Barking up the right tree: comparative use of arboreal and terrestrial artificial refuges to survey reptiles in temperate eucalypt woodlands

Abstract

Context. Artificial refuges (cover boards) are a popular method to survey and monitor herpetofauna worldwide. However, one limitation of using artificial refuges in terrestrial environments is the low detection rates of arboreal species. Furthermore, destructive search techniques can damage critical microhabitat such as exfoliating rock or flaking bark of mature trees. Aim. We tested a non-destructive, passive method of sampling arboreal reptiles in fragmented agricultural landscapes in south-eastern Australia. Methods. We installed 84 artificial bark refuges consisting of strips of non-toxic, closed-cell foam attached to eucalypt trees in thirteen patches of remnant vegetation. We used Bayesian statistics to compare differences in detection rates between artificial bark refuges, terrestrial artificial refuges and active searches of natural habitat over a four year period. Key results. Active searches combined with terrestrial artificial refuges detected the most number of reptile species, including several cryptic fossorial species. Artificial bark refuges detected on average 132 times more individuals of the arboreal southern marbled gecko Christinus marmoratus than terrestrial refuges. Gecko abundance patterns were related to tree characteristics such as tree size, bark thickness and stand basal area, as well as survey year. Conclusions. Traditional survey methods such as terrestrial cover boards in combination with active searches of natural habitat may significantly underestimate counts for arboreal gecko species. Implications. Artificial bark refuges provide a cost-effective, non-destructive and durable method for surveying and monitoring arboreal reptiles in woodland environments over short to medium time frames. Foil-backed, closed-cell foam has broad application for use in spatial capture-recapture studies and long-term monitoring of arboreal reptiles. This method also may be effective for procuring records of threatened arboreal geckos or as a solution for providing temporary habitat in ecological restoration projects. Show more