Underrated Links Mitigate the Fragmentation-Induced Mutualism Breakdown in a Large-Fruited Species

Seed dispersal is threatened in fragmented landscapes by the loss of frugivores, significantly undermining the persistence of large-fruited plant species that rely on large-bodied animals. However, we lack a quantitative understanding of the roles of small-bodied frugivores in seed dispersal through fruit transportation. In an insular fragmented landscape formed by dam construction in 1959, we employed camera traps to document frugivory of a large-fruited plant species (Diospyros kaki) by camera trapping at both ground and arboreal levels. Our results reveal that reduced habitat size led to mutualism breakdown of seed dispersal of D. kaki mediated by large-bodied mammalian frugivores compared to the nearby mainland sites. However, underrated links involving fruit transportation by small-bodied frugivores, often present yet overlooked dispersal processes, may help mitigate these interaction losses. These findings highlight the importance of preserving large, continuous habitats and underrated mutualistic links in sustaining seed dispersal of large-fruited plants in fragmented landscapes.