Arboreal Cover Boards: Using Artificial Bark to Sample Cryptic Arboreal Lizards

Abstract: Arboreal reptiles are often difficult to capture because of their cryptic nature and propensity to flee out of reach when approached. In addition, arboreal lizards often seek refuge under loose or peeling tree bark; therefore researchers often remove it to catch them, thereby potentially damaging habitat. Using arboreal cover boards, or “artificial bark,” might reduce damage to natural shelter sites, allowing repeated surveys. We compared capture success and population structure of samples obtained by two capture methods—active searches (visual encounter surveys [VES]) and arboreal cover boards used as artificial bark—on two species of arboreal lizards, Inland Snake-eyed Skinks (Cryptoblepharus australis) and Dubious Dtellas (Gehyra dubia). Two types of arboreal cover boards (cardboard and closed-cell foam) were strapped around the main trunks of trees with elastic straps. Systematic VES during the day (for Cryptoblepharus) and at night (for Gehyra) were conducted in conjunction with monitoring of arboreal cover boards. Diurnal VES for Cryptoblepharus had low capture success (17.1% of observed animals) compared to arboreal cover boards (49.6%). Nocturnal spotlight surveys for Gehyra resulted in a high number of observations, but low capture success (44.9% of observed animals) compared to arboreal cover boards (83.5%). There was no difference in the capture success between cover board materials. Using arboreal cover boards as artificial bark increased hand captures of arboreal lizards, and preserved natural bark shelters that would have otherwise been destroyed by peeling bark during visual encounter surveys.