Form Feeds Function

Nectar bats make several hundred flower visits nightly to fuel their roaring metabolism. In the tropical forests of Central and South America, plants have found unique ways to attract bats. The flowers of these plants shape the echoes of bats’ calls, providing sound cues that streamline foraging—a strategy that pays off in improved pollination for the plant.

Leaf Shape

Marcgravia evenia’s dish-like leaves return conspicuous echoes from longer distances and across wider angles.

A cross section of the leaf shows sound reflecting back to the bat.

Isolation From Foliage

Mucuna holtonii dangles accessibly below the forest canopy. Echoes from a concave petal on each bloom convey precise cues.

Once a bat has fed at one of its flowers, Mucuna holtonii’s echo changes, signaling hungry bats to look elsewhere for a meal.

Sound Dampening

Espostoa frutescens brightens its flowers’ echoes by muffling the background with a strip of sound-absorbent “fur.”

The echo differs if a flower has bloomed on Espostoa frutescens.

Sound Enhancing

Blooming on the stem (cauliflory) and waxy petals help Crescentia cujete stand out acoustically.

Matthew Twombly, NGM Staff; Mesa Schumacher. Sources: Ralph Simon, Department of Sensor Technology, University of Erlangen; Merlin D. Tuttle, Department of Integrative Biology, University of Texas; Nathan Muchhala, University of Missouri-St. Louis