The analysis of the pollen load carried by Hummingbirds from Caatinga and Cerrado areas in Chapada Diamantina, Bahia, Brazil

This study dealt with the composition of pollen loads carried by hummingbirds in Caatinga and Cerrado areas, in the Chapada Diamantina, BA, Brazil. In each area, hummingbirds were captured with mist nets. Adhesive strips were used to collect pollen found on hummingbirds’ bodies. The pollen grains had been treated by acetolysis and analyzed and identified by light microscope. Six hummingbirds (4 spp.) were captured: five in the Caatinga area (one of Amazilia lactea and Chlorostilbon lucidus, and three specimens of Phaethornis pretrei) and only one in the Cerrado area (Heliactin bilophus). In total, 70 pollen types were observed in the pollen load carried by the hummingbirds. In the birds collected in Caatinga area, 65 pollen types were recognized and 27 had their botanical affinity established. The specimen captured in Cerrado area carried 32 pollen types (14 identified). In Caatinga, the species of Trochilinae had carried less pollen types – because of the territorialism behavior; they visit less species of plants, restricted to their territories. Phaethornis pretrei carried more pollen types. The strategy of trap-lining forage, typical of the Phaethornithinae, makes it possible to explore flowers of a bigger number of species. In the Cerrado, where there was little amount of resources (flowers), the great number of pollen types carried by Heliactin bilophus (Trochilinae) suggests that it had alteration of the standard of typical forage behavior of its sub-family (territorialism) and behaved as trap-liner. The analysis of the pollen flora carried by hummingbirds is a valuable tool for the determination of the composition of plants that these birds explore as well as for the understanding of the strategies of forage behavior of this group.