I grew up surrounded by birds, and especially lots of parrots. My birdwatching-filled boyhood in Gippsland had many wondrous moments watching rosellas and king parrots slashing through the air with their varying and gobsmacking liveries of bright reds, blues and greens. In the paddocks, loud clouds of white cockatoos screeched above me. Over the forests, black cockatoos wailed as they flew slowly past on their long, pterodactyl-like wings.

Like its larger relatives, the budgerigar was there – but only in neat little cages in the lounge rooms of some of my quieter relatives. These house-budgies seemed to mirror the personalities of their owners: I thought they were mild creatures devoid of much personality. Even their colours had been carefully faded by breeding to pastel blues, washed-out yellows and pale greens. It wasn’t until later in life that I began to see the budgerigars’ true beauty as I travelled the outback and saw them wild and free – which cured me of my disdain for them.

I found them everywhere in the dry country. They lined the rims of the rock pools on the edge of the Tanami desert, flaring up and down from the water’s edge nervously, watching for predators. They swirled around in chattering groups as falcons real or imagined flew overhead. They poked their little flat-beaked faces out of the hollows of old ghost gums at Uluru, each chittering quietly to a mate sitting nearby. They zoomed in small flocks out of the grassy flats in the mulga around Alice Springs. Along the Cooper in the Channel Country, hundreds sat like elegant lime-green fruit, scattered through the washed-out blue-grey foliage of the coolabah trees.

Budgerigars have carved out an existence in some of the world’s biggest, toughest and most changeable environments.

In the bush, these birds are extraordinarily crowd-loving, sociable and gregarious, utterly different from the caged budgies of my youth. I recall coming over a rise on to the flood plain of the Georgina River in western Queensland after big rains had hit several weeks before to the north in the Gulf country.

Hundreds of thousands of hectares of the flood plain had received a massive, benevolent flood that had soaked in slowly. Vast fields of green native grasslands had matured, then filled with grain.

From my view I was surprised to see billowing clouds of smoke coming from here and there across the plains. It made no sense as the grass was still partly green, and unlikely to yet carry any fire. The smoke swirled and curled strangely in the distance until I realised that each cloud was not smoke but a single vast murmuration of budgerigars. There were tens of thousands in each individual flock, moving like vast shape-shifting schools of little fish through the sky. They had bred up on the productive plains and were now organising to move on.

I no longer disdain the domestic caged budgies I occasionally meet. I’m now in awe of their ability to adapt from huge flocks in an outback desert to a solitary pet in a suburban apartment. Mostly, though, I’ve come to see them as a particular symbol of Australia. They’re especially adapted to the boom and bust of the outback, wandering over the continent, chasing the occasional rains that make the outback grasses grow and produce the billions of little grain seeds on which the budgies depend. They move in to breed ferociously until the seeds run out and the dry times return. Then they flock and fly, looking for the next boom locale or retreating to the coastal bushlands to sit out the drought.

As Australians, it’s easy for us to overlook that on a now very crowded planet our outback spaces are something rare and special. We have huge landscapes where the bush remains uncleared, where rivers still flow freely, and where the wildlife roams across the country over vast distances, as it always has. This neat little bird lives there too, carving out a life of abundance in some of the world’s biggest, toughest and most changeable environments.

These flying green gems of the outback are the iconic Australian bird. I hope they get their deserved place as number 1 for all Australians.

• Dr Barry Traill is director of the Pew Charitable Trusts’ Australian program