Surface characteristics limit the vertical mobility of an invasive reptile: Raw data

Preventing the spread of small, cryptic invasive reptiles poses an ongoing challenge for conservation and biosecurity worldwide. Physical exclusion barriers offer a potentially low-cost, non-toxic tool for limiting dispersal, but their effectiveness depends on, among other factors, a detailed understanding of how surface properties influence animal movement. We tested four commonly available fencing materials—polypropylene fabric, woven polypropylene, polythene sheet, and acrylic sheet—as potential barriers to climbing by a small Australian skink, <i>Lampropholis delicata </i>(Scincidae). Experiments with 18 adult skinks were conducted in enclosures under both wet and dry conditions. We quantified surface roughness using four metrics: arithmetic average roughness (Ra), total height of profile (Rt), mean spacing of profile irregularities (Rsm) and Skewness (Rsk). Climbing frequency was highest on the roughest material, polypropylene fabric (Ra=22.5, Rt=170, Rsm=466.5µm), with up to 60% of individuals ascending. In contrast, the smoother surfaces, polythene and acrylic, limited climbing to just 5% of trials, with climbs occurring only under wet conditions. This suggests that surface water may enhance adhesion and reduce the effectiveness of smooth barriers. Our findings indicate that simple vertical drift fences are unlikely to effectively manage the spread of <i>L. delicata</i>, particularly in wet environments and underscore the importance of incorporating surface roughness thresholds and moisture conditions into barrier design. Polythene sheet, with a Ra below 29, shows promise for indoor containment but would require modifications such as anti-climb lips for outdoor use.

防控小型隐秘入侵爬行动物的扩散，是全球范围内生物多样性保护与生物安全领域长期面临的难题。物理阻隔屏障是一种潜在的低成本、无毒性的扩散限制工具，但其防控效果受诸多因素影响，其中对表面特性如何影响动物运动的深入认知至关重要。我们选取四种市面常见的围栏材料——聚丙烯织物、编织聚丙烯、聚乙烯薄板与亚克力板，作为澳大利亚小型石龙子——纤细石龙子（<i>Lampropholis delicata</i>，石龙子科 Scincidae）——的攀爬阻隔屏障开展测试。我们在干湿两种环境条件下的围栏装置中，对18只成年纤细石龙子开展了攀爬实验。我们通过四项指标量化表面粗糙度：算术平均粗糙度（Ra）、轮廓最大高度（Rt）、轮廓微观不平度平均间距（Rsm）以及轮廓偏斜度（Rsk）。粗糙度最高的聚丙烯织物（Ra=22.5、Rt=170、Rsm=466.5μm）的攀爬频率最高，个体攀爬成功率可达60%。与之相对，聚乙烯薄板与亚克力板这类光滑表面的攀爬成功率仅为5%，且仅在湿润环境下才会发生攀爬行为。这表明表面附着的水分可能增强石龙子的附着能力，进而降低光滑阻隔屏障的防控效果。我们的研究结果显示，简易垂直阻隔围栏难以有效防控纤细石龙子的扩散，尤其在湿润环境中，这一发现也凸显了在屏障设计中纳入表面粗糙度阈值与环境湿度条件的重要性。Ra值低于29的聚乙烯薄板可用于室内的石龙子阻隔防控，但户外使用时需加装防攀爬凸缘等改良结构。