Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Without words, bullfrogs communicate through stutters in their croaks

21.05.2004


Male bullfrogs communicate with other bullfrogs through calls made up of a series of croaks, some of which contain stutters, according to a new Brown University study which describes a pattern not previously identified in scientific literature.



Researchers recorded 2,536 calls from 32 male bullfrogs in natural chorus and analyzed the number of croaks in each call and the number of stutters in each croak. It is known that the male bullfrog’s call attracts females for mating, maintains territorial boundaries with other males, and indicates that the frog is healthy and aggressive.

“Some animals have evolved large, complex vocabularies to communicate, while others say a lot with very limited numbers of calls,” said Andrea Simmons, professor of psychology, who presented the findings at 75th meeting of the Acoustical Society of America Monday, May 24, 2004. “A fundamental question in the study of communication by sound is ‘how much information can a sender convey in a single sound’?”


Within a single vocalization, the frogs exhibited a pattern of croaks with and without stutters that appeared to have a communication function and did not simply represent that a male was getting tired, Simmons said.

An acoustic analysis showed the stutters followed certain rules: 100 percent of the recorded calls began with a croak containing no stutters; when the frogs started stuttering they generally did so within a croak that contained one stutter only; when they increased or decreased stutters from croak-to-croak, they did so by only a single stutter.

Stuttering did not occur because a frog was “running out of breath,” said the researchers. If that were the case, a less structured pattern of stutters would occur. More likely, the frog inserted stutters in the call to extend the length of his individual calls while reducing the amount of air exchange needed, similar to what occurs when opera singers insert vibrato in extended notes.

To determine how the frog’s calls were perceived, researchers played pre-recorded stuttering and non-stuttering calls through a loudspeaker to individual males. The frogs appeared to use non-stuttered calls for aggressive or territorial purposes. Males produced the stuttered calls more frequently at certain points during the breeding season, indicating the stuttering may be involved in attracting a mate.

Simmons conducted the study with Dianne Suggs, a graduating senior in psychology, who used it as the basis of her undergraduate honors thesis. Suggs was supported by a grant through the Undergraduate Teaching and Research Assistantship (UTRA) program. Simmons’ laboratory is supported by a research grant from the National Institutes of Health.

Kristen Cole | Brown University
Further information:
http://www.brown.edu/Administration/News_Bureau/2003-04/03-143.html

More articles from Life Sciences:

nachricht More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>