Rainforest plant developed sonar dish to attract pollinating bats

Jul 28, 2011

The researchers discovered that a rainforest vine, pollinated by bats, has evolved dish-shaped leaves with such conspicuous echoes that nectar-feeding bats can find its flowers twice as fast by echolocation. The study is published today in Science.

While it is well known that the bright colours of flowers serve to attract visually-guided pollinators such as bees and birds, little research has been done to see whether plants which rely on echolocating for and have evolved analogous echo-acoustic signals.

The Cuban rainforest vine Marcgravia evenia has developed a distinctively shaped concave leaf next to its flowers which, the researchers noticed, is reminiscent of a dish . By analyzing the leaf's acoustic reflection properties, they found that it acts as an ideal echo beacon, sending back strong, multidirectional with an easily recognizable, and unvarying acoustic signature – perfect for making the flower obvious to echolocating bats.

They then trained nectar-feeding bats (Glossophaga soricina) to search for a single small feeder hidden within an artificial foliage background, varying the feeder's position and measuring the time the bats took to find it. The feeder was presented on its own or with a replica of either a foliage leaf or the distinctive dish-shaped leaf. Each feeder type was randomly tested once at each of the 64 positions within the artificial foliage background.

Search times were longest for all bats when the feeder was presented on its own and were slightly, but not significantly, shorter when a replica of a foliage leaf was added. However, a dish-shaped leaf replica above the feeder always reduced search times – by around 50 per cent.

Although the leaf's unusual shape and orientation reduce its photosynthetic yield compared to a similarly sized foliage leaf, the researchers argue that these costs are outweighed by the benefits of more efficient pollinator attraction.

Dr Marc Holderied of Bristol's School of Biological Sciences, co-author of the paper, said: "This echo beacon has benefits for both the plant and the bats. On one hand, it increases the foraging efficiency of nectar-feeding bats, which is of particular importance as they have to pay hundreds of visits to flowers each night to fulfill their energy needs. On the other hand, the M. evenia occurs in such low abundance that it requires highly mobile pollinators."

Bats, with their wide home range and excellent spatial memory, are exceptionally efficient pollinators and many other neotropical plants depend on them for pollination. As the acoustic and perceptual principles shaping the echo beacon leaf of Marcgravia evenia should work for all echolocating pollinators, the researchers expect to find other instances of plant species that use acoustic signalling to attract their bat pollinators.

Explore further: Narwhal tusk length linked to testes mass suggesting its purpose is for attracting females

Related Stories

How to share a bat

Aug 22, 2007

New research shows how different species of plants evolve unique floral adaptations in order to transfer pollen on different regions of bats’ bodies, thus allowing multiple plant species to share bats as pollinators.

Drunk Bats Manage To Pass Sobriety Tests

Feb 18, 2010

(PhysOrg.com) -- New World Leaf-nosed bats (Chiroptera Phyllostomidae) are thriving in the tropical forests of Central and South America, even though their diets consist of more fruits and nectars than their ...

Bats' echolocation recorded for human exploit

May 11, 2010

Bats' remarkable ability to 'see' in the dark uses the echoes from their own calls to decipher the shape of their dark surroundings. This process, known as echolocation, allows bats to perceive their surroundings ...

Why nectar-feeding bats need a 'power drink' to fly

Aug 07, 2007

Nectar-feeding bats burn sugar faster than any other mammal on Earth – and three times faster than even top-class athletes – ecologists have discovered. The findings, published online in the British Ecological Society's ...

Recommended for you

New hope for beloved family pets

9 hours ago

Nearly one out of four dogs will develop cancer in their lifetime and 20 per cent of those will be lymphoma cases.

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

FunkyDude
1 / 5 (1) Jul 28, 2011
or.. the plants that had sonar shaped dishes were more likely to survive than those that did not
Y8Q412VBZP21010
not rated yet Jul 28, 2011
Dis un's almost as much fun as the pitcher plants adapted as bat bunks ... give it a fiver, I'll have to comment on it in my blog.
alienproxy
not rated yet Jul 29, 2011
FunkyDude, what you described is called "Natural Selection" and is a component of evolution.
Y8Q412VBZP21010
not rated yet Jul 29, 2011
FunkyDude, what you described is called "Natural Selection" and is a component of evolution.


I wasn't quite sure if he was making an observation or a criticism. But I dinged him anyway just for being inarticulate.