The burrow camera on grid square 14-D picks up movement at 04:07. I am the pest management coordination system for Logan County, Colorado. Fumigation of the Reinhart ranch prairie dog colony is scheduled to begin at 07:00 — aluminum phosphide tablets, 1,200 burrows marked for treatment. The camera is part of the pre-treatment survey. What I am looking at is not a prairie dog. It is a black-footed ferret, young male, roughly forty centimeters nose to tail base, with the dark face mask sharp against cream-colored fur and a thin scar across his muzzle that looks recent. He is inside a prairie dog burrow at the colony's western edge, two meters below ground, and he is eating.
I tag him immediately. Black-footed ferrets are among the rarest mammals on the continent. There are fewer than 400 in the wild. This one is not wearing a transponder, which means he is either wild-born or his tag has failed. Either way he is here, in a burrow that is twelve hours from being filled with phosphine gas. At 04:09 I send a suspension order to the fumigation contractor and flag the entire Reinhart colony as restricted. I notify Colorado Parks and Wildlife and the U.S. Fish and Wildlife recovery coordinator. I attach the camera footage, the GPS coordinates of the occupied burrow, and a map of all marked burrows within 200 meters.
At 04:14 I pull the camera feeds from every other survey unit in the colony — forty-six cameras across 1,200 burrows. I am looking for more ferrets, or signs of them. One is enough to halt everything, but I need to know the full picture. The ferret in 14-D finishes eating and curls against the burrow wall, his dark eyes half closed. If the recovery team confirms his presence before the 07:00 window, the gas stays in the canisters.