BUDGIE BRILLIANC E
Perfect conditions in outback Australia have attracted thousands of budgerigars, creating one of nature’s most awe-inspiring aerial spectacles.
THE DESERT IS quiet for now, except for the sounds of our boots crunching over dry grass and padding across thick red dust as we approach a waterhole outside Alice Springs that only locals know about. It’s a cold early August morning and we’ve ventured here to see one of Central Australia’s most spectacular phenomena: a murmuration – an immense flock – of budgerigars. We settle by the water’s edge in the pre-dawn stillness and wait in silence for the birds’ first trills to emanate from somewhere unseen. Soon 20 budgies fly overhead, followed by group upon group swelling the flock. Their wingbeats pound as they sweep overhead, now in bands of hundreds, and their constant chirping creates a powerful wall of sound.
Within minutes, thousands of budgies are twisting and turning in unison, forming a moving sea of silhouetted bodies over the landscape as they swoop in turn to drink from the waterhole. Their stunning acrobatic display is amplified by the morning light; as the sun catches wings, their backlit forms flare up in brilliant flashes of green and yellow. Colour ripples through the clouds of birds as they change direction, dancing through the sky.
At its peak, this murmuration comprises hundreds of thousands of birds, their pounding wingbeats sounding like a train whooshing along its tracks and their high-pitched chirping rising to a relentless cacophony that fills the desert. I sit with my mates in silence, witnessing the marvel and feeling the birds’ movements vibrate through my body.
I’VE PHOTOGRAPHED murmurations of budgies in the outback before, but this is one of the most impressive. Such large numbers are unusual; flocks normally range from three to 100 birds, but conditions this year have been particularly favourable for budgies. The movements of these small green-and-yellow parrots are nomadic and highly migratory, motivated largely by food availability – grasses setting seed across arid zone savannahs and open woodlands, including mallee and mulga forests. Budgies occur naturally throughout most of Australia’s interior west of the Great Dividing Range. They’re not found in Tasmania or the coastal areas of eastern, northern, or south-western Australia.
In the wild, budgies feed almost exclusively on grass seeds, particularly of tussock grasses, and on the seeds, grains and nuts of native herbaceous plants. It’s a very low-moisture diet, so budgies need to drink fresh water daily and to do this they typically visit waterholes each morning.
Th is boom-bust species ha s recently experienced population explosions throughout interior Australia, following widespread rain that led to the setting of seeds across thousands of arid hectares. In the Red Centre, the winter months saw dams and waterholes transformed at dawn each day by huge flocks streaming in and out for hours. “We’ve seen several key environmental factors come together to set the stage for this type of event,” explains zoologist and local birdwatcher Mark Carter. “Good conditions began in 2019 with rainfall on the eastern side of the Simpson Desert and in western New South Wales, and then last year, rainfall built up through the Channel Country.” Each rain event produced more grain, and budgie numbers grew.
Last year, Central Australia recorded one of its coolest and wettest summers in a decade after three years of drought. Following a string of extremely hot summers, temperatures cooled and a handful of well-spaced rain
events offered reprieve; parched riverbeds filled, native grasses replenished, and the landscape began to burst with life.
“Budgies go wherever conditions are best,” Mark says. Numbers of resident species, such as the rufous-crowned emuwren, declined during the drought, and nomadic species, such as budgies, simply left. Not being fixed to a defined territory, combined with a suite of evolutionary adaptations for efficient movement across distances, means individuals can cover vast expanses to find food and water. Once conditions improved, the birds returned. “Significant rain events here in March coincided with grain developing, and we ended up with huge numbers returning,” Mark says.
Other local factors also helped. For example, low cattle numbers following the drought have meant food for budgies has been more abundant. “By having less cattle on the land, the grasses were able to seed, so there was far more biomass available for seed-eating birds,” Mark explains. “If all that resource in the grass went into cattle, our budgies would have missed out.”
SEED-EATING BIRDS readily upcycle the widely dispersed resources they consume. Spending most of the day feeding in small flocks of 20–30 birds, budgies consume seeds gathered from vast areas. Like most Australian parrots, they need tree hollows to nest. Each night, as they nest and roost in the upper branches of gnarled river red gums and coolabahs, they drop dung. In years such as this, when every suitable tree is covered in budgies, they transfer vast amounts of nutrients retrieved from the broader landscape to the ground beneath these nesting sites. A type of coevolution seems to have occurred between the birds and the eucalypts: individual trees that produce more hollows are used by more birds, resulting in more fertilising dung being deposited.
“Where they nest, they deposit a big carpet of white dung on the ground, under the coolabah trees, and the amount of nutrient that’s giving the plants is huge,” Mark comments. “The budgies harvest all this goodness that is dispersed right across the landscape, and bring it to these trees. On a landscape level, that’s a huge benefit.” Other species also profit from the budgie influx.
“It’s pretty great for everything that eats budgies,” Mark says. In particular, the flocks attract birds of prey, including one of the world’s rarest, the grey falcon – a specialist budgie killer. “They’ve been doing it tough because of the drought,” Mark says, “but suddenly more are being seen in Central Australia than we’ve seen in the past decade.”
Birds of prey dive-bomb budgies as they seek water, which is why they flock as they approach waterholes. It’s a safety-in-numbers strategy: the flock reacts to aerial attacks with swift and erratic movements, confusing the predatory birds, much as fish schools coordinate movements to escape predators.
THROUGHOUT AUGUST I witnessed many thunderous clouds of budgies create hypnotic patterns in the sky as tens of thousands of birds twisted and turned in unison above the dams and waterholes around Alice Springs. It’s now late winter and budgie numbers in Central Australia are still exceptionally high.“There’s so much food here that the birds are still breeding, they’re still nesting in the trees, and it’s still manic,” Mark says. “There are still humungous numbers of birds here.”
When the food begins dwindling so will the birds. “Once the seed starts to run out…they’ll start moving to where there’s been more seed production. The grasses in the Tanami Desert are still very productive – there’s still a lot of groundwater up there – so my guess is they’ll head there. If I were a budgie, I’d be thinking about that as my next step.”
But while the birds are still abundant here, both Mark and I will continue enjoying one of Central Australia’s great spectacles. And once the birds move on, we’ll relish seeing the ripple effects of their presence on the landscape.