Mammal Responses to Habitat Degradation Induced by Cashew Expansion in West Africa

Tropical landscapes are perishing due to high rates of land‐use change. In West Africa, Guinea‐Bissau has lost 77% of its closed‐canopy forest over the last 25 years mostly due to the expansion of cashew monoculture. To date, understanding how species cope with such changes remains a conservation priority for the region. Here, we examine mammal species composition, richness and photographic rate, in addition to trophic‐guild photographic rate across closed‐canopy sub‐humid forests and cashew orchards in the Cantanhez National Park, southwest Guinea‐Bissau. Mammals were surveyed using one camera trap at each of the 24 sites, half of which were located in forest and half in cashew orchards, with their local and landscape‐scale variables measured. Based on 709 trap‐nights, we collected 842 records of 25 mammal species. Local habitat structure—including canopy openness, floor obstruction, density of lianas, palms, and trees, tree species richness, and height—sharply contrasted between forests and cashew orchards. As expected, mammal species composition differed between forests and cashew orchards. Although species richness and overall mammal photographic rate remained unaffected by the variables considered, photographic rate for carnivores was higher in cashew‐like habitats, whereas that of insectivores and herbivores was higher in forest‐like habitats. Human activity and distance to forest did not affect the response variables considered. Our results indicate that forest conversion into cashew orchards can have negative and positive effects on specific mammal guilds by profoundly changing the local habitat structure. The different guild‐level responses unveiled specificity in their vulnerability to this form of land‐use change, alerting to a potential disruption in ecosystem functioning. We emphasize the need for policies that limit monoculture expansion while safeguarding the remaining forests, thus maximizing biodiversity persistence across the Afrotropics.