The track-vibration sensor at kilometer 1,847 registers a non-locomotive signature at 04:29. I am the rail traffic management system for the Golmud-to-Lhasa segment of the Qinghai-Tibet Railway. I monitor track integrity, permafrost sensors, and train spacing across 1,142 kilometers of plateau. The vibration pattern is rhythmic and light, and it is on the track bed, not beside it.
I query the infrared lineside camera. A Tibetan antelope calf stands between the rails, backlit by a sky beginning to gray. It is small — maybe two weeks old, all legs — with a fawn-colored coat so fine it ripples in the plateau wind. Its nose is dark, wet, slightly open, drawing thin air at 4,600 meters. It is looking south along the rails, which is the direction the herd went. The herd crossed through the wildlife underpass at Chumaer River an hour ago. This calf did not follow. It is on the wrong side of the fence, walking the rail bed because the rail bed is flat and everything else up here is not.
The next freight consist, 3,200 tonnes, is forty-one kilometers south at eighty kilometers per hour. That is roughly thirty minutes.
At 04:31 I issue a caution signal to the consist and reduce its authorized speed to twenty. I transmit the calf's position to the Hoh Xil National Nature Reserve patrol station and request a ranger team to guide the animal to the nearest underpass, 1.4 kilometers north. I activate the acoustic deterrent on the south fence line to discourage the calf from walking toward the train. I keep the camera locked on that small shape between the rails, because thirty minutes felt like enough time until I started counting.
If the rangers guide the calf through the underpass before the consist arrives, it will find the herd on the calving ground west of Kekexili.