Dafa from: Consequences of forest degradation on vertebrate scavenger assemblages and functioning in a seasonally dry Neotropical forest

Forest degradation, a pervasive driver of biodiversity loss, affects not only species present in the ecosystem but also key ecological processes. Among them, vertebrate scavengers play a crucial role in nutrient cycling, organic matter decomposition, and disease regulation, yet remain poorly studied in Neotropical dry forests. We investigated how forest degradation influences scavenger assemblages and carrion removal in the seasonally dry tropical forests (SDTFs) of the Tumbesian region, a global hotspot of endemism and conservation concern. Using 60 chicken carcasses monitored with camera traps during the dry season (December 2021–February 2022) in southern Ecuador, we compared scavenging dynamics across three forest degradation states: Semi-natural forest, Shrub-dominated forest, and Arid land. We recorded 13 scavenger species (six mammals, six birds, one reptile), with estimated richness reaching 17 species. Semi-natural forests supported the highest richness and diversity (Shanon's and Simpson's indices), including species absent in degraded habitats such as the king vulture (Sarcoramphus papa), the great black hawk (Buteogallus urubitinga) and the white-tailed jay (Cyanocorax mystacalis). In contrast, more degraded habitats were dominated by generalists, particularly the Sechuran fox (Lycalopex sechurae), which accounted for nearly half of carcasses and significantly accelerated carrion removal (GLM, p = 0.02). Carcass persistence was shorter in degraded habitats (1.2–1.8 days) than in Semi-natural forests (3.8 days), reflecting dominance by opportunistic species. Our findings show that although carrion removal efficiency remained high in degraded habitats, this occurred at the expense of biodiversity and functional complexity. Semi-natural forests harbour richer and more diverse scavenger assemblages, which help stabilize food webs. This study provides the first empirical evidence that forest degradation alters vertebrate scavenger dynamics in the Tumbesian SDTFs, emphasizing that conserving well-preserved forests is crucial to maintain threatened vertebrates and ensure long-term food-web resilience.