Interações entre beija-flores e plantas que visitam em uma área urbanizada do semiárido brasileiro

Abstract

Ecological interactions are fundamental for the maintenance of ecosystem services. Studies on the interactions between plant communities and hummingbirds have provided important insights into the evolutionary and ecological aspects of this relationship. However, research focusing on the effects of urbanization on the organization of nectarivore and plant communities remains scarce. Weekly expeditions were conducted on the campus of the State University of Feira de Santana, Bahia, between 2018 and 2023. Using the focal-individual method, visiting hummingbird species, types of visits, and their foraging strategies were recorded. The phenological patterns of flowering for each species and the plant community visited were estimated, and the seasonal patterns of hummingbirds were classified. To estimate the seasonal pattern of visited plants, biweekly censuses of flowering species were conducted in a 3200 m² area. Between 2018 and 2023, 5,799 visits by hummingbirds were recorded. Thirty-seven plant species were visited by four hummingbird species, with two considered residents. The plant species with the highest relative visitation frequency was Sanchezia nobilis. Among the recorded plants, 54% are ornithophilous. A total of 439 agonistic interactions among hummingbirds were observed, with approximately 81.6% being intraspecific. E. macroura was identified as a keystone species throughout all periods. Three mutualistic interaction networks were developed: the first is a general network, the second relates to the dry season, and the third is associated with the rainy season. The investigation of mutualistic interaction networks on the UEFS campus demonstrates that the richness and connectivity of the networks are strongly influenced by climatic conditions, with the dry-season network showing greater richness and connectance.