Performance of pollinators of the tropical bromeliad Tillandsia stricta Sol. (Bromeliaceae) in the Atlantic forest, Rio de Janeiro

Abstract

ABSTRACT Background Most bromeliad (Bromeliaceae) species have specialised flowers for specific pollinators, establishing a mutualistic relationship. However, other animals may also pollinate bromeliads, though it is logical to assume that specialised flowers are more compatible with one specific group of pollinators. Aims We compared the performance of a hummingbird (Thalurania glaucopis) and a butterfly (Heliconius erato) as pollinators of flowers classified as ornithophilous of the bromeliad Tillandsia stricta (Bromeliaceae). Methods We applied the single visit method with seed counting, and measured corolla tube length of flowers. We also conducted observations on plants to determine the effectiveness of pollination by the hummingbird and the butterfly. Results Both animal species pollinated flowers, although the hummingbird was a more frequent and effective pollinator, resulting in greater seed production. The corolla tube length of T. stricta was a significant predictor of seeds produced per flower following interactions with the hummingbird, but not with the butterfly. Conclusion Our results indicate a more intimate flower – pollinator relationship between T. stricta and the hummingbird than the butterfly in this population of the bromeliad in Rio de Janeiro, Brazil.