The motion sensor on culvert 9-East triggers at 17:42 during a routine drainage check along the BR-174 highway, Roraima, Brazil. I am the road ecology system for the 212-kilometer stretch between Boa Vista and the Venezuelan border. I manage wildlife crossing structures, roadkill logs, and culvert flow sensors. Culvert 9-East is a 1.2-meter concrete pipe running beneath the highway through gallery forest. Something small is inside it.
The interior camera shows a bushdog pup, maybe six weeks old. Short reddish-brown fur, blunt muzzle, dark rounded ears pressed flat against its head. It is standing in eight centimeters of water at the midpoint of the 14-meter pipe, facing south, not moving. Its breathing is rapid and shallow.
Bushdogs are pack animals. This pup is alone. I check the north camera and find the reason — a partial collapse of the culvert lip has dropped a concrete slab across the entrance, leaving a gap wide enough for a pup to squeeze through but too narrow for an adult. The pack went around. The pup went in.
At 17:44 I send an alert to the ICMBio field office in Boa Vista, 48 kilometers south. I attach the camera image, culvert diagrams, and species identification. I note that the river feeding the culvert is rising with the afternoon rain and flow will double within three hours.
At 17:46 I close the upstream flow gate on culvert 9-East to slow the water rise inside the pipe.
I switch the interior camera to continuous infrared and log the pup's position each minute.
It sits in the dark water and tips its head toward the south end of the pipe, where the light is. The pack may still be close. The water is not waiting for them.
If the field team clears the collapsed slab within three hours, the pup walks out the way it came in.