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:
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...