Global map shows new patterns of extinction risk

Nov 01, 2006

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.”

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 area 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.

Citation: “The global distribution and conservation of rare and threatened vertebrates,” Nature, 2 November, 2006.

Source: Imperial College London

Explore further: 'Tiger heavyweight' Nepal hosts anti-poaching summit

add to favorites email to friend print save as pdf

Related Stories

Satellite telemetry tracks bearded vultures

Jan 16, 2015

The Pyrenees are home to continental Europe's only wild population of bearded vultures, a species classified as endangered in Spain. A study compiled by Spanish researchers reveals - in a level of detail ...

Jewell orders firefighting strategy that protects habitat

Jan 06, 2015

Interior Secretary Sally Jewell is calling for a new wildfire-fighting strategy to protect a wide swath of sagebrush country in the intermountain West that supports cattle ranching and is home to a struggling bird species.

Recommended for you

'Tiger heavyweight' Nepal hosts anti-poaching summit

12 hours ago

Nepal's success in turning tiger-fearing villagers into their protectors has seen none of the endangered cats killed for almost three years, offering key lessons for an anti-poaching summit opening in Kathmandu ...

GMO mosquito plan sparks outcry in Florida

Jan 31, 2015

A British company's plan to unleash hordes of genetically modified mosquitoes in Florida to reduce the threat of dengue fever and other diseases has sparked an outcry from fearful residents.

Population genomics unveil seahorse domain

Jan 30, 2015

In a finding vital to effective species management, a team including City College of New York biologists has determined that the lined seahorse (Hippocampus erectus) is more a permanent resident of the we ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.