Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bats Use Touch Receptors on Wings to Fly, Catch Prey, Study Finds

19.12.2005


Bats have an “ear” for flying in the dark because of a remarkable auditory talent that allows them to determine their physical environment by listening to echoes. But an Ohio University neurobiology professor says bats have a “feel” for it, too.


Bat wings show a series of raised domes with touch receptors. photo by: John Zook



John Zook’s studies of bat flight suggest that touch-sensitive receptors on bats’ wings help them maintain altitude and catch insects in midair. His preliminary findings, presented at the recent Society for Neuroscience meeting, revive part of a long-forgotten theory that bats use their sense of touch for nighttime navigation and hunting.

The theory that bats fly by feel was first proposed in the 1780s by French biologist Georges Cuvier, but faded in the 1930s when researchers discovered echolocation, a kind of biological sonar found in bats, dolphins and a few other animals. Bats use echolocation to identify and navigate their environment by emitting calls and listening to the echoes that return from various objects.


Zook believes the touch-sensitive receptors on bats’ wings work in conjunction with echolocation to make bats better, more accurate nocturnal hunters. Echolocation helps bats detect their surroundings, while the touch-sensitive receptors help them maintain their flight path and snag their prey.

Touch receptors take the form of tiny bumps, or raised domes, along the surface of bats’ wings. The domes contain Merkel cells, a type of “touch” cell common in bumps on the skin of most mammals, including humans. Bat touch domes are different, however, because they feature a tiny hair poking out of the center.

When Zook recorded the electrical activity of the Merkel cells, he found they were sensitive to air flowing across the wing. These cells were most active when airflow – particularly turbulent airflow – stimulates the hair. When a bat’s wing isn’t properly angled or curved during flight, air passing next to the wing can become turbulent. Merkel cells help bats stay aerodynamically sound by alerting them when their wing position or curve is incorrect, preventing the creatures from stalling in midair.

“It’s like a sail or a plane. When you change the curve of a wing a little bit, you get improved lift. But if you curve it too much, the bat – or plane – may suddenly lose lift, hitting a stall point and falling out of the air. These receptor cells give bats constant feedback about their wing positions,” said Zook, who has studied bats for more than 30 years, focusing on echolocation and the bat auditory system. The bat’s sense of touch has been a side interest since the early 1980s.

To test his hypothesis, Zook removed the delicate hairs from bats’ wings with a hair removal cream. Then he let them fly. The bats appeared to fly normally when following a straight path, but when they’d try to take a sharp turn, such as at the corner of a room, they would drop or even jump in altitude, sometimes erratically. When the hairs grew back, the bats resumed making turns normally.

“It was obvious they had trouble maintaining elevation on a turn,” he said. “Without the hairs, the bats were increasing the curve of their wings too much or not enough.”

The bats’ flight behavior also changed based on the area of the wing where the hairs were removed. For example, when Zook removed hairs along the trailing edge of the wings and on the membrane between the legs, the bats were able to fly and turn effectively, but they tended to pitch forward because they couldn’t control their in-flight balance.

Zook’s research also points to the importance of a second type of receptor cell in the membranous part of bats’ wings. Nerve recordings revealed that these receptors respond when the membrane stretches. Zook calls areas on the wing where these stretch-sensitive cells overlap “sweet spots” because they are where bats like to snag their prey. In the lab, Zook shot mealworms covered with flour into the air and recorded how the bats caught them. He could tell from the flour imprints on the wings that the bats caught their prey almost exclusively in the stretch-sensitive sweet spots.

Andrea Gibson | EurekAlert!
Further information:
http://www.ohio.edu

More articles from Life Sciences:

nachricht Programming cells with computer-like logic
27.07.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht Identified the component that allows a lethal bacteria to spread resistance to antibiotics
27.07.2017 | Institute for Research in Biomedicine (IRB Barcelona)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

Programming cells with computer-like logic

27.07.2017 | Life Sciences

Identified the component that allows a lethal bacteria to spread resistance to antibiotics

27.07.2017 | Life Sciences

Malaria Already Endemic in the Mediterranean by the Roman Period

27.07.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>