Tracking tunnel processing protocol

This protocol describes how to digitally extract a measure of rodent activity from tracking tunnels based on the amount of area of the tracking card that exhibits rodent (or target) footprints). Tracking tunnels are more commonly used as presence/absence devices, with the standard measure being the proportion of tunnel cards in a network that exhibit target species footprints. The activity index derived from the attach protocol provides more fine-scale activity metrics, as the intensity with with each card has been tracked (rather than just whether or not the card has been tracked) is used as the monitoring metric. Tracking tunnels are a standard monitoring tool for numerous invasive species including rats, mice, possums and stoats. They are baited with non-toxic lure, in this case, a dollop of peanut butter. Tracking tunnels were deployed for a continuous one-month period and were the collected and processed digitally. For information about tracking tunnel deployment and use see associated research article.