Influence of Predation on Rodent Populations

Predation on populations of small rodents is reviewed. Various types of predators are distinguished; specialists, generalists, residents, and nomadic species. Their functional and numerical responses to changes in prey density, and their influence on small rodent numbers, are discussed. The shape of the functional response curve of the predators may be important for the dynamics of the predator-prey system. Generalists with access to alternative prey tend to stabilize rodent numbers, as do migrating specialists, whereas resident specialists may be destabilizing. Field studies on cyclic rodent populations point to the importance of predation during and after the decline phase, and indicate that predation may increase the amplitude and prolong the period of the cycles. Other studies indicate a strong influence of predation on rodent numbers in areas with a diversified prey and predator fauna.