Large-scale land-use change across the tropics has led to the decline of animal populations and their habitat. With large investments into mining, hydropower dams and industrial agriculture this trend is likely to continue. Consequently, there is a need for systematic land-use planning to set aside areas for protection and allocate scarce conservation funding effectively. Even though primates are relatively well studied, data-driven systematic planning is still rarely implemented. The overall aim of this dissertation was to investigate population parameters needed for evidence-based conservation planning for the critically endangered western chimpanzee (Pan troglodytes verus) in West Africa. To this end, I compiled density datasets covering the entire geographic range of this taxon from the IUCN SSC A.P.E.S. database and modeled chimpanzee densities as a function of 20 social-ecological variables. I found that western chimpanzees seemingly persist within three social-ecological configurations: rainforests with a low degree of anthropogenic threats, steep areas that are less likely to be developed and are harder to access by humans, and areas with a high prevalence of cultural taboos against hunting chimpanzees. The third configuration of reduced hunting pressure is not yet reflected in commonly implemented conservation interventions, suggesting a need for designing new approaches aimed at reducing the threat of hunting. Based on the modeled density distribution, I estimated that 52,811 (95% CI 17,577-96,564) western chimpanzees remain in West Africa, and identified areas of high conservation value to which conservation interventions should be targeted. These results can be used to inform the expansion of the protected area network in West Africa, to quantify the impact of planned industrial projects on western chimpanzees, and to guide the systematic allocation of conservation funding. In addition, this thesis highlights the unique position of taxon-specific databases of providing access to high-resolution data at the scale needed for conservation planning. Data-driven conservation planning has the potential to enable conservationists to respond more proactively to current and emerging threats, and ultimately improve conservation outcomes