We’re In The Middle Of An Arms Race With Cockatoos For Our Wheelie Bins

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In the battle for the hotly contested territorial control of our wheelie bins on bin night, who will prevail: humans or cockatoos?

There’s a new study about how sulphur-crested cockatoos have learned how to get into our rubbish bins. The same researchers had done a study before about how cockatoos learned their bin-opening skills from each other. They found that bin-opening behaviour was spreading out from suburbs where it was already happening, not randomly popping up. This meant it was more likely that cockatoos were learning from each other rather than coming up with it on their own in different places.

For their new study, the researchers turned their attention to human behaviour.

How Humans Defend Their Wheelie Bins

The tricky part about defending our bins from these yellow-crested thieves is that they still need to be opened easily for the rubbish truck. 

Something needs to weigh down the lid enough to prevent cockatoos from getting in but not too much to stop it opening for the truck. These are the four examples you can do to keep them out in order of effectiveness, as described by the study.

Four strategies seen by the researchers of this study

The least effective way to stop a cockatoo is placing a fake snake on the lid to try and scare the birdies away, which doesn’t work too well because it can be moved too easily. 

Next is a brick, that cockatoos have also learned to simply yeet off. 

People have even tried attaching objects to the hinge of their bins, that rubbish collectors can remove before tipping the bin — like a pair of shoes. 

And finally there’s the zip-tied water bottles to weigh the lid down, that can easily swing open for the truck.

These clever defences were recorded by the researchers as part of their census of over 3000 bins across Sydney and Wollongong. What they actually looked out for bins was based on a preliminary online survey to find out where these parrot pirates pillaged the most.

The researchers coined it an “interspecies innovation arms race”. And it actually happens a lot across the animal kingdom.

Examples Of Other Arms Races

In evolutionary biology, this kind of back and forth can change physical and behavioural traits as two parties keep battling it out. It’s called an evolutionary arms race and there are some really wild examples.

One of the most well known examples is with bats and moths. First, bats developed echolocation to find moths even when it’s completely dark. Moths with ears were able to hear these tracking calls and avoid being eaten, as well as ones that could pull Top Gun evasive manoeuvres and dodge any bat attacks. Moths that had this evolutionary advantage were more likely to survive: the species essentially evolved ears that were best suited to escaping bats.

The idea that moth ears evolved specifically because of this batty behaviour is supported by the fact that they’re most sensitive to the same frequencies used by the bat species that hunt them. Some bats have then evolved stealth echolocation by using clicks and sounds that moths can’t hear. Moths have since developed their own ultrasonic clicks to use defensively. And on it goes.

What Lies Ahead For Our Bins?

While this arms race we’re currently facing on bin night with these cockatoos isn’t necessarily changing our evolution, it is, as the study called it, an ‘innovation arms race’.

Maybe it could lead to developing new bins with built-in bird protection. But cockatoos could then develop some kind of way to unlock it, since they’re damn good puzzle solvers.

Until then, it might be time to find some zip ties and water bottles.