 |
|
Whispering bats are 100 times louder than previously thought
December 12, 2008Whispering bats are shrieking
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. How could 'whispering' bats echolocate with puny 70decibel cries that barely carry at all? Teaming up with her long time collaborator Elizabeth Kalko from the Smithsonian Tropical Research Institute and student Signe Brinkløv, Surlykke decided to measure the volume of a pair of whispering bat species' calls to find out how loud the whisperers are. They publish their discovery that whispering bats are really shrieking in The Journal of Experimental Biology on 12th December 2008 at http://jeb.biologists.org.
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.
http://jeb.biologists.org
The Company of Biologists
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.
http://jeb.biologists.org
The Company of Biologists
Echolocation Current Events and Echolocation News RSSSpanish scientists develop echo-location in humans
A team of researchers from the University of Alcalá de Henares (UAH) has shown scientifically that human beings can develop echolocation, the system of acoustic signals used by dolphins and bats to explore their surroundings.
Bats recognize the individual voices of other bats
Bats can use the characteristics of other bats' voices to recognize each other, according to a study by researchers from the University of Tuebingen, Germany and the University of Applied Sciences in Konstanz, Germany.
Molecular evolution is echoed in bat ears
Bats' ability to echolocate may have evolved more than once, according to research published this week by Queen Mary, University of London scientists.
Why wind turbines can mean death for bats
Power-generating wind turbines have long been recognized as a potentially life-threatening hazard for birds. But at most wind facilities, bats actually die in much greater numbers.
Missing link shows bats flew first, developed echolocation later
The discovery of a remarkably well-preserved fossil representing the most primitive bat species known to date demonstrates that the animals evolved the ability to fly before they could echolocate.
Slow-motion video study shows shrews are highly sophisticated predators
Shrews are tiny mammals that have been widely characterized as simple and primitive. This traditional view is challenged by a new study of the hunting methods of an aquatic member of the species, the water shrew. It reveals remarkably sophisticated methods for detecting prey that allow it to catch small fish and aquatic insects as readily in the dark as in daylight.
Bats add their voice to the FOXP2 story
When it comes to the FOXP2 gene, humans have had most to shout about. Discoveries that mutations in this gene lead to speech defects and that the gene underwent changes around the time language evolved both implicate FOXP2 in the evolution of human language.
Migrating squid drove evolution of sonar in whales and dolphins, researchers argue
Behind the sailor's lore of fearsome battles between sperm whale and giant squid lies a deep question of evolution: How did these leviathans develop the underwater sonar needed to chase and catch squid in the inky depths"
Bats prey on nocturnally migrating songbirds
It was until now believed that nocturnally migrating songbirds, while venturing into the unfamiliar night sky for accomplishing their long, challenging trans-continental migrations, could at least release anti-predator vigilance thanks to the concealment of darkness.
Beaked Whales Perform Extreme Dives to Hunt Deepwater Prey
A study of ten beaked whales of two poorly understood species shows their foraging dives are deeper and longer than those reported for any other air-breathing species.
More Echolocation Current Events and Echolocation News Articles
 |
echolocation fruit bats (Performer) Echolocation is the debut album from Fruit Bats. Imaginary pop hits about the unsettling nature of the great outdoors, murderous fireflies and vengeful pigeons. Imagine Eno and Elton John wrecking a campfire sing-along. Timeless sounds finding the calm in absurdity. Echolocation creates a world where gentle harmonies and subtle guitars frame lines like "arms ripped off by shooting stars". Mandolin and marimbas lead into a chorus where “ The light refracts through the glass in your feet". Dirty country fiddles bend into synthesizer lines and icebergs into garlic fields. Where perfect falsetto pop mixes with images of urban writer’s block and Vikings high on mushrooms all in the same song. It’s sexual, space age country music about seeing the beauty in natural disaster. It makes... |
 |
Echolocation in Bats and Dolphins by Jeanette A. Thomas (Editor), Cynthia F. Moss (Editor), Marianne Vater (Editor) Although bats and dolphins live in very different environments, are vastly different in size, and hunt different kinds of prey, both groups have evolved similar sonar systems, known as echolocation, to locate food and navigate the skies and seas. While much research has been conducted over the past thirty years on echolocation in bats and dolphins, this volume is the first to compare what is known about echolocation in each group, to point out what information is missing, and to identify future areas of research. Echolocation in Bats and Dolphins consists of six sections: mechanisms of echolocation signal production; the anatomy and physiology of signal reception and interpretation; performance and cognition; ecological and evolutionary aspects of echolocation mammals; theoretical... |
 |
Echolocation Public Record (Primary Contributor) |
 |
EchoLocations by Diane Thiel (Author) At home with traditional forms and free verse patterns, Diane Thiel composes highly charged, evocative poems that celebrate and elucidate voyaging-in our own hearts and minds, to other lands, back and forth in time-the natural world, science, and her family's German heritage. Diane Thiel's poetry has appeared in The Best American Poetry 1999, The Hudson Review, Poetry, among others. She is the author of two chapbooks, Cleft in the Wall and The Minefield, both out from Aralia Press. She has an MFA from Brown University, and she teaches at the University of Miami. |
 |
ABC News Specials Medical Mysteries Series-Episode #3 Medical science has progressed exponentially in recent times, but scientists are still left with unanswered questions when it comes to the human body. "Medical Mysteries" looks at some of the rarest disorders and syndromes in medicine today. Meet a woman whose body exudes a strange and overwhelming smell that has resulted in constant embarrassment, leaving a job, and being ridiculed for years. Next, meet a boy who is blind, but that hasn't stopped him from "seeing." He rollerblades, rides his bike, even shoots hoops. He is one of the few known people who,like a bat or a dolphin, use echolocation to "see" by the sounds he makes. Next, learn about Foreign Accent Syndrome, where a person finds themselves speaking their native language but with a distinctly different accent, and they... |
 |
Echolocation by Public Record Public Record's second release finds the band in full-on collaboration mode as they join forces with 11 artists of differing musical backgrounds to remix and rethink five songs from the band's 2008 self-titled debut album. Echolocation boasts an original mixture of artists that should surprise those listeners expecting a typical brand of remix album. Individuals like Guy Picciottto (Fugazi, Rites of Spring), Alasdair MacLean (The Clientele), Mac McCaughan (Superchunk, Portastatic), and Quentin Stoltzfus (Mazarin) are here, remixing for the first time alongside famed indie rock producer/remixer Mark Robinson (Unrest, Air Miami). Also featured are remixes by some promising new and underground acts like A Sunny Day In Glasgow, Collette Columbirch, and Arc In Round. The inclusion of... |
 |
Echolocation by Angela Andrews (Author) Daily rhythms and family tales dominate this quietly impressive book of poems, which examines domestic life in order to reconfirm its virtues. Though the subject matter is uncompromisingly orthodox, with ruminations on having a baby in the home and another on the way, the writing uses undeniable grace and exactness to cut to the heart of what truly matters in life. |
|
|
Heavy Ornament (Portastatic "Heavy Thumbs" Remix) Public Record (Primary Contributor) |
|
Echolocation by Baze | |
|
Echolocation in animals by E. Sh Airapetiants (Author) |
| © 2009 BrightSurf.com |