Homing pigeons can improve their navigational efficiency by sharing knowledge among their group. This behavior has only be seen before in humans and some other primates, scientists at Oxford University say.
Before the internet, telephone, radio or even the telegraph, people favored homing pigeons to communicate over very long distances. Even across many hundreds of miles, these remarkable birds are able to find their way home no matter how disorientating the terrain may be. It was only recently that scientists came to understand how the homing pigeon uses its own natural GPS. According to the U.S. Geological Survey, the birds use low-frequency waves emanating from the Earth itself to mentally map their environments and navigate back to their lofts.
As if it weren't enough homing pigeons can hear down to about 0.1 Hertz (humans only hear in the 20 Hz - 20kHz range), Takao Sasaki and Dora Biro from Oxford University claim the birds are also capable of passing down knowledge.
They prove this fact by gradually removing and replacing individuals in pairs of homing pigeons that were tasked with various navigational tasks. The team released ten chains of homing pigeons from the same time and continuously replaced birds familiar with the route with inexperienced ones which had never flown the route.
In time, the homing performance of the pairs improved over generations (simulated by replacing birds) as the pigeons chose more streamlined, more efficient routes. Later generation groups also outperformed pigeons that flew solo or in groups that had never seen a change in membership.
Most importantly, consecutive generations of the same chain of pigeon pairs used more similar homing routes suggesting there's a 'pigeon culture' where cross-generational knowledge transfer is in effect.
"At one stage scientists thought that only humans had the cognitive capacity to accumulate knowledge as a society. Our study shows that pigeons share these abilities with humans, at least to the extent that they are capable of improving on a behavioural solution progressively over time. Nonetheless, we do not claim that they achieve this through the same processes," said Takao Sasaki, co-author and Research Fellow in the Department of Zoology.
That's not to say that pigeon culture is akin to human culture. As knowledge accumulates and gets shared among many people, not only does human culture gets passed on across generations, it also increases in complexity. That's not the case with homing pigeon knowledge. Their knowledge-sharing increases efficiency but not necessarily the complexity of behavior.
Another notable observation made by the researchers is that the gradual improvement in route efficiency didn't arise from some novel 'idea' put forth by one individual. Instead, each generation came with a collective intelligence background which arose as the birds solved problems together. The pigeon, of all birds, seems to confirm that 'two heads are better than one.'
Next, the researchers will focus on investing knowledge sharing and accumulation in other multi-generational species.
Journal reference: Takao Sasaki, Dora Biro. Cumulative culture can emerge from collective intelligence in animal groups. Nature Communications, 2017; 8: 15049 DOI: 10.1038/ncomms15049