Williamson EA (2014) Mountain gorillas: a shifting demographic landscape. In: Yamagiwa J & Karczmarski L (eds.) Primates and Cetaceans: Field Research and Conservation of Complex Mammalian Societies. Primatology Monographs, 5. Tokyo: Springer Japan, pp. 273-287. http://link.springer.com/book/10.1007/978-4-431-54523-1
Large-scale habitat destruction and poaching in the 1950s, 1960s, and 1970s had major impacts on the population size and demography of mountain gorillas (Gorilla beringei beringei) in Rwanda. In those three decades, the population of the Virunga Volcanoes was halved: groups became unstable, and infanticide was relatively common. Intensive conservation efforts began in the 1980s and have enabled the gorilla population to recover. The present study took place during a period of social stability in the lives of three Karisoke gorilla groups. Characterized by few female transfers, no known infanticide, and only one silverback male departure from the research groups, there were striking increases in both group size and the number of adult males per group. I consider how these changes have occurred and implications for the management of this Critically Endangered primate. Despite encouraging growth, this population is so small that it remains extremely vulnerable to human disturbance. If mountain gorillas are to survive in this volatile region, a hands-on approach to their conservation may be justified.