A Sydney scientist noticed a sulfur-crested bird opening his trash can a few years back. Richard Major, an ornithologist, was amazed by Richard’s ingenuity.
It is quite an accomplishment for birds to grab a bin lid with their beak and then pry it open. Then they shuffle along the edge of the bin until the lid falls backwards, revealing tasty trash treasures.
Major was intrigued and teamed up to German researchers to find out how many cockatoos had learned the trick. They found that three Sydney suburbs had successfully mastered this new foraging technique in a survey of residents. Birds were now lifting bins in 44 suburbs by the end of 2019.
Major, who is based at The Australian Museum, said that “From three suburbs in two years to 44 in two years” is an impressive spread.
Next, the researchers wanted to know if the cockatoos had figured this out themselves or if they were copying the strategies of more experienced birds. And their research published Thursday in the journal Science concluded the birds mostly learned by watching their peers.
It wasn’t just a random phenomenon. Major said that it started in the southern suburbs, and spread outwards. It was essentially a popular dance move.
Scientists have also documented social learning in birds. One classic case involves small birds called blue tits that learned to puncture foil lids of milk bottles in the United Kingdom starting in the 1920s — a crafty move, though less complex and physically demanding than opening trash bins.
Lucy Aplin, a Cognitive Ecologist at Max Planck Institute of Animal Behavioral, Germany, and coauthor of the study, stated that it was a unique opportunity to observe a “cultural trend” in the wild or in the suburbs. She said, “This is the scientist’s dream.”
The team conducted research on trash collection day in suburban Sydney during summer 2019. Barbara Klump, Max Planck Institute behavioral ecologist, drove around the area and recorded cockatoos landing in bins as garbage trucks moved down their tracks. She took 160 videos of the victorious attempts, although not all cockatoos were successful in opening them.
Klump discovered that the majority of birds who opened bins were males. Males are more likely to open them than females. The birds who mastered this trick were also more dominant in social hierarchies.
She said that this suggests that people with more social connections have greater opportunities to learn new behaviors and observe them.
