Pigeons Overrule Bumbling Leaders
"Follow the leader" isn't a given in a pigeon flock, if that leader isn't taking the correct route, a new study finds.
Just in time for the run-up to the US presidential election comes a reminder that elected leaders can be voted out of office if their constituents feel they're being misled.
Pigeon leaders, in this case.
In a new study, researchers from the University of Oxford's zoology department wanted to find out just how much sway the leader of a homing pigeon flock holds over the birds it leads in flight. Does the flock blindly follow the leader, or will it push back and influence the flight plan if its members feel all is not going well?
"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," explained the study's lead author, Oxford doctoral candidate Isobel Watts, in a statement.
To find out, the researchers used GPS trackers to monitor eight homing pigeon flocks over a course for which they were previously trained. They "clock-shifted" certain birds, artificially manipulating their day/night cycles by altering the light and dark periods spent in their enclosures, adjusting the birds' internal clocks 2-3 hours. Clock-shifted pigeons are a bit off, internally, and can't accurately match time of day with the sun's position in the sky, which messes with their sense of direction and turns them into less-than-perfect flock leaders.
"By manipulating the quality of the leader's information," said Watts, "we hoped to discover whether a poorly informed leader was still allowed to lead or whether the flock would 'overrule' inaccurate leadership."
In some experiments, only leader pigeons were clock-shifted. In others, the entire flock got the jet-lag treatment.
It turned out that when the entire flock was clock-shifted, the whole flock began to fall off course of its typical home-bound path. But, if only the leader was clock-shifted, the flock still managed to hold a steady course.
The GPS data showed that the misinformed leaders seemed to lose their leadership status in the latter case, spending less time leading other birds in flight.
How the group course-correction occurs remains an open question.
"The exact mechanism by which a flock is able to correct for misinformation coming from its leader is still unclear," said Watts. Either the leaders, doubting their own judgement, begin following their fellow flock-mates or the flock, realizing its leader isn't up to the job, takes control, she speculated.
Study co-author Dora Biro stressed the importance, to the birds, of being flexible about which bird is leading the way.
"Following a 'bad' leader could lead the whole flock astray," Biro said, "and the capacity to reorganize 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,'" she added.
Results of the study were published September 13 in the Royal Society journal Biology Letters.
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