In 1970 two Germans set out on a gruelling three-month trek across the Moroccan Sahara. This is not the Sahara of sand dunes and oases, but the stone desert where rocks reach temperatures of 140 degrees in the day and almost freeze at night, where plants have to survive for four years without water. It's hard to believe that anything survives there but it does. There are reptiles that can burrow through sand like a fish through water, birds that build their own air conditioning into their nests, grouse that can carry enough water over long distances in their plumage for their chicks to feed on, snakes that have developed a special movement to avoid being roasted alive.
Tonight's Horizon is a record of ornithologist Uwe George's journey and of the remarkable wildlife he and his companion found.