How Do Animals Know to Avoid Power Lines?

For years, scientists couldn't explain why so many animals avoided the areas around giant towers of power lines. In 2014, after examining the results of a study of reindeer in Norway, researchers determined that reindeer -- and about 35 other species that are sensitive to ultraviolet radiation -- see power lines as glowing, flashing bursts of light that frighten them. High-voltage power lines generate the UV light because of a build-up of ionized gas, known as a corona discharge. When the gas dissipates, flashes of light are emitted. And the higher the build-up, the larger the flashes.

The flash that makes them flee:

• The problem is larger than the fact that glowing power lines are unsettling to animals. Biologists think these flashes (not visible to humans) may actually cause animal communities to fragment.
• Power companies try to reduce build-ups, which actually indicate an inefficiency in the line that signifies lost power. Inspectors wear special goggles to find problem areas, and repair them.
• According to researcher Nicolas Tyler, an ecologist at the Arctic University of Norway, “fragmentation of habitat by infrastructure is the principle global threat to biodiversity. It is absolutely major.”