Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cluttered Surfaces Baffle Echolocating Bats

14.12.2001


When it comes to locating a meal, insect-eating bats generally employ one of two foraging tactics: capturing prey in the air or snatching it from a substrate. Accordingly, the animals use different kinds of echolocation during these activities. Whereas aerial hunters tend toward longer calls with constant frequency, substrate-gleaning species generate short calls that sweep from low to high frequencies (FM echolocation). Less clear, however, is how effective the latter is at distinguishing the prey item from the substrate when the substrate contains clutter. Under such conditions, one would expect the background objects—leaf litter on the forest floor, for example—to produce their own echoes, which could mask those of the bat’s intended target. Now new research shows that bats have a third strategy for just this kind of tricky circumstance: they turn down the sonar and wait for the insect to reveal itself. The findings appear today in the journal Nature.



Raphaël Arlettaz of the University of Bern and colleagues studied the mouse-eared bat’s ability to obtain live and dead insects on clean and cluttered surfaces. As it turns out, the animals scored well when it came to capturing moving prey on both substrates and still prey on a smooth surface, but they labored to locate still prey on a complex surface. Additionally, the researchers found that bats attempting to pinpoint prey in the air or on smooth surfaces emitted so-called feeding buzzes. Those searching among the rubble, in contrast, emitted only faint calls or no calls at all for more than a second just before detecting prey. The scientists thus suggest that the bats listen for prey-generated sounds during this moment of silence, which would explain why they struggled to locate the dead prey in the leaf litter. "The low-intensity calls emitted during prey approach," the team writes, "may detect the immediate surroundings so the bats avoid colliding with obstacles or the ground."

According to the researchers, the study results indicate that echolocation does not provide a detailed picture of objects to substrate-gleaning bats. Indeed, when hunting among clutter, echolocation appears to render the bats "acoustically blind." This, they conclude, "suggests that FM echolocation is mainly adapted to orientation and capture of prey either in the open space or from simple backgrounds."

Kate Wong | Scientific American
Further information:
http://www.sciam.com/news/121301/3.html

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>