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 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 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, is the culmination of many decades of work by field biologists and analysts, during which the planet was divided up into 100km x 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."