It would be nice to end the story on that note, but the narrative becomes less hopeful when one exits the parks to explore the larger Serengeti-Mara ecosystem, where the future of the region's wildlife and people is being written. This larger area, defined by the annual wanderings of the wildebeest herd, wraps around the Serengeti, sprawling over some 10,400 square miles (26,900 square kilometers)of Tanzania and southwestern Kenya, from the Crater Highlands and Great Rift Valley in the east, across the grassy plains and woodlands of the Serengeti interior, westward down a narrow corridor of hills and scattered woodlands leading to Lake Victoria, and finally northward across the Kenya border to the Masai Mara National Reserve, a small but critical haven where migrating animals find plentiful forage and water in the dry season.

Once sparsely settled and hospitable to the Serengeti's wildlife, the ecosystem has shrunk to half its former size, eroded in the 20th century by booming human populations in Tanzania and Kenya. In Tanzania, where the numbers have tripled to more than 36 million since the country won its independence in the early 1960s, Serengeti and Ngorongoro have become islands of wilderness washed by a rising sea of humanity, with people pressing right up against the patchwork of game reserves and conservation areas that buffer the protected core. Land is at a premium in this poor country of farmers, where less than 5 percent of the earth is cultivated and a quarter of the land is reserved for parks. Almost 40 percent of the populace lives below the poverty line.

Day and night, people steal into Serengeti to poach wood for building and cooking and to hunt resident and migratory wildlife in increasing numbers. Their proximity to the park brings native Tanzanians into constant conflict with wildlife.

"You see more farms, more livestock, more cotton and rice cultivation moving toward the park each year," said Justin Hando, chief warden for Serengeti National Park. "People who used to live 80 kilometers (50 miles) from the park now live five or six kilometers (three or four miles) away—so it's much easier for them to engage in illegal activity. The animals from the park try to do what they have always done—they cross back and forth over the boundaries. The difference now is that the free movement of animals is no longer possible," said Hando. "They have more interaction with people."