The journalist James Delingpole has long described wind turbines as “bat chomping, bird-slicing eco crucifixes”. He does not seem to have been exaggerating. Last month saw the publication of findings from a group of American academic ecologists, that “for the first time” showed “distinct patterns of population – and subpopulation level – vulnerability for a wide variety of bird species found dead at renewable energy facilities”.
The paper continued: “Of the 23 priority bird species killed at renewable energy facilities, 11 (48%) were either highly or moderately vulnerable, experiencing a greater than or equal to 20% decline in the population growth rates.” At the greatest risk are raptors such as golden eagles, kites and owls. These birds are often all-year residents around wind farms, where they require open skies to catch wind currents, perform mating rituals, defend territory and dive for prey. For their part, modern wind turbines generate enormous air fluctuations, while massive blade tips travel at over 150mph.
Published in the journal Royal Society Open Science, the paper examined numerous wind and solar facilities in California. The state was selected since it was said to be a “global diversity hotspot” and a big developer of alternative power. Few details of bird kills have been available in the past but the report notes extensive previous slaughter caused by collisions with wind turbines and photovoltaic panels. In addition birds are killed by beams of light from concentrated solar power towers.
Among the birds in the 11 most vulnerable groups were the white-tailed kite, western yellow-billed cuckoo, western grebe, tricoloured blackbird, barn owl and golden eagle. Also said to be at “disproportionately high” relative risk were local subpopulations of horned lark, Wilson’s warbler and burrowing owl. Local subpopulations of western meadowlark, Wilson’s warbler and greater roadrunner were also noted to be affected by solar facilities, while non-local subpopulations of western meadowlark and American kestrel were affected by wind farms.