Round about this time of year in tree hollows all over Australia, sulphur-crested cockatoo chicks are hatching.
But what do you know about this iconic native bird?
Did you know they're "left-handed", can live for 100 years, or that they pick bindi-eyes out of your lawn before the weeds turn prickly?
Love them or hate them, cockatoos as a group evolved 95 million years ago on the ancient continent of Gondwana and are some of the smartest birds around.
And they've made their home in our big cities as well as in the bush.
So why are they so clever and what are they capable of?
The term "clever cockie" doesn't come out of nowhere.
"They're comparable to a chimpanzee in intelligence," says bird expert Gisela Kaplan of the University of New England.
This is because they pack a lot of neurons into their bird brains, which are organised in a way that enables complex processing.
This "lateralisation" results in a preference for using one foot over another — and sulphur-crested cockatoos are "left-handed".
"They can balance on one foot while they eat with the other foot," Professor Kaplan says.
And they are able to learn all manner of new things that help them survive in different environments, like the city.
In fact sulphur-crested cockatoos are one of the key species targeted in the Big City Birds citizen science project, which is studying just how clever birds can be at adapting to living in the city.
For example, some cockatoos have learnt how to open wheelie-bins to look for food and turn bubblers on when they're thirsty.
It appears the birds learn these skills by copying other birds, and, if research with another species of cockatoo is anything to go by, even a lock or two won't stop a cockatoo.
The Big City Birds project is asking citizen scientists to report all aspects of bird behaviour, from play and aggression to bin-opening and other unusual activities via an Android or iOS app or its website.
What do they eat?
As far as we know, wild sulphur-crested cockatoos mainly rely on berries, seeds, nuts and roots — although researchers are keen to get your observations on what they are eating in the city.
Interestingly, when you see them hanging around on the lawn, they might even be doing you a favour because they eat bindi-eyes before they become prickly, says John Martin, of the Big City Bird project.
They will also eat food from humans, although it's not necessarily good for them.
Sometimes you'll see a bunch of birds busily biting off branches and leaves from a tree but dropping them on the ground.
"They end up tip-pruning a whole bloody tree," Dr Martin says.
This isn't about getting food but more likely helping them to keep their beak trimmed and sharp.
Why do they cause so much damage?
It's their powerful beak — capable of doing things like cracking macadamia nuts — that can give the birds a bad reputation.
As loveable as they can be to those who admire their cleverness, farmers can find them devastating.
And while as a native species they are supposed to be protected, sometimes they are shot. This is illegal unless people have a special permit to control them as pests.
As anyone who has seen a cockie strip wood off their deck will tell you, the birds also damage buildings — they once did $50,000 worth of damage to the roof of the National Herbarium of New South Wales and, in another case, $80,000 worth of damage to broadband network cables.
Without being inside the mind of a sulphur-crested cockatoo, it's not clear why they do this sort of thing.
They might be sharpening their beak — but that seems like a lot of sharpening!
"It could just be they've got a bad attitude," says Dr Martin, adding it might be boredom or playfulness, and it might only be some individuals that are guilty of this behaviour.
He says keeping them away involves a bit of persistence — you can try spraying them with water, putting a taut wire above railings, or using bird-safe netting to exclude them from areas.
Professor Kaplan says some of the damage caused by cockatoos may be a result of humans having gotten rid of so much of the birds' natural habitat.
Why are they so noisy?
If there's one thing sulphur-crested cockatoos are known for, it's their loud, raucous screeching as they zoom overhead: it can be quite deafening when they're in big numbers.
"The worst I ever heard was a flock of 150 that sounded like a freight train. It was frightening," Professor Kaplan says.
She says this behaviour evolved as a way of terrifying away would-be predators, even though there are few of those left around these days.
They have other shorter calls for communication, she adds.
Professor Kaplan says cockatoos also communicate by changing the shape of their yellow crest and combining this with different body postures to indicate alarm, availability or something lighter.
For example, for 15 years she's taken care of a cockatoo called Pumpkin who can no longer fly due to injury.
And she knows when Pumpkin is feeling playful: "His crest goes up completely and his head starts bobbing up and down and sideways."
What do we know about their society?
Research that involved tagging individual sulphur-crested cockatoos has given scientists some interesting insights into cockie society in one of Australia's biggest cities.
Dr Martin and colleagues collected tens of thousands of reports from citizen scientists over eight years to map the movement of individual birds in the Sydney region.
It's shown flocks of about 50 to 100 tend to spend all their time — whether sleeping or feeding — in the same small 5-square-kilometre area.
"I've been blown away by how little they move," he says.
"They've got a tight network, like a township of humans."
And he says, just like in a township, the birds hang out in various combinations, including gangs of 5 to 20 birds who are best mates.
Sometimes multiple flocks will converge on a particular area for a festival of feeding.
Tracking has also found cockies are very egalitarian when it comes to parenting, with each long-term partner taking turns to stay with the eggs and the chicks, while the other goes out foraging, Dr Martin says.
You can only tell the sex of the bird by the colour of the eyes: males have a solid black iris, females a red iris.
You're not like to see baby cockatoos because they don't emerge from the nest until they're bigger. But if you listen carefully you might hear them — they make a droning 'arrrrrrrr' call when they're begging for food and a quick staccato squeak when they're fed.
When they do grow up, cockies can live for a long time — perhaps 40 years in the wild to over 100-odd years in captivity.
In fact, one centenarian cockie even got a letter from the Queen.