Global map shows new patterns of extin...( Professor Owens adds that this geogr...)

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.