Arboreal and Terrestrial Frugivore Vertebrate Assemblage Diversity and Composition Vary With Disturbance Histories in Guianan Forests

ABSTRACT

Frugivorous vertebrates, as seed dispersers and predators, play critical roles in forest ecosystem dynamics. Understanding their responses to human disturbances is essential for assessing ecosystem functioning and guiding conservation programs. Using 60 camera traps at nutmeg trees ( Virola kwatae and V. michelii , Myristicaceae), we monitored terrestrial and arboreal frugivores across three forest sites in French Guiana submitted to various human disturbances: a protected mature forest (least disturbed), a formerly exploited forest (intermediately disturbed), and a forest near a road subject to current hunting and logging (most disturbed). We assessed diversity, taxonomic composition and assemblage structure, while comparing visitation rates among sites. Richness remained consistent across all sites, with 19–20 species detected in the canopy and 14–16 in the understory. However, visitation rates significantly varied among sites. Specifically, terrestrial visitation rates decreased as disturbance levels increased (from 232.5 ± 53.7 individuals/100 trap‐days at the protected site to 87.2 ± 11.2 at the most disturbed site). Conversely, arboreal visitation rates tended to increase with increasing disturbances (from 43.5 ± 12.5 at the protected site to 80.3 ± 16 at the most disturbed site). In the canopy, the most disturbed site showed higher visits of kinkajous ( Potos flavus ) and golden‐handed tamarins ( Saguinus midas ). The understory at this same site had significantly lower visitation rates of “sensitive” species (those with low reproductive rates or targeted by hunters), such as white‐lipped peccaries ( Tayassu pecari ) and gray‐winged trumpeters ( Psophia crepitans ). In the canopy, site identity, tree diameter, fruit availability and canopy cover were significant predictors of assemblage composition. By contrast, none of the measured micro‐habitat variables contributed to the structure of the terrestrial assemblage, site identity being the single significant predictor. These findings underscore the importance of considering species‐specific responses and site disturbance histories, and highlight the value of protected and restoration areas in maintaining functional assemblages in tropical forests.