Cockatoos blow the lid off garbage bins, and others learn by example

Researchers say sulphur-crested cockatoos (cacatua galerita) are a “large-brained, long-lived, and highly social parrot native to eastern Australia.” Increasingly common in cities, they are the subject of a new study published in Science magazine.

A team of international scientists have proven that cockatoos “learn from each other a unique skill – lifting garbage bin lids to gather food.” According to a news release, the scientists say that cockatoos “spread this novel behaviour through social learning.”

The research led by Barbara Klump and Lucy Aplin (Max Planck Institute of Animal Behavior), along with John Martin (Taronga Conservation Society) and Richard Major (Australian Museum), has “shown that this behaviour by cockatoos is actually learnt, rather than a result of genetics.“ 

It turns out that some cockatoos have figured out how to open trash bins and feed on the contents within (video). Other cockatoos observing this behaviour have picked up on it, and the behaviour has spread from an origin point.

On the other hand, the researchers say that in some Australian suburbs too far away for the behaviour to be observed and learned, other cockatoos have figured the trash bin scenario by themselves and practice it separately, with slight differences in their actions than the initial group of cockatoos.

“Children are masters of social learning. From an early age, they copy skills from other children and adults. However, compared to humans, there are few known examples of animals learning from each other,” Klump said.

“Demonstrating that food scavenging behaviour is not due to genetics is a challenge,” Klump added.

It turns out that it all started with Richard Major sharing a video with senior author Lucy Aplin a few years ago. In the video, a cockatoo was seen opening a closed garbage bin using its beak and foot to lift the heavy lid, then walking along the side to flip it over to reach leftovers by Australian residents.

At the time, Aplin was a researcher at Oxford University (and is now at the Max Planck Institute of Animal Behavior in Germany). She and Klump found the footage very compelling.

"It was so exciting to observe such an ingenious and innovative way to access a food resource, we knew immediately that we had to systematically study this unique foraging behaviour,” Klump said.

According to the news release, Major, a Senior Principal Research Scientist at the Australian Museum Research Institute, “has spent more than 20 years studying Australian bird species such as the noisy minor, the infamous ‘bin-chicken’ ibis and cockatoos.“

“Like many Australian birds, sulphur-crested cockatoos are loud and aggressive and often act like a pack of galahs. But they are also incredibly smart, persistent and have adapted brilliantly to living with humans,” Major said.

A Research Scientist at Taronga Conservation Society, who has worked alongside Major on many urban bird projects, John Martin went over how the research was carried out: “Australian garbage bins have a uniform design across the country, and sulphur-crested cockatoos are common across the entire east coast. The first thing we wanted to find out is if cockatoos open bins everywhere.”

The researchers have collected data from suburban residents, with a large-scale 20 community science survey to map this behaviour across the Sydney and Wollongong regions, “with direct observations at multiple sites to identify possible individual or site-level differences, whether, where, and when they had observed cockatoos opening lids of household bins.”

They collected 1396 reports by 1322 participants across 478 suburbs, of which 338 reports from 44 suburbs described bin-opening, the authors write. They point out that in almost all observed cases (93.3%) multiple cockatoos were present, “highlighting cockatoos’ ample opportunity to observe bin-opening.” They add that “in 88.8% of cases, birds opened general waste bins (identifiable by red lids).”

According to the news release, further analysis of the survey results showed that “the behaviour reached neighbouring districts more quickly than districts further away, indicating that the new behaviour wasn't popping up randomly across Sydney.”

"These results show the animals really learned the behaviour from other cockatoos in their vicinity," Klump said. 

The researchers marked about 500 birds with non-toxic paint at three locations to be able to identify individual birds so that they could follow which birds could open bins. They found out that about 10 percent were able to do so, “most of which were males.” The remaining birds waited until the ‘pioneers’ opened the garbage bins to scavenge for food.

According to the news release, “There was one exception, however: in late 2018, a cockatoo in northern Sydney reinvented the scavenging technique itself. Birds in neighbouring districts then copied the behaviour.”

“We observed that the birds do not open the garbage bins in the same way, but rather used different opening techniques in different suburbs, suggesting that the behaviour is learned by observing others,” Klump said.

According to the scientists, this was an “emergence of regional subcultures.”

"By studying this behaviour with the help of local residents, we are uncovering the unique and complex cultures of their neighbourhood birds,” Klump said.

Thumbnail photo: A sulphur-crested cockatoo opening the lid of a household waste bin. Barbara Klump/ Max Planck Institute of Animal Behavior

Headline photo: A sulphur-crested cockatoo opening the lid of a household waste bin using one of many different opening techniques. This bird holds the lid with the bill and its left foot. A second bird is observing it closely. Barbara Klump/ Max Planck Institute of Animal Behavior