A pigeon's degree of leadership could be predicted by its speed in earlier flights, according to a new study.
Previous studies had shown that flock leadership is unrelated to social dominance. Giving followers extra training flights does not promote them to a position of leadership either.
The new findings offer an elegantly simple explanation for the phenomenon of leadership in birds, with important implications for how spatial knowledge is generated and retained in navigating flocks.
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In the study, the researchers compared pigeons' relative influence over flock direction to their solo flight characteristics.
Their studies showed that a pigeon's degree of leadership could be predicted by its speed in earlier flights.
While many birds travel in flocks, homing pigeons are domestic and more easily studied than most.
"We can control the composition of the flocks and the starting points for their homeward journeys," said Benjamin Pettit, from the University of Oxford.
"We also have a good understanding of their individual spatial cognition, in particular how their homing routes develop over repeated flights in the same area," he added.
Recent developments in sensor technology also make it possible to explore how pigeon flocks are coordinated.
The latest GPS loggers allow the researchers to track not only the birds' overall routes, but also the sub-second time delays with which they react to each other while flying as a flock.
In solo flights, leaders didn't excel in navigation ability. When the researchers tested the birds individually after a series of flock flights, however, they found that leaders had learned straighter homing routes than followers.
"Some birds are naturally faster and consistently get to the front, where they end up doing more of the navigation, which means on future flights they know the way better," Pettit said.
"You can compare this to a 'passenger-driver' - like effect - drivers in a car have to pay attention while passengers are often unable to recall the route they were driven along, especially if they remained passive in the navigation process," he added.
A very simple, self-organising mechanism - such as that based on variation in speed - is sufficient for leadership to arise.
In addition, the new findings offer a mechanism through which leaders can improve in their roles over time, making increasingly better decisions that others can follow.
The study was published in the journal Current Biology.