Detecting hazel dormice Muscardinus avellanarius with nest tubes and tracking tunnels: maximising the probability of success.

Abstract

Hazel dormice Muscardinus avellanarius are elusive, arboreal small mammals that are difficult to detect in a systematic manner. The fact that they are willing to construct their nests in artificial sites has led to the use of small plastic nest tubes as the principal survey technique in England and Wales. An alternative method uses tracking tunnels with similar dimensions to nest tubes, where their characteristic footprints can be recorded on suitable media. The results of a recent study are used here to calculate the probability of detection for each survey month using nest tubes and show how this is affected by habitat. We report on further studies of footprint tracking tunnels in areas of high rainfall. We provide guidance on duration of survey depending on the numbers of footprint tunnels deployed as well as suitable approaches to deployment and checking of tunnels. We also report on the effectiveness of commercially available tracking cards which can extend the interval between checks.