More minds together don’t lead to better ideas, at least as far as homing pigeons go. In fact, larger pigeon flocks aren’t any more accurate than small ones.
Biologists from the Max Planck Institute in Germany wanted to know how a group of pigeons decides which direction it thinks home is. The process, it turns out, is more similar to this year’s messy presidential primaries than you might suspect.
The researchers trained 66 pigeons to return to a loft, putting them in a basket and driving them up to 30 miles away before releasing them. When the pigeons tried to head home, they began by circling. During this time, the birds selected whom to follow, democratically choosing their leaders. Birds with ambition occasionally lurched out of the circle, trying to gain followers.
To test how group size changed the dynamic, the researchers released between 2 and 20 birds at a time. The larger the flock, the longer it spent choosing a direction—but its homing behavior didn’t improve, despite the extra time and brains.
The finding goes against the prevailing theory of pigeon navigation. Individual pigeons find their way using the Earth’s magnetic fields, which they sense using specialized cells with magnetic material that act as tiny compasses. Previous studies concluded that, while each pigeon doesn’t have a perfect compass, many imperfect compasses together leads to a more correct one. Yet a different principle seemed at play in this experiment.
Most likely, it’s because larger flocks have more leader candidates to sort through, but the quality of the candidates isn’t any better. In fact, the researchers concluded that the pigeons didn’t seem to choose leaders based on their navigational experience, at all. They just followed the bird that happened to be acting most like a leader.
“I think this is indeed likely to be the case,” said Dora Biro of Oxford University, who wasn’t involved in the study and is a member of the Oxford Navigation Group.
Benjamin Pettit of the Oxford Navigation Group found previously that pigeons tend to follow the quickest bird rather than the most experienced.
“The pigeons that flew fastest individually were more likely to lead flocks, regardless of the previous straightness of their homing routes,” he said.
Biro said this study was “a great attempt” at better understanding flock decision making. However, the researchers should have tracked the pigeons using GPS for the entirety of their journey, she argued. Pigeons continue making decisions throughout their journey that can improve their accuracy.