O impacto de bebedouros na distribuição espacial e visitação de flores por beija-flores

Abstract

Artificial bird feeders, such as hummingbird feeders, are equipment used for recreational purposes and permitted by law in protected areas to attract birds and raise visitor awareness. However, this anthropogenic action can alter the natural environment and influence bird visitation behavior, such as flower visitation, and consequently affect the pollination process, an important ecosystem service. With diverging results on its effects in the literature, this study's main objectives are to quantify the influence of hummingbird feeders on the spatial distribution of hummingbirds and their behavior as flower visitors in a preserved area. Specifically, we evaluated the impact of the presence of these feeders on hummingbird visits to the inflorescences of Portea petropolitana (Bromeliaceae), a common species in the study area. We defined four 105m transects with observation points at every 35m in which we observed hummingbird visits to the inflorescences of P. petropolitana in the presence and absence of the feeders installed at the starting points of each transect. Our results revealed that, in both scenarios, there was a decrease in hummingbird visits along the transects. Although hummingbird visits to the feeders were more frequent than to the inflorescences at the starting point of each transect, there was no evidence that the feeders influenced the visiting behavior of these birds. Specifically, the presence of drinking fountains increased the diversity of hummingbirds without significantly affecting their spatial distribution or flower visitation pattern. This is because we detected no effects on the diversity of hummingbirds or the number of visits to P. petropolitana flowers located at least 35m from the feeders. Therefore, hummingbird feeders prove to be a viable option for environmental education and leisure activities at the study site.