Featured Research

from universities, journals, and other organizations

Whispering Bats Are Shrieking 100 Times Louder Than Previously Thought

Date:
December 20, 2008
Source:
Journal of Experimental Biology
Summary:
Some echo-locating bats seem to be really quiet, appearing to make echo-locating calls that are no louder than 70 decibels. But no one had successfully recorded their volume under natural conditions, until now. When researchers recorded whispering bats they found that some of them are shrieking 100 times louder than thought.

Annemarie Surlykke from the University of Southern Denmark is fascinated by echolocation. She really wants to know how it works. Surlykke equates the ultrasound cries that bats use for echolocation with the beam of light from a torch: you won't see much with the light from a small bulb but you could see several hundred metres with a powerful beam. Surlykke explains that it's the same with echolocating bats. Some have big powerful calls for perception over a long range, while others are said to whisper; which puzzled Surlykke.

Related Articles


How could 'whispering' bats echolocate with puny 70-decibel cries that barely carry at all? Teaming up with her long time collaborator Elizabeth Kalko from the Smithsonian Tropical Research Institute and student Signe Brinklψv, Surlykke decided to measure the volume of a pair of whispering bat species' calls to find out how loud the whisperers are. 

Travelling to the Smithsonian Research Institute's Barro Colorado Island in Panama, Surlykke decided to focus on two whispering members of the Phyllostomidae family: Artibeus jamaicensis and Macrophyllum macrophyllum. According to Surlykke, the Phyllostomidae family of bats are unique because of their remarkably diverse lifestyles and diets. Some feed on fast moving insects while others feast on fruit buried in trees, making them an ideal family to study to find out how echolocation works.

But measuring the volume of the bat's echolocation calls was extremely challenging. If Surlykke was going to get true volume measurements from hunting bats on the wing, she would have to be certain that the bats were facing head on and that she could measure their distance from the microphone that recorded the sound so that she could correct for the volume lost as the call travelled to the microphone. Setting up an array of four microphones, the team recorded 460 cries, which Surlykke eventually whittled down to 31 calls for M. macrophyllum and 19 for A. jamaicensis that she could use.

Correcting the volume measurements, Surlykke was delighted to find that far from whispering, the bats were shrieking. The tiny insectivore M. macrophyllum registered a top volume of 105decibel, while fruit feeding A. jamaicensis broke the record at 110decibel, a remarkable 100 times louder than a 70decibel bat whisper and almost twice as loud as A. jamaicensis.

Surlykke suspects that she can explain the differences in the animals' volumes by their different lifestyles. She explains that the relatively large A. jamaicensis feeds on fruit, which it probably locates through a combination of senses, including smell and short-range echolocation whispers. But the bats have to search over large areas to find fruiting trees, and Surlykke suspects that the bat uses its high volume, well-carrying shrieks for orientation in their complex forest environment.

However, tiny M. macrophyllum's lifestyle is completely different. They hunt for insects over water, scooping them up with their tail. Surlykke says that she suspected that M. macrophyllum would be louder because she couldn't see how the animals could locate moving insects with a low intensity echolocation call, but admits that she was amazed that they were so much louder and that they could also adjust the volume to match their prey.


Story Source:

The above story is based on materials provided by Journal of Experimental Biology. The original article was written by Kathryn Phillips. Note: Materials may be edited for content and length.


Journal Reference:

  1. Brinklψv, S., Kalko, E. K. V. and Surlykke, A. Intense echolocation calls from two 'whispering' bats, Artibeus jamaicensis and Macrophyllum macrophyllum (Phyllostomidae). Journal of Experimental Biology, Dec 12, 2008; 212, 11-20

Cite This Page:

Journal of Experimental Biology. "Whispering Bats Are Shrieking 100 Times Louder Than Previously Thought." ScienceDaily. ScienceDaily, 20 December 2008. <www.sciencedaily.com/releases/2008/12/081212080548.htm>.
Journal of Experimental Biology. (2008, December 20). Whispering Bats Are Shrieking 100 Times Louder Than Previously Thought. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2008/12/081212080548.htm
Journal of Experimental Biology. "Whispering Bats Are Shrieking 100 Times Louder Than Previously Thought." ScienceDaily. www.sciencedaily.com/releases/2008/12/081212080548.htm (accessed October 31, 2014).

Share This



More Plants & Animals News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How A Chorus Led Scientists To A New Frog Species

How A Chorus Led Scientists To A New Frog Species

Newsy (Oct. 30, 2014) — A frog noticed by a conservationist on New York's Staten Island has been confirmed as a new species after extensive study and genetic testing. Video provided by Newsy
Powered by NewsLook.com
Surfer Accidentally Stands on Shark, Gets Bitten

Surfer Accidentally Stands on Shark, Gets Bitten

AP (Oct. 30, 2014) — A 20-year-old competition surfer said on Thursday he accidentally stepped on a shark's head before it bit him off the Australian east coast. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Ebola Inflicts Heavy Toll on Guinean Potato Trade

Ebola Inflicts Heavy Toll on Guinean Potato Trade

AFP (Oct. 30, 2014) — The Ebola epidemic has seen Senegal and Guinea Bissau close its borders with Guinea and the economic consequences have started to be felt, especially in Fouta Djallon, where the renowned potato industry has been hit hard. Duration: 02:01 Video provided by AFP
Powered by NewsLook.com
Genetically Altered Glowing Flower on Display in Tokyo

Genetically Altered Glowing Flower on Display in Tokyo

Reuters - Innovations Video Online (Oct. 30, 2014) — Just in time for Halloween, a glowing flower goes on display in Tokyo. Instead of sorcery and magic, its creators used science to genetically modify the flower, adding a naturally fluorescent plankton protein to its genetic mix. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins