Foxes, raccoons, crows – many animals like to look for food in garbage cans. The cockatoo in Australia even cleverly opens garbage cans – which local residents are trying to prevent with more and more new measures.
Garbage cans have become a bone of contention between the cockatoo and the people of Sydney. Sulfur-crested cockatoos have developed a sophisticated technique for opening the lids of plastic garbage cans with the beak and feet, reports a research team led by Barbara Klump of the Institute of Animal Behavior. Max Planck in Konstanz in the journal Current Biology. As they spread trash around residential neighborhoods searching bins, residents try to keep the birds away by using more and more tricks.
“As soon as the cockatoo opens the trash can, the other cockatoos will come and try to eat something tasty,” explains Klump. “They like bread very much.” It is not known which resourceful bird first got the idea – but it is clear that the behavior quickly found imitators: in 2018, according to a survey of local residents, the trick was observed in only three areas. At the end of 2019, birds were catching food from garbage bins in 44 areas in this way.
Residents resort to drastic measures
However, local residents reacted and came up with new methods to prevent the covers from opening. In the survey, 61 percent of around 170 participants said they resorted to increasingly drastic measures over time – as the birds, in turn, came up with new ideas each time. Rubber mannequins of snakes placed on baskets soon stopped frightening the cockatoo, and even heavy objects such as stones over the centuries did not scare the birds away from their target for long.
“The stones seemed to work for a while, but the cockatoo has gotten too clever,” said a local resident. The birds tossed their heads or beaks over the edge of the lid, thus freeing themselves again.
“Kakadu’s not only learn socially how to open garbage cans, but local residents also learn socially how to protect their trash cans from cockatoos,” explains Klump. “Residents come up with new methods of protection themselves, but many learn from their neighbors or the people on their street, so they get inspiration from someone else.”
About two-thirds of the respondents sought orientation from their neighbors. The same was the case with the cockatoo, where barrier-breaking techniques also spread to local populations.
The newest – and still effective – human idea: shoes or plastic bottles are placed on two hinges so that the lids can no longer be opened. Just in case, some residents also attached heavy objects, such as filled water bottles, to the lids with cable ties. Seems to be working – at least for now.
There are always similar races between wild animals and humans, explains the Klump group. An example is the elephants in Africa that devastate the fields and always overcome new conservation measures, another macaque in Asia that steals things from people and gives them only for food. (dpa)