Fire frequency drives structural changes in bat-mediated seed dispersal networks in Neotropical dry forests

Fire is a major driver of biodiversity change, influencing ecosystem composition, structure, and function. In Colombian tropical dry forests (TDF), however, its effects on ecological interactions remain largely unknown. We evaluated the effects of fire frequency changes over the structure of bat-mediated seed dispersal networks by analyzing connectance, specialization, modularity, and nestedness across three sites with contrasting fire histories. Connectance increased from 0.38 in unburned forests to 0.52 in high-frequency fire sites, while network specialization (H2′) decreased from 0.41 to 0.29 and modularity declined from 0.48 to 0.33, indicating a shift toward more generalized and less compartmentalized networks. Conversely, nestedness rose from 0.56 to 0.71, suggesting greater overlap in interactions among species. These structural shifts appear to be driven by the proliferation of super-generalist species, particularly Carollia perspicillata and Piper marginatum, which assumed central roles as connections from other species declined. Such dynamics highlight a trade-off between robustness and vulnerability: while generalist species sustain key ecosystem services under recurrent disturbance, the dependence on a few central taxa may increase long-term instability. To our knowledge, this is the first study to examine the effects of fire frequency on bat-mediated seed dispersal networks, offering novel perspectives on species resilience and the ecological functioning of fire-affected ecosystems.