Finches' personalities 'shown by head colour'
Gouldian finches have different personalities depending on the colour of their heads, researchers have found.
Scientists from Liverpool John Moores University and The Royal Veterinary College investigated the "highly sociable" Australian birds.
The team set the finches a series of behavioural tests to understand the purpose of their bright appearance.
They found that red-headed finches were more aggressive, while black-headed birds were bolder and took more risks.
The findings are published in the journal Animal Behaviour.
"Our idea is that the colour signals their behavioural tactics," said lead researcher Leah Williams.
She explained that the research also suggests that "bolder" black-headed finches may act as "leaders" in a group.
Gouldian finches are found in open, subtropical woodland and are known for their colourful plumage.
In the wild, the majority of the birds have black or red heads, although a very small number are yellow-headed.
When Gouldian finches first hatch "they're actually all an olive brown colour," Ms Williams told BBC Nature.
"After their first moult, when they're a couple of months old, that's when they get their colour."
Colour communication in nature:
- Adult Phayre's leaf monkeys are a dull shade of grey but they are born bright orange so that it is easy for the adults to keep an eye on the babies
- Humboldt squid are sometimes called "the red devil" because of their ability to flash red when angered or excited
- The panther chameleon of Madagascar communicates by changing colour. A chameleon can switch from cool green to angry red in an instant
To test for aggressiveness, the team put out a feeder for two hungry birds, but with only enough room for one to feed.
The red-headed finches displayed a more "fiery personality" than their black-headed peers, by displacing each other from the feeder and threatening other birds with an open beak.
"The black-headed birds stay away from the red-headed birds because they're signalling that they're aggressive, and this stops them getting into an escalated conflict," said Ms Williams.
Black-headed birds, however, were found to be greater "risk-takers" around predators.
Researchers presented the finches with a cardboard cut-out silhouette of a hawk. After fleeing from the feeder, the black-headed finches returned faster than their red-headed peers after the "danger" had passed.
Black-headed finches were also quicker in approaching unfamiliar objects, such as bundles of string prepared by researchers. This showed them to be bolder than their red-headed counterparts.
The research team now plans to find out if it is the birds' head colour that influences their personality, or whether it could be the other way round.
"The next step is to find out which birds associate with which," said Ms Williams.
"Do reds hang out with blacks and do they do better for that?"
The study was funded by the Natural Environment Research Council (NERC) and the Higher Education Funding Council for England (HEFCE).