Pigeons can stage a coo when leader of flock not up to scratch
Pigeons may have grasped the principles of democracy long before the ancient Greeks, a new study has shown.
Homing pigeon leaders who are not up to the job can be removed from office by proletariat flock members, scientists found.
In pigeon society, the fastest birds tend to become flock leaders and take primary responsibility for navigation.
The new study used a clock-shifting technique to interfere with pigeons' sense of direction by altering their perception of day and night.
Eight flocks each consisting of five birds tracked by GPS took part in the experiment.
Sometimes only the leader was clock-shifted, while on other occasions either the whole flock or no birds at all underwent clock-shifting.
Researcher Isobel Watts, from Oxford University, said: "Previous research in homing pigeons has identified a navigational leadership hierarchy where an individual's position in the hierarchy reflects its weight of contribution in the decision-making process.
"In this study, we were interested in how much control the 'top' bird actually has over the flock's decisions during homing.
"What we found was that when the whole flock was clock-shifted, the flock tended to deviate from its normal homeward flight path, whereas when solely the leader was clock-shifted, the flock was generally able to stay on course.
"Interestingly, we saw from GPS data on flock positions that misinformed leaders tended to lose their place at the top of the hierarchy, spending less time at the head of the flock and less time being followed in their movements by others."
She added: "The exact mechanism by which a flock is able to correct for misinformation coming from its leader is still unclear. However, we can speculate that it may be due to either misinformed flock leaders doubting their own abilities and paying more attention to what their flock-mates appear to be doing, or the flock members recognising weakness in the leader and taking more control themselves."
The findings are published in the Royal Society journal Biology Letters.
Pigeons rely on an internal "sun compass" to navigate which is closely linked to the day-night cycle.
Birds had their internal clocks re-set to an artificially shifted cycle by being placed in chambers in which the light could be altered.
Co-author Dr Dora Biro, also from Oxford University, said: "Although homing pigeon flocks have fairly stable hierarchical decision-making structures, our results show that they also demonstrate flexibility, and, crucially, they do so in a situation where the performance of the whole flock would suffer if they were inflexible.
"Following a 'bad' leader could lead the whole flock astray, and the capacity to reorganise the leadership hierarchy in this case allows them to stay on course. This could be particularly important in migratory bird species, where getting lost during a trip could be a matter of life and death."