Upstream from Khartoum, the Blue Nile flows through dry savannah. Then, on the fringe of the Ethiopian Highlands, the river emerges from deep inside a gorge, so steep and hostile that it has claimed the lives of many who've tried to explore the river further. But the bottom of this gorge shows little promise of a great flood. It's barren. This is a tough place to make a living. They're crossing the dried-out river bed of the Blue Nile. Right now it's no more than a trickle, just enough to warrant a trek of many hours to bring livestock to drink. But the huge boulders that cover the river bed suggest that at some time a powerful force of water must flow through here. The lammergeyer, Africa's mountain vulture, seeks out those who succumb to the heat and the drought. In this brutal season, the lammergeyer will have plenty to choose from.


喀土穆上游的青尼罗河流域是一片旱地稀树草原。随后，就在埃塞俄比亚高原的边际处，河水从幽深的峡谷中流出。这陡峭嶙峋的峡谷曾经夺走了许多试图上溯大河的冒险家的生命。但峡谷的底部却几乎没有泛滥流经的迹象。荒芜贫脊，这里是难以生存的不毛之地。这些人畜正在穿越现在只有一条涓涓细流的青尼罗河干涸河床。稀少的水量只能保证让跋涉了好几个小时的牧民们带来的牲畜有水可饮。但覆盖在河床上的漂砾暗示着曾几何时一定有强大激流流经此地。胡兀鹫，也被称作非洲高山兀鹫，在空中猎寻着不敌高热干旱的生物。在这种严酷时期，胡兀鹫有太多的选项可供选择。