Map Hibernacula Without Disturbing Torpid Colonies

EchoQuilt grows a centimeter-accurate sound-quilt of hibernacula from passive ambient cave acoustics — no lights, no LiDAR pulses, and no fat-burning torpor arousals.

It is late January and 18,000 little brown bats are torpid in a limestone hibernaculum in Ulster County. The annual white-nose count needs roost geometry to track substrate use as Pseudogymnoascus destructans progresses through the colony, but a LiDAR sweep would raise cave temperatures by half a degree and rouse the bats — burning fat reserves they cannot replace until insect flight returns in April. EchoQuilt rides in on a single biologist's headlamp-off entry, building the quilt from dripping, faint air movement, and the flutter of the one or two individuals that always stir on entry. Ceiling ribs, flowstone tongues, and crevice roosts resolve to centimeter accuracy without a single artificial photon. The colony never registers that anyone visited.