Lions rarely hunt baboons. These large monkeys are armed with dangerous teeth, they are hard to catch and usually not worth the risk or effort. But there is one place in Africa\'s Great Rift Valley where baboons are plentiful and lions have learned to catch them. The river in Tarangire National Park in Tanzania never runs dry. During the dry season herds of animals come to the river to drink. It is a time of plenty for predators but when it rains on the surrounding plains, the herds abandon Tarangire. Then the predators have only the resident animals to hunt. Desperation forces the lions to target the large troops of baboons that sleep well out of reach of hungry cats but, during the heat of the day, are vulnerable to attack. To survive at ground level, the baboons join forces with their neighbours, including impala and banded mongooses, so there are many eyes on the look out for danger. But as hunger sharpens the senses, the predators learn how to ambush the baboons. As the land dries out, the herds wander back to the river and the time of hardship will be over for the lions. The pressure is off the baboons but with the monkey hunters about, they must always be vigilant.