Large‐Bodied and Wide‐Beaked Avian Frugivores Show Greater Specialisation in Tropical Seed Dispersal Networks

Aim Avian frugivores with large bodies and beaks are increasingly threatened due to smaller population sizes, greater energy requirements and higher vulnerability to hunting pressure and illegal wildlife trade. However, it remains unclear whether birds with these traits adopt consistent strategies in their interactions with fleshy‐fruited plants and, therefore, hold specific trait‐driven roles in fruit‐frugivore networks that are difficult to replace under extinction scenarios. Location Worldwide. Time Period Contemporary. Major Taxa Studied Birds. Methods Here, we analyse 215 avian frugivory networks spanning diverse bioregions, ecosystems and habitats to examine whether body mass and beak width influence the functional roles and position of avian frugivores in interaction networks. Specifically, we first examine how these traits relate to species‐level network metrics. In addition, we simulated the removal of species with extreme (i.e., higher and lower) body mass and beak width values to study whether relationships at the species level can scale up and affect overall network structure. Results Our findings indicate that larger species, as well as those with wider beaks, play more specialised roles in tropical frugivory networks (higher d ′), with wide‐beaked species having fewer interactions and larger species being involved in interactions of greater strength. The potential extinction of a few of these species with extreme traits could scale up, modifying network structure. The consistent pattern observed across different conditions suggests that large‐bodied frugivores, which in turn show stronger dependence on fruits, may have evolved to fill niche‐specific seed dispersal roles in highly diverse environments – roles whose functional singularity is difficult to replace. Main Conclusions These results emphasise the importance of implementing targeted conservation strategies to protect large‐bodied and large‐beaked avian frugivores. Such efforts are crucial for maintaining the integrity of seed dispersal networks and, consequently, supporting broader ecosystem functioning.