This chapter compares the potential impacts of seasonal food abundance and predation risks on herbivore populations. It describes how herbivore species differ in their response to seasonal rainfall variation. Major droughts can induce severe population crashes. Abundant water accentuates local food depletion. Food shortages may cause animals to incur greater exposure to predation so that bottom-up and top-down influences are entangled. Demographic shifts may lower prey vulnerability to population growth rates, dependent on body size, and sustainable recruitment thresholds. Savanna ungulates differ in the breadth and seasonal timing of birth seasons. Medium–large grazing ruminants produce the most biomass annually. Browsers and equids are consistently less abundant than grazers, while smaller herbivores are more narrowly distributed regionally. Populations also expand and contract in their distribution.

This chapter describes how most large carnivores shift facultatively between hunting and scavenging. Stalking and coursing hunters differ in how strongly they select for weakened prey. Lions are dominant and their impact on prey demography affects food availability for other carnivores. Prey species selection by lions varies seasonally and annually depending on how rainfall affects prey vulnerability. Only Africa retains a full suite of stalking, coursing and scavenging carnivores.