Temporal variation in fungal communities associated with tropical hummingbirds and nectarivorous bats

Species of yeasts and other microfungi carried by pollinators are of general ecological interest because some of these microbial species can grow in floral nectar and affect plant–pollinator interactions. It is, however, not well understood how the composition of fungal species found on pollinators varies over space or time. The spatial and temporal distribution patterns in the microfungi found on the bills of hummingbirds and in the mouths of nectarivorous bats was investigated along a gradient of deforestation within a Costa Rican countryside landscape. The community composition of microfungi found on hummingbirds' bills and bats' mouths underwent substantial compositional turnover over a 2-month period and between 2 yr. In contrast, fungal community composition was not significantly correlated with spatial distance, habitat type, species of hummingbirds, nor the forest dependency of the hummingbirds sampled for microfungi. These findings suggest that, in this landscape, fungal communities on a nectarivous vertebrate vector might be influenced primarily by temporal factors such as plant and flower phenology rather than spatial environmental heterogeneity.