Modelling a Suitable Habitat for Nigeria–Cameroon Chimpanzees (Pan troglodytes ellioti, (…)

ABSTRACT

Tropical forest mammalian communities, particularly those in ecological transition zones, are under constant threat from human activity. In many regions, there is a lack of baseline data on suitable habitats and the environmental factors influencing their suitability. Habitat suitability is a key metric for guiding conservation decisions and is essential for adaptive management of wildlife. These threats mostly affect great apes, including critically endangered Nigeria–Cameroon chimpanzees (Pan troglodytes ellioti Matschie, 1914), which is losing much of the suitable habitat required for reproduction and survival across its distribution range, including Central Cameroon. However, little is known about the habitat suitability of this species, particularly those who inhabit the Mpem and Djim National Parks in Central Cameroon. To address this knowledge gap, we used a common species distribution model (MaxEnt) to map and predict suitable habitats based on environmental factors that potentially affect habitat suitability. These environmental factors were related to a dataset of chimpanzee occurrence points recorded during line transect, camera trapping, and reconnaissance surveys (reccee) in the park. After covering an area of approximately 558.671 km² on 160.78 km, we found that up to 60% of the study area is unsuitable for chimpanzees. Only 20% of the study area was highly suitable for chimpanzees. Our results also showed that chimpanzees prefer the central and western parts of the study area, which are characterized mainly by high forest density. The MaxEnt model performed well (mean AUC = 0.859 ± 0.086) and identified a clear spatial pattern of suitable habitats. The most important predictors that positively affect habitat suitability for the Nigeria–Cameroon chimpanzee were NDVI (36.7%), canopy height (17.2%), annual mean temperature (16.3%), forest density (4.2%), distance to road (4.2%), and terrain aspect (3.2%). The suitability map identifies areas that are particularly important for conservation management, especially in the central and western parts of the park. Our study provides robust evidence that certain parts of Mpem and Djim National Park remain suitable habitats for chimpanzees. However, much more effort is needed from the government, park managers, national and international policymakers, and local communities to maintain these habitats and prevent severe damage to the survival of this species in the area. While this study provides a robust baseline for the conservation planning and management of chimpanzees in the area, it also fills an existing gap in the scientific literature on the ecology of Nigeria–Cameroon chimpanzee communities in Central Cameroon. Furthermore, it highlights the need for large-scale surveys in the future to evaluate the impact of efforts implemented thus far on the habitat suitability of this species.