The cockies that bring mayhem and mischief to our valley in winter have left for breeding grounds in the upper Derwent Valley and it’s a relief not to hear their squawking, screaming and general carrying on.
After they arrive in autumn, the cockies raid fruit trees in gardens and also attack wooden roofs, presumably to sharpen their beaks.
But the antics of the hundreds of cockies which roost at night in the Waterworks Reserve from about May to the end of August have nothing on a clan that brings a cocky swagger to the parks of Sydney.
This group of sulphur-crested cockatoos display a remarkable level of intelligence in learning to open wheelie bins and to turn on taps.
This behaviour is considered unique to Australia’s urban environments, and now it is being mapped by ecologists from the University of Sydney and the Max Planck Institute of Ornithology. Sydneysiders are being urged to help document the birds’ behaviour.
Dr Barbara Klump from the Max Planck Institute said they were studying which birds adopted these behaviours and how they learned to do it.
“The really big question is: why are they such good urban adapters?” she says.
Although parrots along with crows are noted for their intelligence – some species within the two families have brain power to rival chimpanzees – the sulphur-crested has so far slipped under the radar of researchers. The prize for the smartest bird goes to African grey parrots which can learn hundreds of human words and use them in context to communicate with their owners.
Dr John Martin, an honorary associate at the University of Sydney, said the study was examining the social hierarchy of flocks, cognitive abilities and information transfer.
Some cockatoos in Sydney have been marked with coloured paint dots to help researchers identify them easily.
“Then we can look at their social interactions,” Dr Martin said. “We’re looking at how the birds might be having a fight, or preening each other, looking at those relationships, and also with respect to their age and if they are a breeding bird.”
Dr Martin acknowledged some people are not impressed by the cockatoos’ nuisance behaviour. Opening a bin might be annoying to residents but understanding how this behaviour evolves and how it persists in a population was interesting from a cognitive perspective.
“They potentially started foraging from overfilled bins and then the birds asked: ‘Can we open closed bins ourselves?’. So it’s quite a leap of intelligence,” he said.
Researchers are keen to work out if the birds are using different techniques in different areas of the country to open the bins.
“If this is also happening in Brisbane or Melbourne, that’s really interesting because it’s quite clearly an example of this behaviour evolving in a different area,” Dr Martin said.
There is no word yet if the researchers plan to extend their research to Tasmania. If they do the residents of the Waterworks Valley might discover their visiting cockies are not bird brains after all.