Mimi Arandjelovic, Josephine Head, Luisa I. Rabanal, Grit Schubert, Elisabeth Mettke, Christophe Boesch, Martha M. Robbins, Linda Vigilant

An assessment of population size and structure is an important first step in devising conservation and management plans for endangered species. Many threatened animals are elusive, rare and live in habitats that prohibit directly counting individuals. For example, a well-founded estimate of the number of great apes currently living in the wild is lacking. Developing methods to obtain accurate population estimates for these species is a priority for their conservation management. Genotyping non-invasively collected faecal samples is an effective way of evaluating a species' population size without disruption, and can also reveal details concerning population structure.