A fast-paced arms race has arisen in Australia as humans attempt to deter cunning cockatoos
ARMS RACES DON’T ALWAYS LEAD to mutually-assured destruction. If new research on an ongoing conflict between cockatoos and human householders in Australia is anything to go by, they might just result in one party missing a meal or the other becoming mildly irritated.
Sulphur-crested cockatoos were first spotted raiding Sydney’s domestic rubbish bins for food in 2018. “We had reports of cockatoos opening bins in three suburbs,” says Barbara Klump, who led the work from Germany’s Max Planck Institute of Animal Behavior. “By the end of 2019, it was in 44 suburbs, so we could see that the birds were learning it from each other.”
And it’s not just the cockatoos that are adapting to circumstances. “People started to protect their bins, because the birds do make a lot of mess, throwing out everything they don’t want to eat,” says Klump.
The team’s latest study, published in Current Biology, documents 52 countermeasures employed by householders to keep cockatoos out while making sure the lid still opens when the refuse collectors turn the bin upside-down. These include placing bricks on the lid to weigh it down, which was effective until the parrots learned to push them off. Tied-down water bottles and training shoes wedged behind the hinge of the lid have so far proved more effective.
“It’s a cultural behaviour on both sides, so it’s clearly faster than evolutionary arms races, which play out over really, really long timescales,” says Klump.
“Culture enables animals to adapt much faster, especially for a long-lived species such as a cockatoo, which is unable to adapt on a genetic level to a rapidly changing environment such as a city.”
Klump is reticent to predict whether the birds or humans will ultimately prevail. “It’s possible that humans will come up with something that the cockatoos are unable to solve,” she says.
But then again, perhaps the birds have more incentive. “Getting one large piece of bread might offset hours of foraging elsewhere. For most people, it’s just a bit annoying.”
Behavioural ecologist Barbara Klump