Savanna ecosystems such as the Serengeti in Africa are areas of diverse wildlife that depend upon limited water supplies to survive from one rainy season to the next. Global warming, however, threatens the availabiity of the limited year-long water supplies necessary to support wildlife. Meanwhile, another threat to the wildlife of the savannas is increased poaching and killing of wildlife by settlements on the edge of national park and wildlife preserve. All of these threaten the very survival of such animals as the African lion, elephants etc.