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When a seabird zipping through Hawai‘i’s night sky hits a power line, you can hear it.
“They make this Star Wars-esque laser sound, like tawong-wow-ow-ow,” says ornithologist André Raine, mimicking the noise playfully before turning more serious. “When you know what it is, it’s unpleasant.”
The birds aren’t being electrocuted—they’re too small to close the circuit between neighboring lines—but they are being hurt, and potentially killed, by the collision, which makes a distinct sound. Raine and his colleagues at the Kaua‘i Endangered Seabird Recovery Project have recording devices dotted about the island to capture the sound.
Measuring the sound gives the scientists an idea of the scale of the problem—and how to fix it. This is particularly important for Newell’s shearwaters and Hawai‘ian petrels, endangered seabirds found only in Hawai‘i. In the recent past, the birds were so abundant their flocks darkened the sky. But between 1993 and 2013, the Hawai‘ian petrel population dropped by 78 percent and Newell’s shearwaters declined by 94 percent, says Raine. “The birds are doing really badly, and power line collisions and light attraction are certainly some of the key threats.”
When young Newell’s shearwaters head out to sea for the first time, they are guided by the Moon and starlight reflecting off the ocean. But these days, bright urban lights can disorient the young birds. Like moths, they end up circling artificial lights, and fall to the ground exhausted. If they don’t die of thirst, they’ll often fall prey to one of Hawai‘i’s many introduced predators, such as cats, dogs, and inattentive drivers.
Yet unlike complex issues such as habitat destruction, climate change, and invasive species, artificial lighting and power lines are relatively easy problems to fix.
Hitting a power line is not certain death: only nine percent of birds die after slamming into a wire. But it does add up. So Raine and his team have been collaborating with the island’s electric company, the Kaua‘i Island Utility Cooperative, to study the problem, find the worst affected areas, and test potential solutions.
One high-priority spot is Kāhili Mountain, where old power lines run through a seabird colony. In 2015, the utility moved portions of the offending lines underground and collisions dropped to zero. While that’s an obvious solution, it’s not cheap. Burying power lines costs between US $600,000 and $6-million a kilometer. Other less expensive options include moving or reorienting the lines, or removing the highest wires.
Raine’s team has also been exploring more inventive fixes. They’ve tested attaching blinking LED lights or reflectors to the wires to help birds see them. They’re also working on building a “laser fence” that can make the wires glow. This promising technique involves projecting dim green lasers along a wire’s length, which makes it stand out. A test of the laser fence suggests it is highly effective, though less so in poor weather. The team is still working on the design, which they tested to ensure it wouldn’t accidentally attract birds. The narrow lasers are “only really obvious as the bird approaches,” says Raine. “Compare that with the lights we know are a problem—upward facing, unshielded, very bright white or yellow lights.”
Every design tweaked and wire moved below ground brings Raine’s team closer to the ultimate goal: reversing the decline of these endangered birds.
“It’s a mammoth task. I think everyone appreciates that it will be very challenging, but it has to be resolved,” says Brett Hartl, who worked for the recovery project in its early days, but is now with the Center for Biological Diversity in Washington, DC.
“It’s a huge problem, but it’s a fixable problem,” says Raine. Resolving the power line issue is just one in a slew of efforts to bring back these birds, including reducing light pollution, removing introduced predators, and establishing a new colony in an area free of predators. As a result, Raine remains optimistic about the prospects for these imperiled seabirds. “They’ll be darkening the skies again,” he says.