Disturbance Budget Models for Conservation Cave Access

A single arousal episode in a Myotis lucifugus costs roughly 108 milligrams of fat, equivalent to 68 days of normal torpor. Across a winter, a dozen researcher entries can cost a bat its survival. This post works through how to build a disturbance budget for a conservation cave access plan, and how to track it inside EchoQuilt.

Merlin Tuttle's synthesis of disturbance research cites Thomas 1995 data showing each forced arousal costs a Myotis lucifugus about 108 milligrams of fat, equivalent to 68 days of torpor. Thomas's 1995 work on nontactile human disturbance established that hibernating bats are sensitive to human presence well before contact — voice, headlamp, and footfall trigger arousals at measurable distances. A 2024 Scientific Reports paper on researcher disturbance showed that researcher entries cause abnormal arousal patterns that persist beyond the visit itself.