East African savannas have fascinated generations of explorers, scientists, and the public. Nowhere else is there such a concentration and diversity of large, charismatic animals, and nowhere else is ecology portrayed so dramatically. Spectacular migrations of a million wildebeest tracking the rains dominate the Serengeti-Mara ecosystem of Tanzania and Kenya. Lions and hyenas pursue gazelle, zebra, and buffalo in a conspicuous contest between predator and prey. And giraffe and elephants shape the landscape by browsing and trampling savanna trees.
The abundance of so many large mammals in East Africa has led to the assumption that interactions among these prominent animals dominate the ecological dynamics of the savanna communities. Recent research, however, has shown that there is also a cryptic web of interactions hidden in the tall savanna grasses. This web is centered around a group of herbivorous mammals that share both habitat and forage with their much larger hooved counterparts. These are the small mammals, and until recently almost nothing was known about their importance in savannas of East Africa.