In the temperate forests of Chile and Argentina, many plants are pollinated by the hummingbird Sephanoides sephaniodes. One such plant is the vine Campsidium valdivianum. In Argentina, the native bumblebee Bombus dahlbomii robs nectar from C. valdivianum flowers, showing a preference for those with longer corollas. In Chile, C. valdivianum flowers exhibit both small and large perforations, suggesting a greater diversity of nectar robbers. In the study area, nectar robbery could be attributed to native and exotic bumblebees (B. dahlbomii and Bombus terrestris), which are likely responsible for the small perforations, whereas native birds (Phrygilus patagonicus and Elaenia albiceps) are probably responsible for the large perforations. We hypothesized that plants with longer and narrower flowers would experience higher levels of nectar robbery, by both bumblebees and birds, compared to thos...