How we helped TasNetworks reduce bird deaths

There are about 120 wedge-tailed eagle breeding pairs left in Tasmania, less than 110 pairs of grey goshawks and less than 200 pairs of white-bellied sea eagles. These birds are fighting an uphill battle against both habitat destruction and collisions with power lines.

Seeing an opportunity to make a difference, TasNetworks set out to conduct a long-term conservation project using over 25,000 Firefly Bird Diverters and Birdmark Afterglow diverters to deter these precious birds from becoming entangled in lines (and causing expensive power outages).

The Tasmanian wedge-tailed eagle is listed as a threatened species and has suffered a decline in breeding rates over recent years. In their 2016-17 annual report, TasNetworks drew attention to the death of 12 rare Tasmanian wedge-tailed eagles as a direct result of flying into live conductors or perching on power poles.

Playing an active role in bird conservation was a key priority for TasNetworks, so their team developed a long-term strategy to protect these large raptors that frequently become wounded or electrocuted when tangled in power lines.

As part of their commitment to environmental protection, TasNetworks developed the “Conservation of Protected Wildlife Species Five Year Threatened Birds Strategy (2016-2021)” – a plan to address impacts on wildlife health and biodiversity caused by Tasmania’s transmission and distribution network.

Identified hot spots for wedge-tailed eagle collisions were identified, including areas such as the Derwent Valley and several agricultural areas across the upper and lower Midlands, along the East Coast and inland North-West of the state.

Learning that tall structures such as power lines and poles can be difficult for an eagle to perceive in flight, TasNetworks looked for a solution that would enhance the visibility of power lines in critical areas.

A program was undertaken using a combination of strategies to deter birds from making contact with the network. In an article published by ABC News, TasNetworks said that "our design team is encouraged to specify mitigation on higher risk lines and locations: bird perches, insulator covers, conductor covers, bundled cable, and bird flight diverters."

Using this ‘toolkit’ of solutions meant that not only would bird injuries and electrocutions be reduced, but it would also have the added benefit of reducing disruption to the power supply caused by bird collisions.

TasNetworks understood that eagles and other birds of prey often caused power outages, creating unnecessary repair and labour costs associated with sending emergency crews to remote locations to fix the damage.

Any reduction in deaths would be a positive result for both biodiversity and network resilience, however, the program also had the knock-on effect of reducing the emotional distress caused to repair and maintenance crews who had to deal with rescuing injured birds or untangling dead wedge-tailed eagles – enormous birds with a wingspan of up to 2.3 metres.

Along with their other mitigation plans, installing bird diverters was prioritised as a key strategy to reduce the damage to the wedge-tailed eagle population.

TasNetworks undertook research into the best type of bird diverters available to install throughout their networks, settling on a combination of the Birdmark Afterglow 135mm diameter diverter, and the swivelling reflective Firefly ‘flappers’ – both of which are effective during the day and night.

Birdmark Afterglow

The Birdmark Afterglow is a perforated disc that functions during the day using visual movement and refracted light, and throughout the night by emitting a purple ultraviolet light, with a glow that lasts for 10-12 hours after sundown.

Installed every 3 - 5 metres on powerlines, the overall effect is distracting to birds, causing them to divert their flight path and avoid collisions. The Birdmark Afterglow also handles extreme wind conditions with 90% of wind passing through the perforations in the disc, making it ideal for Tasmania’s wild and rugged environment.

Birdmark Afterglow bird markers are suitable for conductors up to 132kV and can be easily attached from the ground using a hot stick and application tool.

Firefly Bird Diverters

The Firefly uses reflected sunlight during the daylight hours and luminescent light emissions during dusk and nighttime hours – a time when birds are most susceptible to powerline accidents.

The sparkling refraction of light caused by the diverter allows birds to change their flight pattern to avoid marked wires. The rotational speed of the Firefly also acts as a diverter and scares off birds, and after dark, the glowing light emitted creates a ‘hazing’ effect that birds find uncomfortable, causing them to avoid the area.

Using a snap-fast clamp, the diverter holds securely on conductors from 6-70mm OD and can be easily attached from the ground using a hot stick and an application tool, or also by drone, ensuring the utmost safety for installation crews.

Both of these solutions were selected ahead of competitor products, which lacked any night-time deterrent capabilities.

Since January 2016, TasNetworks has installed over 25,000 of Summit Power’s Bird Diverters. The specialist devices have been proven to reduce the number of Tasmanian wedge-tailed eagle fatalities.

Asset Area Manager Michael Philpott notes in a TasNetworks video that maintenance crews also appreciate the reduction in distressing callouts to remove dead birds.

“The guys are more passionate now, they understand they’re a threatened species, they understand the sort of beautiful bird they are, and they certainly let you know [they care] any time I get a phone call that there’s been an eagle death anywhere or a sighting of an eagle death on our power lines.”

TasNetworks has also rolled out a state-wide awareness campaign involving the general public and wildlife conservation groups such as Raptor Refuge in Kettering, south of Hobart.

This united approach is helping to ensure the program’s success by encouraging the public to identify and report injured birds, and by working with raptor experts to better understand how to protect these majestic birds for the future.

Summit Power is committed to further research using data obtained from the TasNetworks program in order to develop products that will protect other wildlife species. We are proud to play such a pivotal role in the conservation of our native wildlife and will continue to strive for excellence in our provision of powerline safety markers to energy networks around Australia.