Chew card processing protocol

This protocol describes how to digitally extract a measure of rodent activity from chew cards based on the amount of area that has been chewed for each individual card. Chew cards are more commonly used as presence/absence devices, with the standard measure being the proportion of cards in a network that have been chewed. The activity index derived from the attach protocol provides more fine-scale activity metrics, as the intensity with with each card has been chewed (rather than just whether or not the card has been chewed) is used as the monitoring metric. Chew cards 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 peanut-butter mixture. Chew cards were deployed for a continuous one-month period and were the collected and processed digitally. For information about chew card deployment and use see associated research article.