The duel of the decibels – the chorus at dusk when birds try to outdo each other to dominate the air waves as light fades – was particularly vocal one mid-winter evening.
The clinking of currawong, the caw of raven and the trilling of new Holland honeyeater was in competition with another, alien sound.
As I walked the streets of South Hobart, I had forgotten that the Dark Mofo winter festival was about to start, even though the night before I had seen city buildings and the Tasman Bridge already bathed in the festival’s signature red light.
A feature of the 2017 festival had been billed the Siren Song, in which at dawn and dusk unconventional sounds would be broadcast across the city from 450 public address speakers placed atop buildings around the waterfront.
According to the pre-festival blurb, what I can only describe as the sonic version of installation art would be heard from up to two kilometres away, and here I was, double that distance, being bombarded by sound on two fronts. The birds, particularly the forest ravens for some reason, were responding in kind. It was surreal and unnerving.
The festival organisers described Siren Song as exploring “sound as an expression of patriarchal power and authoritarian control … and in turn, how sonic tools used to control and communicate might give voice to beauty and abstraction”.
For me, its timing at dawn and dusk over 10 days tapped into something far deeper than a celebration of sound in all its forms.
The Dark Mofo festival delves into centuries-old winter solstice rituals, exploring the links between ancient and contemporary mythology, humans and nature, religious and secular traditions, darkness and light, and birth, death and renewal.
Humans claim such rituals as their own, but the division of light and dark has been recognised since long before Homo sapiens entered the frame.
The dawn and dusk chorus is nature’s clock, telling the creatures of the wild when to wake and when to sleep, although for nocturnal creatures the sequence is reversed.
With the parameters of day and night cemented in their genes, birds sing loudly at dawn to re-establish bonds and declare territories. And at dusk, they call each other to night roosts, often gathering together for safety in numbers. At no other time of the day are they so vocal.
Birdsong is so important, so vital to birds, that those living in our cities across the globe have been found to be moderating their songs to take into account the loud sounds of the human world, particularly motor traffic.
Blue and great tits in European cities, for instance, sing louder than their counterparts in the country, as I have discovered myself in London.
Birds that use mimicry to enhance their repertoires are also increasingly using sounds from the human world, with lyrebirds now mimicking chain-saws.
I suspect, though, the birds of South Hobart were pleased to welcome the relative silence when Dark Mofo was over and were cocking their ears in a different direction.