The human footprint map prepared by the Wildlife Conservation Society (WCS) shows the impact of development on every square kilometer (about 0.4 square miles) of Africa. The reddest areas show the heaviest human footprint; the green areas show the lightest. Not surprisingly, the Sahara and other deserts are largely green.

Explorer-conservationist J. Michael (Mike) Fay superimposed this map on a separate map of Africa's ecosystems, prepared by the World Wildlife Fund, to calculate the wildest spot in each ecosystem.

The blue line on the map on this page shows the route Fay took to fly around Africa, moving from heavily settled areas to the places where there has been the least human impact.

The "Megaflyover" expedition, a joint project of WCS and National Geographic, gathered more than 100,000 digital images shot from only a few hundred feet (about one hundred meters) above the ground.

• Read the news story.

• Read an interview with Mike Fay.

• Watch Mike Fay's Megaflyover video.