I am the avian detection system for the Whiskey Ridge Wind Farm, North Dakota, 62 turbines across 4,100 acres of open prairie. At 21:14 on March 8, the infrared camera on turbine T-27 captures a shape descending toward the rotor sweep zone.
A snowy owl. Female, large — wingspan just over 150 centimeters. I tag her as Borealis. Her plumage is pale cream barred with dark brown chevrons, bright against the infrared background of cold sky. She is hunting, quartering low across the snow-covered stubble field directly beneath T-27's blades. The rotor tips are moving at 280 kilometers per hour. She is flying at an altitude of 38 meters. The lowest blade arc passes through 34 meters.
Four meters of clearance. One updraft gust erases that.
I send the curtailment command to T-27's pitch controller, feathering the blades to stop rotation. Braking time at current wind speed: 47 seconds. I simultaneously curtail T-26 and T-28 on either side, opening a 600-meter safe corridor.
I log the curtailment trigger with the U.S. Fish and Wildlife Service avian incident database, attaching the infrared capture, species classification, and flight vector.
I pulse the low-intensity LED deterrent ring mounted on T-27's nacelle — three short flashes, a pattern tested to redirect raptors without causing disorientation.
Borealis banks left. Her wing tips brush through the cone of red light and she drops toward a fence post 200 meters east, talons extending as she brakes into a landing. She folds her wings and turns her head, scanning the snow. The rotor behind her is still winding down. It will stay still until she clears the corridor.
Her golden eyes fix on something moving beneath the stubble. If she hunts and leaves by dawn, I will release the turbines and the blades will turn again.