Bromeliads going batty: pollinator partitioning among sympatric chiropterophilous Bromeliaceae

Sympatric flowering species must frequently share pollinators. Pollinators can be a limited resource for the sexual reproduction of a plant, and such sharing could decrease individual reproductive success through the effects of different forms of competition. Many bromeliad species are sympatric and share pollinators. Bats are important pollinators of many Neotropical plants, including the Bromeliaceae; however, the pre-pollination mechanisms for isolation among sympatric bat-pollinated bromeliads are unknown.

Nectarivorous bat captured during this study
Nectarivorous bat captured during this study (left) and the bat species Anoura geoffroyi visiting the flower of the bromeliad Werauhia noctiflorens. Image credits: P.A. Aguilar Rodríguez and M.C. MacSwiney G.

A recent study by Aguilar-Rodríguez et al. published in AoBP investigated the mechanisms for reproductive segregation between four sympatric bromeliads in Veracruz, Mexico. With ex situ and in situ manual pollination treatments the authors determined breeding system by assessing fruiting and seedling success. They also sampled bat visitors using mist-nets and infrared cameras. Bromeliads showed staggered flowering, different pollen deposition sites on the body of the pollinator and differences in the reward offered. These traits may have evolved to reduce the competitive costs of sharing pollinators while providing a constant supply of food for the nectarivorous bat community.