Cape Town wears the biodiversity crown

Cape Town is the most biodiverse urban area in the world.

The honour was bestowed by the leader of the UN's City and Biodiversity Outlook Project, Thomas Elmqvist, a Swedish expert in natural resource management and urban landscapes.

His assessment comes in an article published yesterday as part of The Guardian's Cities project, with writer Feike de Jong reporting: "The world's most biodiverse urban area, in raw numbers and with an understanding for its value, could be Cape Town."

De Jong said Western Cape was home to half of all South African's mammal species.

"Baboons, ostriches and zebras live in Table Mountain National Park. Whales, seals and otters swim off its shores.

"The stability of Cape Town's climate on the southern tip of Africa has enabled it to become home to approximately 3000 species of plants, 361 species of birds and 83 species of mammals."

But the city's biodiversity was under threat as its human population grew.

"Some 318 types of plants, 22 types of birds and 24 types of animals are in danger of extinction. But Cape Town is taking a variety of measures to protect and preserve this incredible natural asset."

De Jong's report, as part of a series funded by the Rockefeller Foundation, said calculating cities' biodiversity was complicated.

"Not all cities have the same area within their administrative limits, or the data necessary."

Cape Town's rivals for the title included Sao Paulo and Mexico City.

"Sao Paulo perches between Brazil's great Atlantic rainforest and the tropical savannah of the Cerrado - two highly rich biomes.

"Mexico City contains 2% of the world's species within its city limits," the report said.