Though 99.9999% of species that have gone extinct have never actually been identified, it is common to read claims that we are facing a catastrophic species extinction crisis.

It's best to take such talk with a grain of salt, because conservationists are only now discovering that cities are better at preserving species than pristine wilderness environments. A recent study looked at the distributions of 1,643 protected species in Australia, and counted up the number of these species that occurred in square-kilometer units across the continent. They found that, on average, urban environments contain more threatened protected species in a given area than rural environments.

All cities in Australia contained protected species, and 30% of the species listed as protected in Australia inhabited urban environments. Cities consistently supported a greater number of protected species than other areas.

The findings highlight the opportunities that cities present for tackling biodiversity loss.

"Our results show that to tackle species extinction we can no longer afford to ignore the places where most of us live and work," said Dr. Christopher Ives, co-lead author of the Global Ecology and Biogeography study. "In Australia, every city has a role to play in safeguarding the country's most threatened biodiversity."