# Non-Human Primates in Gabon: Occurrence Hotspots, Habitat Dynamics, Protected-Area Performance, and Conservation Challenges

## TL;DR

This study maps where primates in Gabon are most commonly found, how their habitats have changed over 30 years, and how well protected areas are working to conserve them.

## Contribution

The paper provides the first nationwide assessment of non-human primate conservation in Gabon, integrating habitat dynamics, species distribution, and protected-area effectiveness.

## Key findings

- Primate records are concentrated in the Ogooué-Ivindo and Haut-Ogooué regions, primarily in evergreen forests.
- Protected areas contain more primate records than expected, but some species remain mostly outside these areas.
- Agricultural conversion is the main driver of forest loss, despite overall forest stability from 1992 to 2022.

## Abstract

Gabon is home to many species of monkeys and apes, including gorillas and chimpanzees, but conservation decisions often lack a clear national picture of where these animals are most frequently recorded, how their habitats have changed, and how well protected areas are covering them. We combined wildlife records collected during field missions and from public biodiversity databases with national land-cover maps from 1992 and 2022 to identify where primate observations are concentrated to measure how forests and other land types have changed over 30 years and to test whether protected areas contain more primate records than would be expected by chance. We found that primate records were strongly concentrated in the Ogooué-Ivindo and Haut-Ogooué regions and were mostly located in evergreen forests. This forest type remained largely intact between 1992 and 2022, but most forest loss that did occur was linked to conversion to agriculture. Protected areas contained more primate records than expected, showing that they contribute to conservation, but some species such as the sun-tailed monkey were still mostly recorded outside protected areas. These results can help guide land-use planning by protecting key forest connections, strengthening conservation actions outside protected areas, and reducing habitat loss where farming is expanding.

Gabon harbors one of Africa’s richest assemblages of non-human primates (NHPs), yet integrated national-scale evidence on their conservation status remains limited. To inform conservation strategies, we conducted the first nationwide assessment integrating habitat dynamics, the geographic distribution of species, and the effectiveness of the protected-area network in the country. We harmonized 300 m land-cover maps (ESA CCI 1992; Copernicus 2022), compiled 481 georeferenced occurrences, and identified concentration areas using kernel density estimation and Getis–Ord Gi* analysis. We quantified land-cover transitions with a per-pixel transition matrix and assessed protected-area capture using Monte Carlo randomization. Ten fully protected species are confirmed, including Gorilla gorilla and Pan troglodytes. Occurrences concentrate mainly in the Ogooué-Ivindo and Haut-Ogooué Provinces; ~10% of the national territory lies above the 90th kernel density percentile (≈26,700 km2), and 1.5% of cells qualify as hotspots at the 99% threshold. Primate records are strongly associated with evergreen broadleaved forests (87.9% of points), which remained persistent from 1992 to 2022 (forest-to-forest = 223,476 km2; 98.13%) with a net decline (−2571.66 km2; −1.19%). Gross losses (4046.58 km2) were mainly attributable to agricultural conversion (68.63%; χ2 = 31,525; p < 0.001). Over 90% of records fall in areas stable across 1992–2022. Protected areas (PAs) captured more occurrences (observed 40.1% vs. expected 18.47%; p < 0.001), yet gaps remain for some taxa (e.g., Allochorocebus solatus, 86% outside PAs). Overall, Gabon retains an extensive core of suitable habitat, but targeted action outside PAs and maintenance of landscape connectivity are needed to secure populations where agricultural expansion and fragmentation are intensifying.