David Gower and Mark Wilkinson, NHM Zoology
It is well known that global diversity is generally under threat from factors such as habitat destruction, pollution, climate change, hunting, invasive species and disease. It takes very large collaborative efforts in order to be able to quantify an accurate overview of the latest situation, but this is needed because donors, policy makers and managers want to know to what extent conservation efforts can make a positive impact.
As part of just such an effort we contributed to an article published in the journal Science (Hoffman, M. et al. (2010) Science 330: 1503-1509).The article reported that although an increasing number of the World’s vertebrate species are threatened by extinction, the deterioration would have been at least one-fifth again as much in the absence of conservation efforts.
The Science study analysed up-to-date conservation assessments for nearly 26,000 of the World’s approximately 63,000 named species of vertebrates (fishes, amphibians, reptiles, birds, and mammals). The assessments are in the form of formal categorizations on the International Union for Conservation of Nature’s (IUCN) “Red List” (www.iucnredlist.org) - the widely accepted 'standard’ for determining species’ risk of extinction.
Balebreviceps hillmani, a threatened amphibian from the Bale Mountains, Ethiopia. [photo by DJ Gower]
Analyses of the Red List data revealed that 20% of vertebrates are classified as Threatened, with this percentage increasing. On average, 52 species of mammals, birds, and amphibians move one category closer to extinction every year (there are eight categories in all). However, of the 1,000 or so species that had undergone a change in their categorization in recent years, about 7% underwent an improvement in status, and almost all of these are part of conservation projects. Thus, in the absence of conservation effort, many more vertebrates would have slipped closer to extinction. Most of these improving vertebrate species are birds and mammals – those groups most often targeted by conservation projects. Only four species of amphibians have improved in status, and more than 40% of this group is threatened; so much remains to be done.
Vertebrates are generally very visible, often charismatic (and vital) components of ecosystems, and they commonly comprise conservation ‘flagship’ species, frequently with high cultural value. However, vertebrates comprise only 3% or so of known organismal species. The conservation status of many non-vertebrates has yet to be determined based on Red List criteria.
The Science paper was authored by a whopping 174 scientists. Like many of these researchers, we played a primary coordinating role that facilitated completion of the dataset. In particular, we finalized Red List assessments for all species of caecilian amphibians (in a workshop held at the NHM), and for some burrowing snakes. Museum science is essential for understanding species’ conservation status because its core business is the taxonomic and ecological work that underpins all other studies of life.
The Science paper was announced in a press release to coincide with the release of the latest Red List update at the Tenth Conference of the Parties to the Convention on Biological Diversity, Nagoya, Japan, October 2010. The paper ends with the following statements: “The 2010 biodiversity target may not have been met, but conservation efforts have not been a failure. The challenge is to remedy the current shortfall in conservation action to halt the attrition of global biodiversity.”
David Gower and Mark Wilkinson are Researchers in the Herpetology Research Group, NHM Department of Zoology
