Diversidade beta de plantas que oferecem néctar como recurso floral aos beija-flores em cerrados do Brasil Central

Abstract

The open savanna areas of the Cerrado region in Central Brazil have been considered as marginal or complementary habitats for hummingbirds, despite the considerable number of hummingbirds recorded. These birds use a variety of plants without ornithophilous caracteristcs. The objective of the study was to investigate the flora used by hummingbirds as food resource in three Cerrado areas 20 to 150 km apart. In each of these cerrado s.s. areas, two transects of 1 ha each were walked fortnightly to identify the plant species used by hummingbirds, which were also identified. The number of plant species recorded (26) was higher than that observed for other studies in the same region but was lower than that recorded for forest habitats. Only nine plants (34%) showed a truly ornithophilous syndrome. There were nine hummingbird species (Trochilidae) in the three areas. Although the Cerrado flora has been characterized by its high ß-diversity, the hummingbird plants among transects and areas were very similar. Despite being truly ornithophilous or not, there were plants offering nectar to hummingbirds year round. The indiscriminate use of non-ornithophilous species corroborates the idea that, in Cerrado habitats, nectariferous plants seem to be more important to hummingbirds than vice-versa.