Conservationists say they have discovered what could be one of the largest migrations of land mammals on Earth in southern Sudan.
The Wildlife Conservation Society (WCS) says more than 1.3 million antelope, gazelle, elephants and other animals - thought to have been wiped out by a long civil war in the region - were found.
The WCS's Michael Fay said he had never seen wildlife in such numbers - "not even while flying over the mass migrations of the Serengeti" park in Tanzania.
But in several areas there has been a dramatic decline of some key species, including buffalo and elephants, the WCS says.
The aerial survey was conducted in January - the WCS's first assessment of wildlife in the region since 1982. Pictures: Paul Elkan and J. Michael Fay.
COLLECTION OF WORLD'S BEST WALLPAPERS
WOW WHAT A BEAUTY
NATURE OF GOD
JAZZ OF LIFE
COOL PHOTOS BANK
BEAUTY OF WILDLIFE
BEST PHOTOS OF THE WORLD