In the suburbs of Sydney, Australia, a battle is raging between the beast and the bird.
In one corner, Homo sapiens, an evolutionary success story with opposing thumbs and big brains that has taken over the world. In the other corner, Cacatua galerita — either, the Sulphur-crested Cockatoo, a yellow-crested parrot with an exhausting screech. The two sides have spent the last few years locked in a suburban war, striving to take control of the garbage kingdom.
Wild “cockies,” as they are known in Australia, have learned to open residents’ bins with their beaks to gain access to sweet food discarded by humans. That has made them particularly interesting to behavioral scientists.
The intriguing flyers were the subject of a study in the journal Science in July 2021 Led by Barbara Klump, a behavioral ecologist at the Max Planck Institute for Animal Behavior in Germany. Klump and her collaborators showed that young cockatoos were being armed with the ability to open Australian “wheelie” containers and search for food through “social learning.” They were basically copying other cockatiels for discarded toast and last week’s takeout (which you ordered way too much).
Now Klump and his collaborators are back with a new study, published in the journal Current Biology on September 12, recording the unique interactions between the two sides of the garbage war. They point out that as the smug have become more innovative when it comes to opening containers, residents have also been learning, and teaching each other, how to protect their containers with increasingly effective measures.
The team counted 3,283 bins in four suburbs where cockatoos had previously been recorded opening bins. In short, the team walked around and studied the containers, checking to see if the human owners had put up protection. They write that the levels varied between 0% and 50% in the suburbs.
Those using protection against cockatoos were evaluated based on different levels ranging from no alteration to the container (ie, placing a rubber snake on the lid) to a fixed alteration, such as a weight. The team was able to show that the cockies are not afraid of rubber snakes and happily open those containers. They have also been shown to knock over objects, such as bricks, to open the dumpster safe. However, they have yet to crack the more difficult levels of the dumpster contraptions, such as “shoes on the hinge.”
Interestingly, the team studied how these protective measures were implemented in different suburbs. They found that protected containers were “geographically more varied by protection status than would be expected if protection were randomly distributed.” They also found that bins close to one another on a street were more likely to use similar protection methods than those that were close but out of sight.
Basically, they were seeing a pattern of protection that suggested the human side of the garbage war was strategizing defenses.
“People create new methods of protection on their own, but a lot of people actually learn them from their neighbors or people down the street, so they take inspiration from someone else,” Klump said in a news release.
Previous surveys suggested that about two-thirds of those surveyed (a group of 172 people from 51 suburbs) had learned their protection method from a neighbor or people on their street.
Another subset of respondents also changed the level of their protection based on the behavior of the cocky ones. The authors highlight a specific example where a human litter advocate was using bricks on the lid of his dumpster. The cocky ones, says the respondent, got too smart and started sticking a stick through the hinge of their container to prevent the flap from lifting all the way. As you can see in the main image, a cockatoo makes quick work of a brick. But below, you can see a fight with the stick.
Kleptocockatoos haven’t thought of these high-level protection measures yet, but they may not stay that way forever. If some of the winged warriors begin to evade human defenses, it has already been shown that others will follow. And will that continue to drive innovation from both beasts and birds? Potentially! But the research team writes that they need to better understand the mechanisms underlying learning behaviors and identify whether cockatoos can work out higher-level protective measures.
The study is ongoing, and citizen science has been key in revealing this arms race of innovation. Without the help of respondents across Australia, litter theft may never have been fully understood. If you’re in Sydney and discover that cockatoos are opening the bins in your area, or even if you’re somewhere else in Australia with Sulphur-crested Cockatoos and you’re No Seeing this behavior, you must respond to the 2022 survey using this google form.