Acoustic guide in bat-pollinated flower

Abstract

Several hundred species of neotropical plants are pollinated by glossophagine bats¹,². These bats use their highly developed sonar system for orientation, so we might expect bat-pollinated flowers to have evolved acoustically conspicuous structures to make them easier to detect. We find that the bat-pollinated neotropical vine Mucuna holtonii directs its echolocating pollinators to its flowers by means of an acoustic nectar guide. The flower contains a small concave ‘mirror’ that works like an optical cat's eye, but in the acoustic domain, reflecting most of the energy of the bats' echolocation calls back into the direction of incidence.