You’ve heard of trash pandas: trash-raiding raccoons. How about a garbage parrot?
Sulfur-crested cockatoos, which may seem appealing to Americans and Europeans, are everywhere in Sydney’s suburban areas. They have adapted to the human environment, and since they are known to be clever at manipulating objects, it is not entirely surprising that they followed a rich food source. But you could say that the spread of his latest trick, opening the litter box, shuts down social learning and cultural development in animals.
Birds acquire skills not only by imitating others, that is, social learning. But the details of the technique developed differently in different groups as innovation spread, a symbol of animal culture.
Barbara C., a behavioral ecologist at the Max Planck Institute of Animal Behavior in Germany. Clump, and the first author of a Report on cockatoo research in the journal Science, said, “It’s actually quite a complex behavior because it has so many steps.”
Dr. Klump and his colleagues break down the behavior into five moves. First a bird uses its bill to remove the lid from the container. Then, she said, “they open it and then hold it and then they move to one side and then turn it over. And there’s a variation in each of these steps.”
Some birds move left, some right, they step apart or hold their heads differently. This process is similar to the spread and development of human cultural innovations such as language, or animal culture, a classic example of bird song, can vary from region to region within the same species.
Dr. Klump and his colleagues in Germany and Australia plotted the spread of the behavior in Greater Sydney over the course of two years. The behavior became more common, but it did not occur in random places as it might have if different birds were detecting the garbage bin technique on their own. It spread outward from its origin, indicating that cockatoos were learning how to do it from each other.
Cockatoo’s new skill opens up a new resource for birds. This is adaptive cultural evolution, which is spreading at a lightning speed compared to biological evolution. Dr. Klump notes that culture has been called a second inheritance system and applies to both humans and animals, allowing us and them to quickly adapt and change our behavior.
It is impossible to know which bird or birds first developed the garbage bin technique, but apparently a lone cockatoo is not a genius. Over the course of the study, the behavior popped up a second time in a suburb far from the first for the spread by social learning, Dr. Klump said. The technology was re-invented.
Scientists have observed social learning and what they call culture in primates, songbirds and other animals. Different groups of chimpanzees show slightly different patterns of tool use, for example, as did the cockatoo.
Researchers not only observed different techniques in different fields. They marked and observed about 100 cockatoos to better understand individual behavior.
They found that about 30 percent of the birds tried to open the box and about 10 percent were successful. Most of the successful birds were males. Dr. Klump said men were successful because they grow up and are probably better able to cope with the physical demands. Or it could be that they were in a higher position, and would normally have their first access to food.
But what about the birds that were not trying to open the box? Were they simply not smart or big enough? Not necessary, Dr. Klump said, because once the box is open, any cockatoo can join in and forage without doing any work. Maybe, she said, they have a strategy: “This bird can do it—I’ll wait until they open it.” Whether this is true is a matter of future research.
Mark O’Hara of the University of Veterinary Medicine Vienna, who studies the cockatoos of wild goffins in Indonesia, said the study “combines citizen science beautifully with rigorous direct observations.”
He said he is particularly interested in the larger, higher-ranking parrots that are working to exploit the new resource. “In primates,” he said, “lower-ranking individuals will need to find new ways to access food, while stronger dominant individuals can more easily displace and exploit these ‘discoveries’.”
The first parrot species known to open garbage cans was the kea in a park setting in New Zealand. But in that case, Dr. O’Hara said, humans ended cultural development early on.
“It will be interesting to see how the kea may have evolved over time, but unfortunately, the park was not very happy with the raid on the trash and replaced the bin cover.”