Global map shows new patterns of extinction risk

1 November 2006

A joint news release from Imperial College London and the Natural Environment Research Council

The most detailed world map of mammals, birds and amphibians ever produced shows that endangered species from these groups do not inhabit the same geographical areas, says new research published today.

Contrary to conservationists' previous assumptions, the map shows conclusively that geographical areas with a high concentration of endangered species from one group, do not necessarily have high numbers of endangered species from the others. This new finding has far-reaching implications for conservation planning by governments and NGOs, and their decisions about where to focus conservation spending. These decisions have typically been based on the assumption that investing in an area known to have a high concentration of endangered birds, for example, will also mean that large numbers of endangered mammal and amphibian species will also be protected. The new study shows that basing conservation decisions on just one type of animal can be very misleading.

The study, out in today's issue of Nature journal, is the culmination of many decades of work by field biologists and analysts, during which the planet was divided up into 100km by 100km grids, and all mammal, bird and amphibian species within each grid square were counted, using a variety of pre-existing, but never-before combined, records. The result is a comprehensive worldwide map of all species in these groups, on a finer scale than ever before.

Professor Ian Owens, one of the paper's authors from Imperial College London's Division of Biology, and the Natural Environment Research Council's Centre for Population Biology, said, "For the first time ever this global mapping has divided the planet up into small grid squares to obtain a really detailed picture of biodiversity. By looking at the numbers of endangered mammals, birds and amphibians in these squares, we have been able to see how this real picture varies from assumptions that have previously been made about global biodiversity of endangered species."

Professor Owens adds that this geographical discrepancy in hotspots of endangered species from different groups can be explained by the different factors that threaten mammals, birds and amphibians, "Endangered bird species are often at risk because their habitats are being destroyed. However, different factors entirely may affect mammals such as tigers which are under threat from poachers, and amphibians which are being diminished by diseases brought into their habitat by non-native fish.

"This means that even if a mountainous area has a real problem with endangered amphibians in its creeks and rivers, mammal and bird species in the same are might be flourishing. It's really important not to assume that there are simply a number of hotspots across the globe where everything living there is endangered - the picture is far more complicated, with mammal, bird and amphibian numbers being threatened by different things, in different locations."

Examples of geographical locations in which the distribution of endangered species is different include:

New Zealand is a hot spot for threatened birds because of the danger posed by introduced rats and cats.
Mammals are highly threatened across eastern Africa due to hunting and the bush meat trade
The tropical, rainforest-clad mountains of northern Australia are home to many declining frog species, although the precise causes of these declines often remain enigmatic.

Further information

Danielle Reeves
Press Officer
Imperial College London
Tel: 020 759 42198
Mob: 07803 886248

NERC Press Office
Natural Environment Research Council
Polaris House, North Star Avenue
Swindon, SN2 1EU
Tel: 01793 411561
Mob: 07917 557215

Notes

1. "The global distribution and conservation of rare and threatened vertebrates," Nature, Vol xx, Issue xx, October xx 2006.

Richard Grenyer (1), C. David, L.Orme (2), Sarah F Jackson (3), Gavin H Thomas (4), Richard G Davies (3), T. Jonathan Davies (1), Kate E. Jones (5), Valerie A Olson (5), Robert S Ridgely (6), Pamela C Rasmussen (7), Tzung-Su Ding (8), Peter M Bennett (5), Tim M Blackburn (4), Kevin J Gaston (3), John L Gittleman (1) ad Ian P F Owens (2,9)

Department of Biology, Gilmer Hall, University of Virginia, Charlottesville, Virginia, VA 22904, USA
Division of Biology, Imperial College London, Silwood Park, Ascot, Berkshire, SL5 7PY, UK
Biodiversity & Macroecology Group, Department of Animal & Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
Institute of Zoology, Zoological Society of London, London NW1 4RY, UK
Academy of Natural Sciences, Philadelphia, PA 19103, USA
Michigan State University Museum and Department of Zoology, MI 48824-1045, USA
School of Forestry & Resource Conservation, National Taiwan University, Taipei 106, Taiwan
Natural Environment Research Council Centre for Population Biology, Silwood Park, Ascot, Berkshire, SL5 7PY, UK

2. The research was funded by a consortium grant from the Natural Environment Research Council.

3. The Natural Environment Research Council is one of the UK's research councils. It uses a budget of about £370m a year to fund and carry out impartial scientific research in the sciences of the environment. It is addressing some of the key questions facing mankind, such as global warming, renewable energy and sustainable economic development.

4. Consistently rated in the top three UK university institutions, Imperial College London is a world leading science-based university whose reputation for excellence in teaching and research attracts students (11,000) and staff (6,000) of the highest international quality. Innovative research at the College explores the interface between science, medicine, engineering and management and delivers practical solutions that enhance the quality of life and the environment - underpinned by a dynamic enterprise culture.

Press release: 65/06

Global map shows new patterns of extinction risk

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