The ability to collectively process information and make joint decisions is important for many social animals. It is known that, for example, bees, primates and humans possess “collective intelligence”, but so far his research has focused on single manifestations. Less clear is how different species accumulate and transfer individual experiences to the group and, in particular, through generations. This process, called the “cumulative culture of evolution” (described in the framework of the theory of double heredity), is associated with the need to solve similar problems, such as navigation under given conditions. The interaction of collective intelligence and cultural evolution has also not been studied enough.
To eliminate this gap, British ornithologists conducted an experiment with 60 gray dove (Columba livia). The animals were divided into ten groups, after which one bird from each group was released 12 times from the camp site of Greenhill Farm to the breeding site on the basis of Oxford University. After the formation of sustainable routes, the individuals performed 12 more flights paired with pigeons, to which the exact direction was unknown. Thus, successively replacing one bird in a pair, the authors experienced the cultural evolution of five “generations” in all ten groups. As a control, there were 30 pigeons, which were released as part of single or pair flights without mixing with other birds. The animal routes were studied using GPS navigators.
Routes in experimental and control groups. The comparison was conducted on the flights of the fifth generation (black color) / © Takao Sasaki et al., Nature Communications, 2017
The analysis showed that the efficiency of flights (the difference between the distance to the object – 8.6 kilometers and the length of the flight) in the experimental groups increased over 12 sessions. In control groups, the indicator was unstable: doves not included in the culture transfer process created and repeated their routes until the tests were completed. At the same time, the mixing of the “experienced” bird and the “beginner” first worsened the efficiency, but sharply increased it with subsequent flights. In comparison to the final flights in different groups, the change of pigeons reduced the distance to the breeding site by 1.2 kilometers – in isolated individuals the distance decreased by 0.05 kilometers (single flights) or increased by 0.04 kilometers (pairs).
It is noteworthy that the specifics of the routes that pioneered the experimental pairs were preserved up to three “generations”. Approximately from the fourth “generation” flights on the average were carried out on a straight line and converged in common points. According to scientists, the data obtained indicate the presence of cumulative cultural evolution in pigeons. This, in particular, is confirmed by the higher efficiency of mixed pairs compared to pairs from control groups: in the absence of information from other individuals, the latter not only did not reduce, but even increased the length of the route. The collective intelligence of these birds is indicated by the alleged ability to take into account information that increases productivity, and to abandon the others.
Pigeons have a cultural evolution
