Serengeti National Park lies in northern Tanzania between Lake Victoria and the East African Rift Valley. It was established in 1929 (and expanded in 1940) to protect 5,600 square miles (14,500 sq. km) of the Serengeti plains ecosystem. This vast park spans an area twice the size of Yellowstone National Park and supports over 94 species of mammals, 400 species of birds, and includes the spectacular migration routes of the largest herds of grazing animals to be seen anywhere in the world.

Each year, migrating herds move clockwise around the Park, constantly seeking better feeding grounds. Changing water availability is the key factor in the annual migrations, which correlate closely with the local cycles of rainfall. At the right time of year, visitors to the Park can see hundreds of thousands of migrating herds of wildebeest (Connochates taurinus), running in winding lines several miles long. The wildebeest are accompanied by...