Butterfly's Wing Ears May Detect Birds

LiveScience ^ | 26 October 2009 | Jeanna Bryner

[Daffynition]

A butterfly species equipped with tiny ears on its wings can distinguish between high and low pitch sounds, possibly as a way to listen in on nearby birds, new research suggests.

Scientists thought butterflies were deaf until 1912 when the first butterfly ears were identified. Only in the past decade or so have researchers examined the anatomy and physiology of butterfly ears, which they are finding to be quite diverse and present in several butterfly species.

The latest discovery was made with the blue morpho butterfly (Morpho peleides), which dazzles with its bright-blue wing coloration when it flits about in its native Central and South America.

Simple setup

Scientists knew from relatively recent research that the morpho sports simple wing ears. In the new study, Kathleen Lucas of the University of Bristol in England and her colleagues were interested in the odd-looking hearing membrane that sits at the base of the blue morpho's wing. The tympanal membrane, as it is called, is oval-shaped with a dome at its center that kind of resembles the yolk at the center of a fried egg, Lucas said.

Sound waves from, say, crackling leaves or a singing bird hit the membrane and get converted into nerve impulses by nearby sensory organs. Those impulses are picked up by nerve cells.

To figure out how the fried-egg membrane helped the butterfly hear, the researchers played sounds of various frequencies within the butterfly's estimated hearing range, between 1,000 Hertz and 5,000 Hertz. For comparison, our hearing range extends from 20 Hz to 20,000 Hz, though most speech lies between 100 Hz and 4,000 Hz.

[snip]

[Daffynition]

The blue morpho butterfly shows off its brightly colored wings when in flight. But at rest, with closed wings, the butterfly reveals a dull brown color that helps the animal blend in with its surroundings. Credit: Kathleen Lucas.

The simple ear of the blue morpho butterfly is tiny (shown here close-up) and is located at the base of the animal's wings. Credit: Kathleen Lucas.

The simple ear structure, which looks like a tiny piece of stretched material (see translucent spot where butterfly wing meets the body), may be able to differentiate between different frequency sounds, according to new research. Credit: Kathleen Lucas.

[JoeProBono]

[Daffynition]

[JoeProBono]

[Daffynition]

[Deaf Smith]

Texas A&M did a study years ago on grasshoppers and concluded that they had ears in their legs.

As a baseline starting point, each test bug was subjected to a horn blast and noted that all would jump.

As the research progressed, the legs of each grasshopper were removed one at a time and the test bug again subjected to a horn blast, noting that the test bugs would jump at the sound.

After the last leg of each test bug was removed and again subjected to the horn blast, the test bugs did not move and remained motionless. The testing continued for several more months to verify the results.

It was then determined that if you remove all the legs of a grasshopper, they go deaf.

[JoeProBono]

[JoeProBono]

[SunkenCiv]

Scientists thought butterflies were deaf until 1912 when the first butterfly ears were identified.

Imagine what the butterflies must think of the scientists. :')