Abstract
The impact of wind turbines on natural environments is a current and developing issue. Effects (some small, some large) on birds have been reported world wide, yet no detailed reports have been published in Japan. I studied the effects of wind turbines on breeding birds at Aoyamakogen, Mie Prefecture, Japan, where Japan's largest wind farms is located. In this highland area 51 wind turbines have been installed. Using the territory mapping method on fine mornings during late-May and June 2007, I compared densities of territories and numbers of species of breeding birds between research plots within 200 m of wind turbines and control plots more than 850 m away from wind turbines. Both research and control plots were at the same altitude and supported the same vegetation. In research plots within broad-leaved forest, the density of territories was considerably lower (1.3 ± 0.69 territories/ha) than in control plots (5.4 ± 0.95 /ha). The density of species in research plots was also much lower (1.2 ± 0.45 /ha) than in control plots (3.1 ± 0.73 /ha). In research plots within Japanese Cypress Chamaecyparis obtusa forest, the densities of species and territories were also lower 75% than in control plots. When the number of species present before and after the construction of wind turbines was compared, species diversity was found to have fallen by 57% (from 21 species to nine species), in the Nunobikinomori reserve, indicating that wind turbines seriously disturb breeding birds.
