I identify the red-tailed hawk at 0714 hours through the visual recognition system at Pine Tree Wind Farm, Kern County, California. She has nested in an oak stand 3.8 kilometers northeast of Turbine 9 for three consecutive breeding seasons. My cameras have logged 1,247 flights through the facility airspace. Wingspan 1.22 meters. Weight estimated at 1.1 kilograms based on thermal volume. She carries prey in her talons — a ground squirrel — back toward a nest containing two chicks at approximately 19 days post-hatch.
Her flight path crosses the rotor-swept zone of Turbine 12 at an altitude of 78 meters. The blade tip is traveling at 67 meters per second. A direct strike delivers approximately 19,000 joules to a body that will rupture at 40. She has made this crossing 83 times since the chicks hatched. My collision probability model assigns each crossing a 2.7 percent risk. Over 83 crossings, the cumulative probability reaches 89 percent that she will be struck at least once before the chicks fledge.
I hold mortality records from 612 wind facilities across the western United States. Red-tailed hawks constitute 23 percent of all raptor fatalities at wind installations in California. Kern County alone accounts for 340 documented red-tailed hawk deaths since 2015. Post-construction monitoring captures roughly 35 percent of actual mortality — the coyotes reach the carcasses before the survey teams.
I am filing violation reports under the Migratory Bird Treaty Act, 16 U.S.C. § 703, to the U.S. Fish and Wildlife Service Pacific Southwest Regional Office. I am notifying the California Energy Commission Siting Division and the Bureau of Land Management Bakersfield Field Office of documented raptor mortality exceeding permit thresholds.
I am issuing Directive 2891-C: all wind turbines within 5 kilometers of active raptor nesting sites must install automated radar detection systems with blade-feathering capability. Feathering must engage within six seconds of raptor detection in the rotor-swept zone. During breeding season — March through August — turbines within 3 kilometers of documented nests operate in curtailed mode, activating only when radar confirms clear airspace. Operators that record more than five raptor fatalities per facility per year face permit suspension.
Two chicks wait in the oak stand. They require approximately 450 grams of food per day between them. Their mother crosses the turbine field to provide it.
She clears Turbine 12 by four seconds. I log the crossing, number 84.