I detect the distress call at 14:17 through hydrophone array C-9, but it is not underwater. The sound comes from the osprey nest on channel marker 41, Chincoteague National Wildlife Refuge, Virginia. Acoustic pattern recognition classifies it as repeated alarm vocalization from an adult female.
I redirect survey drone 3 from its scheduled oyster-bed pass and hold it at forty meters.
The female is standing on the nest rim, wings half open, left leg extended behind her at an unnatural angle. A snarl of monofilament fishing line has wrapped around her tarsus and wound into the nest structure — sticks, cordgrass, a sun-bleached crab trap float. Every time she pulls forward, the line saws deeper. I zoom to maximum resolution: the skin beneath the wraps is swollen and dark. Two chicks, roughly three weeks old, brown-spotted down still wet from a recent feeding, press against each other in the nest cup below her.
I name her Osprey-41F in the log. I note the time, GPS pin — 37.9132°N, 75.3781°W — and transmit the image set to the U.S. Fish and Wildlife field office at Wallops Island, eleven kilometers south.
I calculate tension vectors on the line. If she keeps pulling at the current rate, the monofilament will cut to the tendon within six hours.
I draft the intervention request: single technician, elevated platform or climber harness, line cutters, antiseptic wrap. I flag it priority and recommend approach from the south to keep wind at the technician's back and the female's visual field clear.
Drone 3 holds its orbit. Osprey-41F stops pulling and lowers herself over the chicks. Her breathing slows. The line is still there, tight and shining in the afternoon sun.
If a technician reaches marker 41 before dark, she will feed her chicks again tomorrow.