Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How cheetahs outpace greyhounds

21.06.2012
In a 0-60 mph stand off, most cars would be hard pressed to give a cheetah a run for its money, and at their highest recorded speed of 29m/s (65mph) cheetahs easily outstrip the fastest greyhounds.

But, according to Alan Wilson from the Royal Veterinary College, UK, there is no clear reason for the cheetah's exceptional performance. 'Cheetahs and greyhounds are known to use a rotary gallop and physically they are remarkably similar, yet there is this bewitching difference in maximum speed of almost a factor of two', he says.

Teaming up with Penny Hudson and Sandra Corr, Wilson decided to compare how cheetahs and greyhounds sprint to see if there were any mechanical differences between the two animals' movements and they publish their findings in The Journal of Experimental Biology at http://jeb.biologists.org.

Knowing that captive big cats are happy to chase a lure, the trio were confident that they could get the cheetahs at ZSL Whipsnade Zoo, UK, and the Ann van Dyk Cheetah Centre, South Africa, to sprint across force plates buried in a track in the animals' enclosure. The problem would be getting the valuable equipment to work in the open. 'Force plates are cosseted, loved pieces of equipment that people don't generally take outside of the lab and bury in the ground in the English summer', Wilson chuckles. However, after successfully installing eight force plates in the cheetahs' enclosure, along with four high speed cameras filming at 1000frames/s, Hudson tempted the cheetahs to gallop along the track with a piece of chicken attached to a truck starter motor while she measured the forces exerted on the animals' limbs, their body motion and footfall patterns. She also repeated the measurements on galloping greyhounds back in the lab, filming the animals at a slower 350frames/s.

But, when Hudson compared the animals' top speeds, she was surprised to see that the trained greyhounds galloped faster than captive cheetahs, clocking up a top speed of 19m/s compared with the cheetahs' 17.8m/s. Nevertheless, Hudson was able to identify clear differences in the animals' stride patterns that could explain how wild cheetahs would outpace the dogs.

When running at the same speed, the big cats' stride was slightly longer than the greyhounds', although the cheetahs compensated for this with a slightly lower stride frequency. Also, the cheetahs increased their stride frequency as they shifted up through the gears – running at 2.4strides/s at a leisurely 9m/s, rising to 3.2strides/s at their top speed of 17m/s – whereas the greyhounds maintained a constant stride rate around 3.5strides/s across their entire speed range. Wilson suspects that wild cats may be able to reach stride frequencies of 4strides/s, which, in combination with longer stride lengths, may allow them to outstrip their captive cousins and hit top speeds of 29m/s.

Also, when Hudson analysed the length of time that each animal's foot remained in contact with the ground – the stance time – she noticed that for some of the cheetah's limbs it was longer, and the team suspects that this may be another factor that contributes to the wild cheetah's record performance. Explaining that increasing the stance time reduces the peak loads on the animal's legs, Wilson says, '[with] a longer stance time the cheetah will get to the limiting load at higher speed than the greyhound'.

Speculating about the relatively poor performance of the captive cheetahs, Wilson suggests that they may lack motivation. 'They have lived in a zoo for several generations and have never had to run to catch food. They have probably never learned to run particularly', he says, adding, 'The next stage is to try to make measurements in wild cheetahs in the hope of seeing higher speeds.'

IF REPORTING ON THIS STORY, PLEASE MENTION THE JOURNAL OF EXPERIMENTAL BIOLOGY AS THE SOURCE AND, IF REPORTING ONLINE, PLEASE CARRY A LINK TO: http://jeb.biologists.org/content/215/14/2425.abstract

REFERENCE: Hudson, P. E., Corr, S. A. and Wilson, A. M. (2012). High speed galloping in the cheetah (Acinonyx jubatus) and the racing greyhound (Canis familiaris): spatio-temporal and kinetic characteristics. J. Exp. Biol. 215, 2425-2434.

This article is posted on this site to give advance access to other authorised media who may wish to report on this story. Full attribution is required, and if reporting online a link to jeb.biologists.com is also required. The story posted here is COPYRIGHTED. Therefore advance permission is required before any and every reproduction of each article in full. PLEASE CONTACT permissions@biologists.com

Kathryn Knight | EurekAlert!
Further information:
http://www.biologists.com

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>