Infectious diseases can substantially reduce the size of wildlife populations, thereby affecting both the dynamics of ecosystems and biodiversity. Predicting the long-term consequences of epidemics is thus essential for conservation. Researchers from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in Berlin and from the Center for Functional Ecology and Evolution (CEFE) in Montpellier, France, have now developed a mathematical model (“matrix model”) to determine the impact of a major epidemic of canine distemper virus (CDV) on the population of spotted hyenas in the Serengeti National Park in Tanzania. The results of the study are published in the new Nature open-access journal Communications Biology.