IN THE Animal Mind, Canadian philosopher Kristin Andrews devotes a chapter to “culture”. She uses the term as an anthropologist might, aware that the idea of animals exhibiting culture “might sound funny at first”.
“It’s the study of what sorts of differences there are between animals of the same species,” she says. She cites the example of Keiko the orca star of the film Free Willy. Attempts to return Keiko to the wild, costing $20m, failed. Unable to readapt to the orca culture of his childhood, he was rebuffed by his wild peers. Having lost the ability to hunt, he starved. Keiko died in a Norwegian fjord in 2003.
There are Irish animal cultures. Mountain hares are found right down to sea level here, whereas they frequent only high ground elsewhere. Twentieth-century foxes became townies. Swallows and swifts now breed exclusively in buildings. Gulls have undergone several cultural changes. They learned to follow the plough and then began scavenging town dumps. Nesting on town roofs was first recorded in the 1920s. Now they snatch people’s lunches in St Stephen’s Green.
I once trekked through the famous laurel woods of Madeira National Park, trying to identify a bird with an unfamiliar song. The caller turned out to be a chaffinch. Birdsong dialects are widespread. Blow-ins mimic the vocalisations of the locals, the better to gain acceptance in their adopted locations. Tits learned to open milk bottles to get at the cream. What environmental factors trigger such cultural changes?
Scientists at the Max Planck Institute, studying the behaviour of great tits, found that cultural traits are picked up from “immigrants”. Great tits were trapped in the woods around Konstanz. Taken into captivity, they were kept in 18 separate groups of six. Each group was presented with a puzzle box, with an automated door giving access to mealworms. A bird solving the puzzle gained access to the food. One bird in each group was shown a relatively inefficient solution to the puzzle. The rest of the group then learned the procedure from the trained individual. In due course, a bird would discover a simpler, more efficient, solution. The speed at which the rest of the group adopted the new approach varied.
Then new untrained birds, immigrants, were introduced to half of the groups. Birds in groups with immigrants accepted the new, more efficient, solutions to puzzles quickly. Those in groups without immigrants were much slower to do so. Immigration, therefore, is a driver of cultural change in great tits. Birds could continue with outdated behaviours, but new blood in the form of population turnover seems to force them to change their ways.
Great tits form flocks in winter when conditions are harsh and birds are under pressure. Embracing new, more efficient, behaviours and discarding older ones is imperative at this time of year. Tits joining a flock play “a role as adopters rather than innovators of efficient variants which out-competed established less effective ones. Turnover might be a general mechanism in the cultural evolution of efficiency”, the researchers conclude.
“Beyond genes, culture offers a secondary inheritance system.” It too is a product of natural selection.
- Michael Chimento et al. Population turnover facilitates cultural selection for efficiency in birds. Current Biology. 2021.