JUNE 24, 2020
by Steve Lundeberg, Oregon State University
Suspended, rotating devices known as "flappers" may be the key to fewer birds flying into power lines, a study by Oregon State University suggests.
The findings by researchers in OSU's College of Agricultural Sciences are important because around the globe both the number of power lines and concern over bird fatalities are on the rise.
Research has documented more than 300 species of birds dying from hitting power lines, with one study estimating that more than 170 million perish annually in the United States and another estimating the global death toll to be 1 billion per year. There's also the problem of power outages that bird strikes can cause.
Conservation managers and utilities many years ago developed flight diverters, basically regularly spaced devices that make the lines more visible, as a step toward reducing the number of birds flying into the lines.
The most common type are the PVC spirals, which are durable and easy to install, but how well they actually work isn't well understood. Though they've been in use for nearly four decades, strike rates remain high for a number of species.
OSU researchers Virginia Morandini and Ryan Baumbusch were part of an international collaboration that compared the effectiveness of three types of flight diverters: yellow PVC spiral; orange PVC spiral; and a flapper model with three orange and red polypropylene blades with reflective stickers.
The flapper hangs from a power line and its blades, 21 centimeters by 6.2 centimeters, rotate around a vertical axis.