In this video, ecologist Tony Sinclair takes us through the steps of how he uncovered that the eradication of an infectious disease in cattle led to a boom in the Serengeti’s buffalo and wildebeest numbers.

When Sinclair arrived in the Serengeti in the 1960s, he was faced with a mystery: why were buffalo and wildebeest population sizes increasing so rapidly? Sinclair considered the two most likely answers: that these animals now had more food or fewer predators. However, the evidence did not support either explanation. Sinclair then discovered that scientists in the early 1960s had developed a vaccine against a virus called rinderpest. Rinderpest infected domesticated cattle, as well as wild buffalo and wildebeest. By examining skulls and blood samples from both buffalo and wildebeest, Sinclair showed that the disappearance of the virus from these animals precisely coincided with their increases in population sizes.

An audio descriptive version of the film is available via our media player.