Featured Research

from universities, journals, and other organizations

Tiger beetle's chase highlights mechanical law

Date:
April 15, 2014
Source:
Cornell University
Summary:
If an insect drew a line as it chased its next meal, the resulting pattern would be a tangled mess. But there’s method to that mess: It turns out the tiger beetle, known for its speed and agility, does an optimal reorientation dance as it chases its prey at blinding speeds.

A visual representation of a tracked tiger beetle’s trajectories as it chases prey. By observing a beetle’s chase, scientists have derived a physical law that it follows to optimize its predation strategies.
Credit: Jane Wang

If an insect drew a line as it chased its next meal, the resulting pattern would be a tangled mess. But there's method to that mess, says Jane Wang, a Cornell University professor of mechanical engineering and physics, who tries to find simple physical explanations for complex, hardwired animal behaviors.

It turns out the tiger beetle, known for its speed and agility, does an optimal reorientation dance as it chases its prey at blinding speeds. Publishing online April 9 in the Journal of the Royal Society Interface, Wang and colleagues used high-speed cameras and statistical analysis to reveal a proportional control law in which the angular position of prey, relative to the beetle's body axis, drives the beetle's angular velocity with a delay of 28 milliseconds. That's about a half-stride in beetle terms.

These observations led Wang to propose a physical interpretation of the behavior: that to turn toward its prey, the beetle, on average, exerts a sideways force proportional to the prey's angular position, measured a half-stride earlier.

"The idea is to find laws that animals use to intercept their prey," Wang said. "We do it, too [interception] -- when trying to catch a baseball, or when chasing someone. But since insects have a smaller number of neurons, their behaviors are more likely hardwired, which makes it possible for us to find and understand the rules they follow."

Why the tiger beetle? It's a nice model system, Wang said, which she learned after attending a talk several years ago by Cornell entomology professor Cole Gilbert, who studies neural mechanisms of behavior in arthropods and is a paper co-author. Andreas Haselsteiner, the paper's first author, was a visiting student in Wang's lab and designed the experiments.

For the experiments, a "dummy prey" -- a black bead -- was dangled in front of the beetle, which, mistaking the bead for a meal, would give chase. Its chasing patterns were recorded with a high-speed camera.

From their analysis emerged a macroscopic description of the animal's movements, which reveals an internal time scale that governs the beetle's sensing-to-actuation system and a close-to-optimal gain value in the control algorithm, Wang said.

From an evolutionary point of view, the sensing and moving are intimately connected, Wang continued. Some of the hundreds of thousands of neurons that function for sight are directly connected to the machinery for locomotion, which is directly related to the animal's instinct to survive -- that is, eat. Thus, studying how animals move can provide insight into how they sense their environment, and vice versa, she said.


Story Source:

The above story is based on materials provided by Cornell University. The original article was written by Anne Ju. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. F. Haselsteiner, C. Gilbert, Z. J. Wang. Tiger beetles pursue prey using a proportional control law with a delay of one half-stride. Journal of The Royal Society Interface, 2014; 11 (95): 20140216 DOI: 10.1098/rsif.2014.0216

Cite This Page:

Cornell University. "Tiger beetle's chase highlights mechanical law." ScienceDaily. ScienceDaily, 15 April 2014. <www.sciencedaily.com/releases/2014/04/140415133815.htm>.
Cornell University. (2014, April 15). Tiger beetle's chase highlights mechanical law. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2014/04/140415133815.htm
Cornell University. "Tiger beetle's chase highlights mechanical law." ScienceDaily. www.sciencedaily.com/releases/2014/04/140415133815.htm (accessed October 21, 2014).

Share This



More Plants & Animals News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com
Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Goliath Spider Will Give You Nightmares

Goliath Spider Will Give You Nightmares

Buzz60 (Oct. 20, 2014) An entomologist stumbled upon a South American Goliath Birdeater. With a name like that, you know it's a terrifying creepy crawler. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
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