In a new study, researchers have found that a Cuban rainforest vine has evolved dish-shaped leaves to help attract the bats which pollinate the plant. According to Discover magazine, the Marcgravia evenia plant has special leaves that reflect the sound waves emitted by bats more efficiently than a normal leaf. For the bats, which navigate by sound, these leaves are more prominent than the surrounding foliage, and draw the bats in to the vine's nectar cups. In other words, the vine "talks back" to bats.
BBC reports that a team of researchers in the U.K. and Germany “brought the plant into their laboratory and bounced to measure its acoustics - essentially firing sound pulses at it to see how they echoed.” They then used both the plant's dish-shaped and regular leaves to determine how long it took bats to locate a feeder in a dark room.
The results, published last week in Science, confirmed the researchers' predictions. National Geographic reports, “bats found a hidden feeder about 50 percent faster when the feeder was accompanied by the specialized M. evenia leaf than without. Attaching a regular leaf reduced bat search times by just 6 percent.”
Even though hundreds of plant species rely on bats for pollination, this is the first time scientists have discovered a plant with features that have evolved to facilitate echolocation. According to Ars Technica, there are bats in Europe, Africa and Asia which also pollinate flowers, but find the nectar with their eyes instead.
Other plant species that rely on pollinators with stronger vision have evolved brightly colored flowers to help attract insects or birds, reports Discover. For a bat, however, the M. evenia leaves “must be the aural equivalent of the Mona Lisa’s eyes, a burst of echoes that follow it wherever it goes.”
According to the Newsy video below, the leaves benefit both the plant, which is pollinated more easily, and the bats, which are able to find and consume more nectar each night.