Featured Research

from universities, journals, and other organizations

Whale communication could explain how extreme ultrasonic bushcrickets transfer sound

Date:
May 19, 2014
Source:
University of Lincoln
Summary:
Ultrasonic bushcrickets could be using a similar method to communicate as that used by whales, according to newly published research. Katydid species that have extreme ultrasonic frequencies face a problem: ultrasounds travelling in air suffer excess attenuation (weakening) because the wavelength is too short, therefore objects in the dispersive path, such as leaves and branches, interfere and degrade the signal. Sound attenuation is also imposed by environmental conditions such as temperature and humidity.

Female ultrasonic katydid.
Credit: Image courtesy of University of Lincoln

Ultrasonic bushcrickets could be using a similar method to communicate as that used by whales, according to newly published research.

Dr Fernando Montealegre-Zapata, and his student Fabio Sarria-S from the School of Life Sciences, University of Lincoln, UK, studied the katydids or bushcrickets ultrasonic call frequencies at Gorgona National Natural Park -- an extremely humid rainforest located on a Colombian island in the Pacific Ocean.

Katydid species that have extreme ultrasonic frequencies face a problem: ultrasounds traveling in air suffer excess attenuation (weakening) because the wavelength is too short, therefore objects in the dispersive path, such as leaves and branches, interfere and degrade the signal. Sound attenuation is also imposed by environmental conditions such as temperature and humidity. Therefore Dr Montealegre-Z set out to test the hypothesis that the katydids should prefer microhabitats that favor efficient signal transmission.

The team studied 25 species of katydids, which used a variety of song frequencies, ranging between 9 and 150 kHz. It was observed that species with extreme frequencies (>120 kHz) prefer habitats above 12 metres but below the canopy where the vegetation is not cluttered. Ultrasonus (© F. Sarria-S & F. Montealegre-Z), a new genus incorporating three new species with the most extreme ultrasonic signals ever recorded in arthropods, is an example.

Dr Montealegre-Z said: "We think these insects use some kind of environmental channel to broadcast their calls at long distances. For instance, previous research suggests that whales can send a signal from one continent to another because they use the special conditions of the ocean. The ocean offers an amazing 'channeling' property that is a function of depth and temperature (sound travels faster at the top and bottom of the ocean, slower in the middle), and salinity. Refraction of waves then causes sound to be trapped in a region of low velocity sound transmission.So, whales can send a signal channeled within this region from one continent to the other in a few hours.

"We think a comparable system occurs in the rainforest, where the call of extreme ultrasonic katydids has a similar effect of being able to travel longer distances through the air at that particular height. Of course the ocean and the air are environments with enormous differences for sound propagation. In the ocean sound travels five times the speed it reaches in air."

A paper pointing to this hypothesis has been published in the international Journal of Tropical Biology and Conservation.

The typical role of katydids' singing is to communicate over long distances with the usual calling song produced by males to attract females. But ultrasonic signals are transmitted with difficulty as the distance increases between transmitter and receiver, and the environment conditions are adverse as in a humid rain forest.

This study investigated high frequency signals and space distribution in a vertical stratification.

Dr Montealegre-Z added: "The diversity of insects that produce sound in the tropics challenges our understanding of animal communication mechanisms and their evolution. The use of extremely high frequencies by certain South American katydids suggests unknown acoustic mechanisms responsible for the acoustic energy and the tuning of these signals.

"From this study we can hypothesize that the altitude preferred by these ultrasonic katydids could be situated in an air layer of low-velocity sound transmissionoptimal for the broadcast of sounds with extreme high frequency. It is possible that at this altitude, with little vegetation and a large acoustic space, environmental types of channels exist to promote the propagation of ultrasonic sounds at long distances."

Dr Montealegre-Z now plans to measure the acoustic conditions at this level of the rainforest to directly test this hypothesis.

The article can be found online at: http://bioacousticssensorybiology.weebly.com/uploads/1/5/1/2/15122314/montealegre_et_al-arboreal_katydids2014.pdf


Story Source:

The above story is based on materials provided by University of Lincoln. Note: Materials may be edited for content and length.


Journal Reference:

  1. Fernando Montealegre-Z, Fabio A. Sarria, Marνa Cleopatra Pimienta & Andrew C. Mason. Lack of correlation between vertical distribution and carrier frequency, and preference for open spaces in arboreal katydids that use extreme ultrasound, in Gorgona, Colombia (Orthoptera: Tettigoniidae). Journal of Tropical Biology and Conservation, May 2014

Cite This Page:

University of Lincoln. "Whale communication could explain how extreme ultrasonic bushcrickets transfer sound." ScienceDaily. ScienceDaily, 19 May 2014. <www.sciencedaily.com/releases/2014/05/140519092253.htm>.
University of Lincoln. (2014, May 19). Whale communication could explain how extreme ultrasonic bushcrickets transfer sound. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2014/05/140519092253.htm
University of Lincoln. "Whale communication could explain how extreme ultrasonic bushcrickets transfer sound." ScienceDaily. www.sciencedaily.com/releases/2014/05/140519092253.htm (accessed October 1, 2014).

Share This



More Plants & Animals News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Earth Has Lost Half Its Vertebrate Wildlife Since 1970: WWF

Newsy (Sep. 30, 2014) — A new study published by the World Wide Fund for Nature found that more than half of the world's wildlife population has declined since 1970. Video provided by Newsy
Powered by NewsLook.com
Dolphins Might Use Earth's Magnetic Field As A GPS

Dolphins Might Use Earth's Magnetic Field As A GPS

Newsy (Sep. 30, 2014) — A study released Monday suggests dolphins might be able to sense the Earth's magnetic field and possibly use it as a means of navigation. Video provided by Newsy
Powered by NewsLook.com
How To Battle Stink Bug Season

How To Battle Stink Bug Season

Newsy (Sep. 30, 2014) — Homeowners in 33 states grapple with stink bugs moving indoors at this time of year. Here are a few tips to avoid stink bug infestations. Video provided by Newsy
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