The 45 years of data on small mammal diversity and abundance collected in the greater Serengeti ecosystem document 37 species in a range of habitats from forest to semi-desert.We have recorded fluctuations in rodent abundance from 1968 to 2010 and demonstrated that outbreaks in rodent abundance occur in natural ecosystems in Africa,not just in agricultural systems.Short-season rainfall is a major driver of rodent outbreaks and in turn small mammals play a vital role in the food web of the greater Serengeti ecosystem because several species of predators show a strong response to rodent abundance.It is likely that the influence of small mammals extends to other effects on trophic interactions and ecosystem function.For example,the numerical responses of predators to small mammals may indirectly impact other trophic levels such as invertebrates,amphibians and reptiles.Our 45-year time series demonstrates the value of long-term ecological data as a vital baseline from which to predict the impact of 1) future climate changes on the Serengeti ecosystem and 2) the impact of humans on agricultural landscapes.This research highlights the role of small mammals in maintaining the diversity and driving the population dynamics of a wide range of avian and mammalian predators.