While the human species remains divided on the costs and benefits of LED light outdoors, it appears LED luminaires are popular among other mammals and reptiles.
Sea turtle hatchlings on the waterfront of Townsville, Queensland, whose mission is to make it safely to the ocean without being snapped up by predators or losing direction, now have it easier with new LED lights that don’t emit distracting light pollution.
The turtles can get disoriented by conventional light sources, mistaking the light for the moon and crawling off in the wrong direction. ‘Over a few hours they are going to walk around in circles, use a lot of energy that they need for getting out into the deeper ocean, and it also exposes them to more predators on the beach,’ Reef HQ aquarist Krystal Huff told ABC North Queensland earlier this year.
Because LEDs are more directional than traditional light sources, Townsville City Council expects its new luminaires to be less of a disturbance to the sea turtles. It also has other benefits: the new lights will reduce the council’s power bill enough to power 20 homes and save $32,000 each year, the Townsville Bulletin has reported.
Last week Lux Review learned of an LED-lit recreational trail in Wuppertal, Germany, that simultaneously fulfils the lighting requirements of humans and endangered bats. LED luminaires have been mounted four metres high in tunnels on the path, which leaves plenty of pitch dark space above to satisfy the needs of light-shy, winged tunnel dwellers.
Insects have been reported to take a fancy to the blue light in LEDs; research by New Zealand-based institute Scion found that insect traps near LED luminaires captured 48 per cent more insects than traps near sodium-vapour light. This attraction could be fatal if it causes more insects to fall prey to predators thereby disrupting the ecosystem, Scion told Smithsonian.
But whether it is the LED technology or some other, undiscovered factor that is to blame, is still up for debate. A research paper from the University of Agriculture in Faisalabad, Pakistan, has shown that different insects are attracted to different colours of light, but won’t necessarily shun light outside their preferred spectrum if that’s what’s available. In the words of Lux Review publisher Gordon Routledge, in a recent magazine column: ‘It appears that insects, like humans, have quite complex and diverse tastes in lighting, and may well spend hours debating the colour rendering of a dung heap under different light sources.’