A detailed analysis of the well-known IUCN Red List of Threatened Species™ shows 869 species are Extinct or Extinct the Wild. This figure rises to 1,159 if the 290 Critically Endangered species tagged as Possibly Extinct are included. Overall, a minimum of 16,928 species are threatened with extinction. Considering that only 2.7 percent of the 1.8 million described species have been analyzed, this number is a gross underestimate, but it does provide a useful snapshot of what is happening to all forms of life on Earth.
The IUCN analysis, which is published every four years, comes just before the deadline governments set themselves to evaluate how successful they were in achieving the 2010 target to reduce biodiversity loss. The IUCN report, Wildlife in a Changing World, shows the 2010 target will not be met.
The report analyses 44,838 species on the IUCN Red List and presents results by groups of species, geographical regions, and different habitats, such as marine, freshwater and terrestrial.
An increased number of freshwater species have now been assessed, giving a better picture of the dire situation they face. In Europe, for example, 38 percent of all fishes are threatened and 28 percent in Eastern Africa. The high degree of connectivity in freshwater systems, allowing pollution or invasive species to spread rapidly, and the development of water resources with scant regard for the species that live in them, are behind the high level of threat.
In the oceans, the picture is similarly bleak. The report shows that a broad range of marine species are experiencing potentially irreversible loss due to over-fishing, climate change, invasive species, coastal development and pollution. At least 17 percent of the 1,045 shark and ray species, 12.4 percent of groupers and six of the seven marine turtle species are threatened with extinction.
Most noticeably, 27 percent of the 845 species of reef building corals are threatened, 20 percent are Near Threatened and there is not enough data for 17 percent to be assessed. Marine birds are much more threatened that terrestrial ones with 27.5 percent in danger of extinction, compared with 11.8 percent of terrestrial birds.
The report shows nearly one third of amphibians, more than one in eight birds and nearly a quarter of mammals are threatened with extinction. For some plant groups, such as conifers and cycads, the situation is even more serious, with 28 percent and 52 percent threatened respectively. For all these groups, habitat destruction, through agriculture, logging and development, is the main threat and occurs worldwide.
In the case of amphibians, the fungal disease chytridiomycosis is seriously affecting an increasing number of species, complicating conservation efforts. For birds, the highest number of threatened species is found in Brazil and Indonesia, but the highest proportion of threatened or extinct birds is found on oceanic islands. Invasive species and hunting are the main threats. For mammals, unsustainable hunting is the greatest threat after habitat loss. This is having a major impact in Asia, where deforestation is also occurring at a very rapid rate.
Red List Indices make it possible to track trends of extinction risk in groups of species. New indices have been calculated and provide some interesting results. Birds, mammals, amphibians and corals all show a continuing deterioration, with a particularly rapid decline for corals. Red List Indices have also been calculated for amphibian, mammal and bird species used for food and medicine. The results show that bird and mammal species used for food and medicine are much more threatened. The diminishing availability of these resources has an impact on the health and well-being of the people who depend on them directly.