Cockatoos and Humans Battle Over Trash Cans in Australia

There's more human-wildlife conflict as habitat is lost.

cockatoo nudges a brick on a trash can
A cockatoo nudges a brick on a trash can.

Barbara Klump

It’s a battle between humans and smart birds … over trash.

Residents in Australia want to toss their garbage and cockatoos would like to eat it. Researchers are studying the curious relationship and the industrious techniques the birds are using to nab their dinner.

“In Southern Sydney, on bin-day, we see cockatoos (attempting to) open bins to get to the food,” lead author Barbara Klump, a behavioral ecologist at the Max Planck Institute of Animal Behavior, tells Treehugger. “It is not as easy for them as it may look, only a small number of birds can actually open it.”

When Klump first saw videos of the techniques the birds used to try to open the garbage cans, she says she found it so unusual and interesting that she had to learn more.

She found that sulphur-crested cockatoos (Cacatua galerita) have come up with innovative ways to pry open cans to get to edible trash. They are particularly motivated by discarded bread.

“The behavior is a 5-step process,” she says. “Birds first pry open the lid, then open it while standing on the rim, they then hold the lid open with their beak and/or foot, walk along the rim, and finally flip the lid over.”

Humans, in return, have developed a range of methods to counteract the crafty birds.

Crafty Birds and Humans

For their work, researchers studied 3,283 garbage bins in four suburbs that had reports of cockatoos opening the containers. For each bin, they recorded whether or not it was protected against the birds in some way. If it was, they considered the method used, the location of the device and what it was made of, and whether or not it was attached to the bin.

They found people tried all sorts of things to keep the birds away. They placed rubber snakes, bricks, or stones on the lids, strapped water bottles to the top, tied ropes to keep the lid from flipping, wedged in items to block the hinges from moving, and even tried commercially available cockatoo locks, made just for trash cans.

“We found more than 50 different ways in which people protect their bins,” Klump says. “They range from putting something heavy on the lid to make it difficult or impossible for cockatoos to open, to putting something (sneakers/sticks/empty milk bottles) between the hinges to prevent flipping of the lid.”

When cockatoos figured out one method, people switched and tried another.

Researchers found that cockatoos easily solved less-tricky devices like rocks or bins but were unable to open bins that were most protected, such as with full water bottles strapped to the top or sneakers jammed against the hinges so they couldn’t open.

“When I first started investigating the bin-opening behavior by cockatoos, I was really surprised and impressed by the variety of methods that humans have come up with to stop cockatoos from opening the bins,” says Klump. “The interplay between the cockatoos and the humans really intrigues me.”  

The results of the study were published in the journal Current Biology.

Social Learning for Everyone

Developing innovative ways to forage can lead to human-wildlife conflicts. There are elephants that raid crops, for example, and long-tailed macaques that steal items from people, then trade them back for food.

But it’s not just social learning for the cockatoos in Australia; it’s also social learning for humans.

“People come up with new protection methods on their own, but a lot of people actually learn it from their neighbors or people on their street, so they get their inspiration from someone else,” Klump says.

As cities grow and animal habitat is lost, researchers expect to see more of these interactions between humans and wild animals.

Klump says. “I'm hoping that there will be a better understanding and more tolerance for the animals that we share our lives with.”

View Article Sources
  1. lead author Barbara Klump, a behavioral ecologist at the Max Planck Institute of Animal Behavior

  2. klump, Barbara C., et al. "Is Bin-Opening in Cockatoos Leading to An Innovation Arms Race with Humans?" Current Biology, vol. 32, no.17, 2022. doi:10.1016/j.cub.2022.08.008