Invisible UV Light keeps Animals Away from High Voltage Power Cables

Irregular flashes of ultraviolet light from high voltage power lines help animals stay away from the structures.

For over decades, scientists have been puzzled at the phenomena of how mammals and birds successfully avoid high voltage power lines.  This collaborative study revealed that power lines emit irregular ultraviolet flashes at the insulators that are invisible to humans but can be spotted by birds and mammals.

The study was conducted by researchers from the University College London (UCL), Moorfields Eye Hospital, London, UIT The Arctic University of Norway and the University of Oslo in Norway

In certain Scandinavian countries, this avoidance is controversial considering the demand that power lines be placed at a distance from the wild and the semi domesticated reindeer population herded by the indigenous Saami people.

Professor Glen Jeffery at UCL Institute of Ophthalmology said, "Animals avoid man-made structures and, in the case of high voltage power lines, this can be by several kilometers.  This is perplexing because the suspended cables are neither a physical barrier nor are associated with human activity. New information about animal vision along with the characteristics of power lines provides strong evidence that the avoidance may be linked with animals' ability to detect ultraviolet flashing on power lines that humans cannot see and which they find frightening."

These power lines disrupt migration patterns of animals like reindeers. As a result, they suffer a loss of grazing land. This has a direct impact on the growth, viability and genetic variability of the animal population. In reindeers, it influences the group of human population that depend on animals for their livelihood and food.

This effect is more prominent in areas covered with snow where UV light is reflected and scattered by snow. The team claims that in the dark Arctic winter the power lines appear as lines of flashing lights to reindeers.

The finding was documented in the Conservation Biology.