Fishing industry representatives participated in these discussions from the outset, but last month industry bodies announced that they will take the government to court over the new measures, arguing that jobs and businesses are at risk," Maas said.

It may be too late to save the 29 species that have been flagged as Critically Endangered Possibly Extinct, including a rodent once found in Cuba, the Little Earth Hutia, Mesocapromys sanfelipensis, which has not been seen in nearly 40 years.

The size of a small dog, Tasmanian devils are marsupials that carry their young in a pouch. (Photo courtesy Trowunna Wildlife Sanctuary)

The fishing cat, Prionailurus viverrinus, found in Southeast Asia, moved from Vulnerable to Endangered due to habitat loss in wetlands.

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.

"This massive tabulation of the locations and often precarious situations of the Earth's mammal species spotlights our need for an increased understanding of the regional changes that are the ultimate challenge to the survival of many of these incredible creatures," says Dr. Thomas Skalak, vice president for research at the University of Virginia.

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 U.S. 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.

A Pere David's Deer in the Vancouver Zoo (Photo credit unknown)

Père David's Deer, Elaphurus davidianus, endemic to China, is listed as Extinct in the Wild. However, the captive and semi-captive populations have increased in recent years and the IUCN says it is possible that truly wild populations could be re-established soon.

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."

"No other tool is as valuable for conservation as the Red List, which provides scientists and decision makers with an important set of information, freely available to the public, to improve the effectiveness of our conservation efforts," says Dr. Russell Mittermeier, chair of IUCN's Primate Specialist Group and president of Conservation International.

The mammal assessment was made possible by the volunteer help of IUCN Species Survival Commission's specialist groups and the collaborations between top institutions and universities, including Conservation International, Sapienza Università di Roma, Arizona State University, Texas A&M University, University of Virginia, and the Zoological Society of London.

"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 programs at the Zoological Society of London. "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."

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