LOS ANGELES – Some flowering plants draw helpful pollinating bats to their blooms by harnessing sound, scientists have found. A peculiar leaf on a Cuban rain forest vine produces an echo signature easily identified by the bats, according to a paper in the journal Science.

Plants often use striking colors and designs to draw bird and insect pollinators to their nectar. But bats feed at night and navigate primarily by sound, using the echoes from their high-pitched cries to maneuver through their environment.

Certain plants present their flowers on extended stems or produce petals that strongly reflect sound. Ralph Simon, a biologist at the University of Ulm in Germany, and colleagues tested whether nectar-feeding bats could find them faster.

Researchers used the vine Marcgravia evenia. Most of its leaves seem perfectly ordinary — except for the few strange, deep-bowled ones that stand upright over the vine’s flowers, a little like satellite dishes.

The scientists hypothesized that the curved shape of the leaf would strongly reflect sound hitting it from many different angles, which would make it easily recognizable to the bats.

To test this, the team hid a plastic feeder filled with sugar water in a room filled with fake foliage arranged to mimic a rain forest environment. It took captive bats 23.2 seconds on average to find the feeder when it was placed alone. When the feeder was attached to a replica of a normal-shaped vine leaf, the bats found it in 22 seconds.

But when the feeder was accompanied by a replica of the special, dish-shaped leaf of Marcgravia evenia, the bats took about half the time to locate it — 12.3 seconds — a key advantage, since the creatures often visit hundreds of flowers in just one night.