In late 2010, the Serengeti Lion Project extended its activities from the southeastern Serengeti and the floor of the Ngorongoro Crater to work on lion conservation in the Maasai inhabited parts of the Ngorongoro Conservation Area (NCA). These pastoralists are expected to co-exist with wildlife, but lions are persistent predators of Maasai cattle – and Maasai retaliate by killing lions. The human population in the NCA has increased from 8,000 in 1959 to 80,000 today, creating a formidable barrier for lions that might otherwise reach the Ngorongoro Crater from the Serengeti National Park. As a result the Crater lions have become increasingly isolated and inbred: the Crater population is only half its potential size (down to 50 individuals from over 100 in the 1980s) and shows higher susceptibility to disease and impaired reproduction.

Long term, a human-wildlife co-existence program in the NCA is the best hope for ensuring the vitality of the Crater lions. The Crater is world famous and receives significant earnings from wildlife-based tourism. Meanwhile there is currently no system to reduce livestock losses to the same predators that attract tourists in the first place. Thus the Maasai have little incentive to tolerate predators.