Structural stability of plant–pollinator interactions despite seasonal abundance of long‐tongued hawkmoths

Seasonal environmental cycles affect plant–pollinator interactions by altering plant phenology. Periods of low resource availability can filter pollinators and reduce the complexity of interaction networks, but the extent to which the functional morphology of pollinators influences such filtering remains unclear. Understanding these mechanisms is especially important in the context of global change, which may disrupt temporal plant–pollinator dynamics. We explored how seasonality affects the persistence and functional traits (proboscis length) of tropical hawkmoths and the structure and robustness of their pollen transfer network. We observed a consistent decrease in the diversity of hawkmoths in the dry season, particularly larger, long‐tongued species that were not persistent across all years, resulting in smaller interaction networks despite peaks in flowering activity. Although the mean proboscis length decreased in the dry season, structural parameters such as low specialization, modularity, and nestedness remained stable. The functional morphology–specialization relationships in the network (lower specialization of long‐tongued moths, and higher specialization for long‐tubed flowers) were also similar between seasons. These patterns imply that moth generalism and network linkage rules remain constant throughout the year, which is further suggested by the similarity of moth–flower morphological mismatches between seasons. Our findings suggest that the role of hawkmoths' functional morphology in network assembly does not change in a seasonal environment. Still, it is a significant variable that defines hawkmoth persistence, likely due to factors beyond proboscis–flower coupling (e.g. larval resource limitation, which affects larger species with proportionally longer proboscises). The prolonged absence of long‐tongued moths may negatively impact the pollination of specialized sphingophilous plants, highlighting the consequences that persistent and longer droughts related to global change may have on mutualistic interactions in highly seasonal ecosystems.