Research news: Bigger flocks are ‘smarter’ flocks
In humans, larger groups of people tend to include individuals with a wide variety of skills and experiences, allowing larger groups to solve problems better than individuals or smaller groups. Recent research on European tits, cousins of North American chickadees, reveal that the same may be true in avian societies. The researchers tested the problem solving ability of wild birds by designing a feeder with a twist. The birds were required to pull two levers before seeds would be dispensed from the feeder. Could the birds overcome this novel challenge?
The birds were certainly interested in the feeders: 4,775 attempts were made to solve the problem by 197 individual birds. Of these attempts, 313 were successful (7.9%). Individuals in larger flocks were more likely to solve the problem and gain the food reward than were birds in smaller flocks. The chances of solving the problem may be related to how flocking influences the risk of exposure to predators. With many eyes watching for predators, each individual bird is afforded the luxury of more time to focus on feeding. Further, the chances of solving the problem increased if the feeder was located close to protective tree cover, suggesting that feeding innovation is constrained by the threats posed be predators.
The “pool of competence” hypothesis predicts that larger groups include individuals with a broad diversity of skills and experiences that increase the collective ability of the group to overcome challenges. Although this hypothesis has been supported in other animal societies, this is the first study to test the idea on flocks of free-living birds. Indeed, flocks including an experienced bird (one that had been previously exposed to the special feeder) were more likely to ultimately solve the problem than flocks entirely composed of naive individuals. Because the feeders were designed to dispense many seeds when the problem was solved, all individuals living in the flocks benefited. This benefit of living in large groups likely holds under natural conditions, where all flock members may be able to exploit a novel food source discovered by one individual.
Source: Morand-Ferron, J. and J. L. Quinn. 2011. Larger groups of passerines are more efficient problem solvers in the wild. Proceedings of the National Academy of Sciences 108:15898-15903.