Previous studies on avian deaths by wind turbines generalized from studies done at Altamont Pass CA, which have ancient, more dangerous turbines. Modern wind turbines are much larger, slower, do not have latticing, are out of hunting range of raptors, and lower than small bird migration paths. A new peer-reviewed study shows that avian death rate from these new turbines is less than 0.01% of the small passerby bird population, which is “biologically insignificant,” especially considering that 30% die of natural causes each year. A study of raptor and water bird death from wind turbines is coming.
The avian mortality rate found in the new study updates estimates from previous studies that over-sampled information from the earliest wind farms at California’s Altamont Pass. The faster-turning small kilowatt-level 1980s turbines were low on the hillside, where raptors swoop on updrafts to hunt prey on the ground.