Choosing appropriate management strategies and effective conservation actions requires information about the future consequences of current conservation actions; however, this crucial information is rarely available to conservation planners. This study applies scenario planning and agent-based modelling (ABM) to assess the potential impact of alternative management strategies on future suitability and functional connectivity of Cross River gorilla (CRG) habitat in the Nigeria–Cameroon border region. The CRG population is small and fragmented, with many subpopulations and migration corridors located outside protected areas. This study used ABM to simulate human land use in the study area over a period of 15 years under different management scenarios and assessed the impact on future suitability and functional connectivity of CRG habitat. The simulations showed that a landscape approach with greater focus on interventions to change human behaviour towards conserving gorillas and sustainable forest use would result in greater improvement in habitat suitability and functional connectivity compared to focusing on improving law enforcement within existing protected areas. However, the best scenarios were when both law enforcement and behaviour change increased. The results highlight the importance of human behaviour change to conservation in human-dominated landscapes and can inform conservation planning and management of other species and in similar landscapes.

Habitat loss and fragmentation are among the major threats to wildlife populations in tropical forests. Loss of habitat reduces the carrying capacity of the landscape and fragmentation disrupts biological processes and exposes wildlife populations to the effects of small population size, such as reduction of genetic diversity and increased impact of demographic stochasticity. The Critically Endangered Cross River gorilla Gorilla gorilla diehli is threatened in particular by habitat disturbance because its population is small and it lives in an area where high human population density results in intense exploitation of natural resources. We used remotely-sensed data to assess the extent and distribution of gorilla habitat in the Cross River region and delineated potential dispersal corridors. Our analysis revealed > 8,000 km2 of tropical forest in the study region, 2,500 km2 of which is in or adjacent to areas occupied by gorillas. We surveyed 12 areas of forest identified as potential gorilla habitat, 10 of which yielded new records of gorillas. The new records expand the known range of the Cross River gorilla by > 50%, and support genetic analyses that suggest greater connectivity of the population than previously assumed. These findings demonstrate that considerable connected forest habitat remains and that the area could potentially support a much larger gorilla population if anthropogenic pressures such as hunting could be reduced.