Spying the enemy on the wing

THE symphony of spring birdsong, the music of the woods, was in full flight as I went in search of the last of the summer migrants to arrive, the satin flycatcher.

Its song, or at least the tinny, chattering contact call it first makes when it arrives from the far north of Australia, belies the sheer beauty of the species, its plumage painted in the shimmering hue of midnight blue on the head and back, with a silver underside.

I listened for the satin flycatcher but something else, an alien sound, was on the air; buzzing, loud and insistent, far-carrying, rising and falling.

I was about to have my first encounter with something recently arrived like the migratory birds in the glades and woods surrounding the Waterworks Reserve in South Hobart — a drone.

I had heard much of drones in recent years, of pizzas from Dominos and books from Amazon being delivered by such technology, of a drone hitting a plane climbing from London’s Heathrow Airport, of drones becoming weapons of war in the Middle East.

But I had not seen one and here I was watching one in action, climbing, hovering and dashing across the water of the reserve’s twin lakes.

There in a small parking spot near a barbecue site was a young man with controller in hand, steering the drone on its zigzag journey. I was annoyed to say the least.

Birdwatchers, and all those who spend time in the wild, have a thing about “noise pollution”. The quiet is why they go to far-flung places, to escape cars and planes. They rail against helicopters that intrude on such places.

Although cars intrude on the Waterworks Reserve, and also the noise of an occasional plane flying overhead (South Hobart is not on the commercial aircraft flight path), it remains a place of peace and quiet, and a place to hear and learn of melodies and the refrains of our birds.

On this day, such songs were drowned out by the drone. Even more annoying and concerning was that it was invading the airspace of welcome swallows, which each summer hunt insects over the reserve’s lakes and use one of the barbecue huts as a summer home to rear young.

I was confronted with a dilemma. The first urge was to go to the young man with the controller and confront him, to say he was destroying my day, to say nothing of that of the bird’s. But he could say he had as much right to fly his drone as I had to drive my car in the reserve. No doubt he would label me a spoilsport.

I have since learned there are bylaws preventing the use of model aircraft in city parks and reserves but this raises the question of the use of drones, machines with far more capability for intrusion, and danger, than model aircraft with limited flying capacity.

Are old laws keeping pace with this new technology?

By coincidence, on the day of the drone experience I read in the Mercury of a conference in Hobart, which in part was considering the same issue.

The conference of the Australian and New Zealand Association of Planning Schools was examining the latest challenges and innovation in planning and education. The impact of new technology on environment was firmly on the agenda.

Among discussion was a need for updated legislation, or even new legislation, to consider not only the safety issues surrounding drone use but to establish boundaries for their flying, namely were they intrude on both the natural and human environment.

The author of the Mercury article on the eve of the conference, Dr Pip Wallace, a lecturer on environmental planning and law at the University of Waikato, in New Zealand, noted that drone use was banned in Tasmanian parks, but the impact drones might have on wildlife outside of protected areas was also to be raised. This concerned possible collisions with endangered birds.

Wedge-tailed eagles, especially, are fiercely territorial and lay claim to the skies over feeding and nesting areas. They have long been known to attack model planes. Video footage of such attacks are common on social media but incidents involving drones are featuring more frequently, as drone purchase and use increases dramatically, outstripping modest sales of model planes.

Such incidents have the capacity to injure birds, when propeller comes into contact with skin, feather and bone.

Noise pollution is also an issue affecting birds, and not just humans seeking solitude in the bush. It is not something new, and the drones have merely served to put noise pollution back in the spotlight.

Although human-inspired sound might not directly harm birds — compared, say, with collisions with aircraft, power poles and wind farms — noise in recent years has been found in much research to have an impact on bird mating rituals.

Male birds sing to declare territory and advertise for a mate, and loud noise can hamper this process.

Birds in North American and European cities have been found to moderate their calls, making them louder and possibly shorter to counteract human noise. Sometimes they fail to make themselves heard above the din and fail to breed.

In the US, a campaigner for tranquillity, Gordon Hempton, established an area of a national park devoted to silence, in the same way some parks concentrate on a single species or habitat.

His One Square Inch of Silence foundation has persuaded some airlines to route aircraft, except in emergencies, clear of the corner of the Olympic National Park in Washington State that’s become free of Anthropocene noise.

Drones have in recent years been added to the banned list in the zone and, when the dawn chorus starts up, the bluebirds only have to compete for the airwaves among themselves.

Don Knowler goes looking for a bird but discovers, to his horror and dismay, a noisy flying robot