Zooming in for a safe flight: Study investigates spatial orientation in bats

Sep 01, 2014
bat

Bats emit ultrasound pulses and measure the echoes reflected from their surroundings. They have an extremely flexible internal navigation system that enables them to do this. A study published in Nature Communications shows that when a bat flies close to an object, the number of active neurons in the part of a bat's brain responsible for processing acoustic information about spatial positioning increases. This information helps bats to react quickly and avoid obstacles.

As , are perfectly adapted to a life without light. They emit echolocation sounds and use the delay between the reflected echoes to measure distance to obstacles or prey. In their brains, they have a spatial map representing different echo delays. A study carried out by researchers at Technische Universität München (TUM) has shown for the first time that this map dynamically adapts to external factors.

Closer objects appear larger

When a bat flies in too close to an object, the number of activated neurons in its brain increases. As a result, the object appears disproportionately larger on the bat's brain map than objects at a safe distance, as if it were magnified. "The map is similar to the navigation systems used in cars in that it shows bats the terrain in which they are moving," explains study director Dr. Uwe Firzlaff at the TUM Chair of Zoology. "The major difference, however, is that the bats' inbuilt system warns them of an impending collision by enhancing neuronal signals for objects that are in close proximity."

Bats constantly adapt their flight maneuvers to their surroundings to avoid collisions with buildings, trees or other animals. The ability to determine lateral distance to other objects also plays a key role here. Which is why bats process more spatial information than just echo delays. "Bats evaluate their own motion and map it against the lateral distance to objects," elaborates the researcher.

Brain processes complex spatial information

In addition to the echo reflection time, bats process the reflection angle of echoes. They also compare the sound volume of their calls with those of the reflected sound waves and measure the wave spectrum of the echo. "Our research has led us to conclude that bats display much more on their acoustic maps than just echo reflection."

The results show that the nerve cells interpret the bats' rapid responses to external stimuli by enlarging the active area in the brain to display important information. "We may have just uncovered one of the fundamental mechanisms that enables vertebrates to adapt flexibly to continuously changing environments," concludes Firzlaff.

Explore further: Bat in your house? Don't touch it or kill it

More information: Echo-acoustic flow dynamically modifies the cortical map of target range in bats; Sophia K. Bartenstein, Nadine Gerstenberg, Dieter Vanderelst, Herbert Peremans & Uwe Firzlaff; Nature Communications, DOI: 10.1038/ncomms5668

add to favorites email to friend print save as pdf

Related Stories

How bats 'hear' objects in their path

Nov 24, 2011

(PhysOrg.com) -- By placing real and virtual objects in the flight paths of bats, scientists at the Universities of Bristol and Munich have shed new light on how echolocation works.  Their research is ...

How bats stay on target despite the clutter (w/ Video)

Jul 28, 2011

In a paper published this week in Science, researchers at Brown University and from the Republic of Georgia have learned how bats can home in on a target, while nearly instantaneously taking account of and ...

Large moths need to hear better

Aug 19, 2013

Bats orient themselves through echolocation, and they find their prey by emitting calls and then process the echoes reflected back to them from the prey. Small insects reflect small echo signals, and large ...

Bats bolster brain hypothesis, maybe technology, too

Aug 15, 2014

Amid a neuroscience debate about how people and animals focus on distinct objects within cluttered scenes, some of the newest and best evidence comes from the way bats "see" with their ears, according to ...

Recommended for you

A vegetarian carnivorous plant

Dec 19, 2014

Carnivorous plants catch and digest tiny animals in order and derive benefits for their nutrition. Interestingly the trend towards vegetarianism seems to overcome carnivorous plants as well. The aquatic carnivorous bladderwort, ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

marko
not rated yet Sep 01, 2014
It is thought that bats echo location abilities have an inate understanding of special relativity in the acoustic context.

See the relevant Youtube videos of Professor Norman Wildberger.

https://www.youtu...AR-Xh9pQ

And

https://www.youtu...AR-Xh9pQ
betterexists
not rated yet Sep 01, 2014
When human cells transplanted into mice have been known to thrive & function normally, WHAT IS STOPPING the introduction of Bat's Nerve Cells or their Progenitor Cells in Various types of Lab Animals?
If only they can walk properly in dark like Bats when their eyes are shut up!
We can always attach a gadget to create Echos on the backs of those Lab Animals.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.