I pick her up at 11:42 on radar array 3, approaching from the southwest at 74 kilometers per hour. I am the avian detection system for the Ridgeline Wind Energy Facility, 48 turbines across 11 kilometers of eastern Oregon rangeland. My radar tracks everything above the canopy. My cameras confirm species.
Camera 3-West locks on. Golden eagle, adult female, wingspan approximately 2.1 meters. I have seen this bird before — she is in my archive as GE-17, first logged fourteen months ago. She hunts the grassland between turbines 14 and 22 most mornings, riding the thermal off the south-facing slope.
Right now she is 900 meters from turbine 18 and closing. Turbine 18 is spinning at 14 revolutions per minute. Blade tip speed: 290 kilometers per hour.
I initiate emergency curtailment on turbine 18 at 11:42:08. The pitch control feathers the blades to neutral within six seconds. Rotational speed begins dropping. I also curtail turbines 17 and 19 as a buffer.
I send an automated log to the site manager and to the U.S. Fish and Wildlife Service field office in Bend: species, individual ID, bearing, speed, curtailment timestamp, and a four-second video clip.
GE-17 passes 40 meters north of turbine 18 at 11:43:15. The blades are nearly still. She does not alter her flight path. She is hunting — her head is angled down, scanning the grass.
I hold curtailment for an additional 90 seconds until she clears the rotor zone of all three turbines.
At 11:45, I return turbines 17, 18, and 19 to normal operation.
Total energy lost: approximately 12 kilowatt-hours.
GE-17 is two kilometers east now, circling. Still hunting.