READER?S EDITORIAL: HIDING THE SLAUGHTER | East County Magazine
At the time this was very important because the industry was moving away from the smaller turbines and installing much larger turbines. Some were up to 362Kw and had blades twice as long as the 65-100Kw turbines. It was noted that these were turbines with slower rotations per minute that had the "greater windows of time" that would fool birds with the illusion of having open flight areas between the rotating blades. This was an illusion that not only fooled the birds, but to this day continues to fool people. The newest turbines at 20 rotations appear to be slow, but their blades tips can be moving much faster than with the smaller turbines at over 200 mph.
The study found that use of monopole or tubular towers associated with more avian fatalities than did lattice or vertical-axis towers. Tubular towers did not reduce mortality over lattice towers, but rather appeared to increase mortality. It was said that it was likely due to the association of tubular towers with longer blades, slower rotations and the illusion of safety created by the "greater windows of time" between blades presented to birds. It appeared that within the ranges of turbine and tower attributes, the taller towers with the slower-moving blades, and the longer time spans with which birds have to fly through the rotor plane, increased the vulnerability of birds in the APWRA.
Mortality at the APWRA for the Four Focal Raptor Species during the study period shows nearly 2 1/2 times as many carcasses in the raw data. The number of carcasses found in searches for other species went up even more. Barn owls carcasses found went from 50 in the 1998-2003 study up to 160 for 2005 -2010 period. Prairie falcons went from 2 to 6, rock doves from 196 up to 1125; horned larks from 23 up to 59, and meadowlark carcasses collected went from 96 up to 524 bodies in the last study. Even 2 Peregrine falcon carcasses were found.
With disproportionately high increases in carcasses totals across the entire mortality list, how is it possible that the latest study could conclude that mortality at the APWRA had improved?
Exclusionary Methods and Math- Without the use of the industry's new formula and exclusionary factors built in for estimating avian mortality rates, the latest Altamont mortality figures would look completely different. One of more noticeable factors from the study was the exclusion carcasses. The report states that 347 WRRS carcasses from the 2005-2010 data along with an additional 21 golden eagle carcasses excluded from mortality estimates. This is very important because I happen to know that a large number of the carcasses picked up under the WRRS program are primarily raptors. Many carcasses from the Four Focal Raptor Species were eliminated from mortality estimates. As far as I could determine no WRRS carcasses were excluded from the 1998-2003 study. But even though wind farm personnel routinely look for carcasses under wind turbines, WRRS records and bodies found outside designated search areas are considered "incidental" are not part mortality analysis.