A simple method for estimating the effective detection distance of camera traps

Hofmeester and colleagues addressed a key parameter for density methods like the Random Encounter Model and distance sampling: how far in front of a camera animals are actually detected. Because the passive infrared sensor's reach varies with species size, temperature, vegetation, and camera model, assuming a fixed detection distance introduces bias. They proposed a straightforward field and analytical method to estimate the effective detection distance directly from the data, using the distribution of distances at which animals first appear. This calibration improves the accuracy of recognition-free density estimates that depend on detection-zone geometry. The paper is a practical, widely cited contribution that helps researchers quantify a previously hand-waved quantity and produce more reliable unmarked-density estimates.