The team, led by Leah Williams and Dr Claudia Mettke-Hofmann from Liverpool John Moores University, found that red-headed birds have aggressive tendencies, while those with black heads are bold and take more risks than their peers.
This is only the second time researchers have demonstrated such a strong link between personality and colour. The only other study showed that dark, male Hermann’s tortoises are both more aggressive and bolder than paler males.
‘We think that head colour is used as a signal of personality to other birds in the flock, so they know who to associate with,’ says Williams, who studied the birds as part of her PhD project.
Scientists first noticed a link between animals’ different colours and various aspects of their behaviour such as aggression, sexual behaviour and predator-avoidance tactics in the early 90s. Red, for example, has long been associated with aggression in cichlids, other birds, reptiles, primates and even us.