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 Exciting Plant Vacuoles
14.06.2019 | Julius-Maximilians-Universität Würzburg

nachricht A microscopic topographic map of cellular function
13.06.2019 | University of Missouri-Columbia

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

Im Focus: Cost-effective and individualized advanced electronic packaging in small batches now available

Fraunhofer IZM is joining the EUROPRACTICE IC Service platform. Together, the partners are making fan-out wafer level packaging (FOWLP) for electronic devices available and affordable even in small batches – and thus of interest to research institutes, universities, and SMEs. Costs can be significantly reduced by up to ten customers implementing individual fan-out wafer level packaging for their ICs or other components on a multi-project wafer. The target group includes any organization that does not produce in large quantities, but requires prototypes.

Research always means trying things out and daring to do new things. Research institutes, universities, and SMEs do not produce in large batches, but rather...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Concert of magnetic moments

14.06.2019 | Information Technology

Materials informatics reveals new class of super-hard alloys

14.06.2019 | Materials Sciences

New imaging modality targets cholesterol in arterial plaque

14.06.2019 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>