For homing pigeons, it takes speed to lead

How does a flock of homing pigeons decide who goes first? Is it charisma? Intelligence? Seniority?

The answer, it turns out, may be quite simple: speed.

According to a new study, the fastest pigeon takes the lead in flocks. And as a bird leads the pack, its leadership is reinforced by learning. The leading birds learn to navigate the most efficient route more quickly than the others, according to the paper published Wednesday in the journal Current Biology.

The researchers tested the birds both individually and in flocks, looking to see how fast they flew and if they took an efficient route.

“The faster birds showed a strong tendency to take the lead in flock flights regardless of their initial navigational ability,” zoologist and study author Benjamin Pettit tells The Christian Science Monitor in an interview. 

All the homing pigeons studied were released for solo flights first. The scientists noted how fast the birds flew and how well they navigated. Then, the birds flew as a flock from the same release site four times. After the flock flights, the birds flew the route solo again. 

“After their experience in flocks, it was those faster leaders that had improved most in their efficiency,” says Dr. Pettit. “So it seems that they were more effective at learning if they were a leader in the flock and were flying toward the front of the flock.”

This navigational learning could be likened to being a driver versus being a passenger in a car. Although traveling the same route, the driver is more likely than the passenger to remember the directions. 

In both the birds and the human scenario, it’s not clear what makes the leaders, or drivers, better learners. Perhaps it has to do with the concentration required or spacial learning. Or perhaps the followers are expending more energy trying to keep up, diverting resources away from navigation.

This learning was a surprise to Pettit. “We know that all of these pigeons could make the journey themselves, it wasn’t that any of them were particularly bad navigators,” he says. “From our experience releasing these pigeons on their own, we would expect all of them to improve over time.”

Pettit expects more research to investigate the interaction between learning and collective motion in these animals.

The birds selected for this study were relatively equally inexperienced with the routes the researchers had them navigate. But in the wild, a flock might not start off so uniform. 

That differing experience could complicate the role of speed in determining who leads. But, says Pettit, it would take a significant amount of experience to tip the balance. 

From the results, Pettit sees leadership as less related to social complexities and more related to differing individual abilities. “Leadership is a necessary consequence of the individual differences in the population,” he says. This is in contrast to “some kind of adaptive social complexity where they decided who to follow,” Pettit explains.

“Bird flocks are mesmerizing and beautiful phenomena of nature,” says Pettit. “They’re really quite spectacular to watch.”