If you flaunt it, youve got it: How red-heads top the pecking order
Red-headed finches dominate their black-headed and yellow-headed peers by physical aggression and by the mere fact of being red-headed, according to research published today in the Proceedings of the Royal Society.
Copyright Sarah Pryke
University of New South Wales biologists made the discovery following experiments with stunningly colourful Gouldian finches (Erythrura gouldiae). Among Australias most endangered native birds, Gouldian finches are now restricted to small isolated populations across the tropical north.
The bird has a bright green upper body, blue rump, violet-purple chest, yellow breast and bright azure-blue collar. But its most distinctive feature is its head, which occurs in one of three discrete colours: red, yellow or black. This colour polymorphism makes the Gouldian finch unique, with three distinct forms all naturally occurring and inter-breeding in the same wild populations.
The scientists first experiment aimed to reveal if there were behavioural differences between birds that related to the three head colours.
Observing contests between two unfamiliar males over access to food, they found that red-headed males were more aggressive and dominant than black-headed males, while both red and black-headed males dominated yellow-headed males.
In their second experiment, the scientists experimentally changed the head colours of the birds by dying them red or black to discover whether head colour was a communication "signal" between birds.
"Birds were reluctant to compete with opponents that had red dyed heads, demonstrating that they pay attention to this signal of dominance and use it to avoid getting into fights," says one of the studys authors, Dr Sarah Pryke, a Research Fellow in the School of Biological, Earth and Environmental Sciences.
"Red-headed birds that were temporarily dyed were still the most aggressive. This shows that red-heads are truly very aggressive and that it pays black- and yellow-headed birds to avoid fights with them.
"These findings suggest that red-heads have a dominance advantage and will out-compete the other two in contests over limited resources like food and the best nesting sites.
"As well, they show how the expression of a discrete colour is linked to a behavioural trait, and give us a new insight into how colour signals evolve as a form of communication in animals."
Dr Sarah Pryke | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects
A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
Larsen C Ice Shelf rift finally breaks through
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...