Cockatoos are teaching each other how to open bins

Bin-opening was first observed in 2015 and has since spread to 44 different parts of Sydney. Here’s how it happened.
By Angela Heathcote July 23, 2021 Reading Time: 3 Minutes Print this page

“Wow, what a cockie,” was the first thought Australian Museum ecologist Richard Major had when he first spotted a cockatoo diligently lifting a bin lid and poking around for the good bits. “I knew at that moment that this was a behaviour that was significant and worth monitoring.” 

Seven years after that first observation Richard and an international team of ecologists and animal behaviourists have published a ground-breaking scientific paper about the cockatoo’s bin-lifting behaviour. Declaring that this unique practice is not the result of genetics, but rather passed on through social learning. 

In the scientific world, this is known as animal cultural transmission, and it’s considered to be quite rare and difficult to prove. 

In early 2018, the team of researchers asked Sydney-siders to submit videos and photos of cockatoos in their area opening household bins to scavenge food. The survey was then repeated in 2019, and 500 cockatoos across the suburbs of Sutherland, Helensburgh, and Stanwell Park were marked with small dots of paint. This allowed the scientists to assess who was opening the bins and how they were opening bins.

“We discovered different subcultures,” says Richard. “There were slight variations in the way different groups were opening bins. Birds within one group would open the bins in a similar fashion, while another group from a separate area would use an entirely different method.

“It’s trivial things like whether it walks left when it’s sliding the bin open, and whether it holds the bin lid half open with its foot or beak,” explains Richard, “and because these techniques varied geographically but were similar among close individuals, it’s an indication that opening bins is socially learned.”

Related: Urban bird watchers’ guide to Sydney

(Video credit: Barbara Klump)

On top of this, the behaviour was spreading rapidly throughout Sydney. Since first being observed in 2015, the behaviour has now been recorded by residents from 44 different areas. 

But not all cockies are bin-openers. Fewer than 10 per cent of cockatoos in a flock opened bins while the others would either be watching and learning or ready to swoop on the goods once the deed was done. 

So who exactly is opening the bins? Lead author of the paper and animal behaviorist Barbara Klump says it’s mostly the males. “This could be due to the fact that they are bigger than females and that the bin-opening is physically demanding.”

Hierarchy also comes into play. “There’s a dominance hierarchy in a flock and birds that were higher in that hierarchy were more likely to be bin openers. That’s partially because they have more opportunity and they’re a bit more aggressive. Some would chase other birds off a bin,” says Richard. 

Related: Australia’s five black cockatoos

(Video credit: Barbara Klump)

Whether or not cockies beyond Sydney will master bin-opening too is yet to be seen. Barbara says there’s anecdotal evidence from Victoria, but this hasn’t been formally studied.  

Could other species of bird catch on? 

“It is unlikely that ibis will learn to open bins, they don’t have the equipment – the dexterous foot and beak combination,” says John Martin, an ecologist at Taronga Conservation Society and a co-author of the study. “Other parrots have the equipment, it will be interesting to see if they learn or initiate this behaviour.”

Richard says – when it comes to cockies – people can be separated into two camps: those that will observe this behaviour and admire their intelligence and those who see them as a pest. However, Richard says it’s better that we admire their adaptation to our ever-changing environment. “There’s a commercial bin lock you can now use, so we can adapt to them like they adapt to us.”

John confirmed that more surveys will be conducted in the spring of 2021. For now, Australians can assist with the research by participating in the Big City Birds citizen science program, which aims to shed more light on the lives of our urban birds.