Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clicking knees are antelopes’ way of saying ‘back off’

04.11.2008
Knee clicking can establish mating rights among antelopes. A study of eland antelopes, published in the open access journal BMC Biology, has uncovered the dominance displays used by males to settle disputes over access to fertile females, without resorting to genuine violence.

Jakob Bro-Jørgensen from the Zoological Society of London and Torben Dabelsteen from the University of Copenhagen studied antelopes within a 400km2 area of Kenya.

They found that the males (bulls) use a selection of signals to make competitors aware of their fighting ability, based on three different factors, body size, age and aggression. According to Bro-Jørgensen, “Rivals often use signals to broadcast their fighting ability and thereby settle conflicts without incurring the high costs associated with actual fighting”.

As well as the knee clicks, which are shown to be a reliable indicator of body size, the researchers found that the size of a bull’s dewlap is related to age. The authors said, “Age is a good proxy for fighting experience and may also demonstrate that a bull has ‘nothing to lose’ and will therefore be a more risk-prone and dangerous adversary”.

Finally, hair darkness reflects yet another underlying variable, most likely androgen-related aggressiveness. All of these indicators serve the useful purpose of facilitating assessment by a bull’s rivals and avoiding wasteful conflict.

The antelopes’ knee clicks, which can be heard several hundred metres away, are thought to be produced by a tendon slipping over one of the leg bones and, according to the authors, this can explain why they correlate with body size, “The tendon in this case behaves like a string being plucked, and the frequency of the sound from a string correlates negatively with both its length and diameter. Thus, most importantly, depth of the sound is predicted to increase with skeletal measures”.

Graeme Baldwin | alfa
Further information:
http://www.biomedcentral.com/

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Safe glide at total engine failure with ELA-inside

27.02.2017 | Information Technology

Fraunhofer IFAM expands its R&D work on Coatings for protection against corrosion and marine growth

27.02.2017 | Materials Sciences

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>