Predation is one of the most important controls on the abundance of wildlife. Key to understanding how predators regulate the abundance of their prey and maintain their own numbers is knowing how predators change their behavior according to the prey they encounter. For example, predators might largely ignore rare types of prey and so help conserve them, simply consume all types of prey in proportion to their abundance, or reach an upper limit of consumption of very abundant prey, leaving them relatively free to multiply and dominate further. This project will refine our understanding of how predators respond to the abundance of prey by asking how responses differ between male and female predators and how threats from larger predators may change the behavior of smaller ones. In most cases, these questions are nearly impossible to answer directly because it is too hard to observe individual hunts in the wild, or because humans have exterminated predators. This project will take advance of a case where the researchers have developed methods to follow wild hunts in a largely intact system, predation by cheetahs on gazelles in the African savanna. The results of this project will expand the scientific basis for wildlife management in Africa and North America, improve conservation through outreach to the public, strengthen international collaboration, and train a U.S. Ph.D. student.
Functional responses of predators determine how the abundances of both predators and prey increase and decrease in nature. This project will deepen our understanding of rates and efficiencies of predation in nature by studying differences within a species of predator, in particular the potential for different responses in males and females to the density of prey that they encounter and to threats from larger predators as they hunt. The project will take advantage of a system where it is possible to follow individual predators in a habitat where large populations of wildlife still remain, cheetahs preying on gazelles in the savanna of Serengeti National Park in Tanzania. Researchers will watch hunts by individual cheetahs for several days each and combine these observations with historical data to discover how age of cheetahs, social grouping of cheetahs and gazelles, and threats from lions determine the rates at which female and male cheetahs kill prey. The project will use social media to educate the public about cheetahs, which are listed as a vulnerable species on the IUCN Red List. Researchers will deliver talks on conservation of wildlife to tour groups, safari drivers, and college students.