Data from: Intra-specific variability of hindlimb length in the palmate newt: an indicator of population isolation induced by habitat fragmentation?

Habitat fragmentation is one of the main drivers of global amphibian decline. Anthropogenic landscape elements can act as barriers, hindering the dispersal that is essential for maintaining gene flow between populations. Dispersal ability can be influenced by locomotor performance, which in turn can depend on morphological traits, such as hindlimb length (HLL) in amphibians. Here, we tested relationships between HLL and environmental variables – road types, forests and agricultural lands – among 35 sub-populations of palmate newts (Lissotriton helveticus) in southwestern France. We expected roads to select for short-legged newts due to a higher mortality of more mobile individuals (long-legged newts) when crossing roads. Accordingly, short-legged newts were found in the vicinity of roads, whereas long-legged newts were found closer to forests and in ponds close geographically to another water body. HLL in newts was hence influenced by habitat types in a heterogeneous landscape, and could therefore be used as an indicator of population isolation in a meta-population system.生境破碎化是全球两栖动物种群衰退的主要驱动因素之一。人为景观要素可作为屏障，阻碍维持种群间基因交流所必需的扩散行为。扩散能力受运动性能影响，而运动性能又取决于形态特征，例如两栖动物的后肢长度（hindlimb length, HLL）。本研究针对法国西南部35个掌突螈（Lissotriton helveticus）亚种群，分析了HLL与道路类型、森林、农田等环境变量之间的关联。我们推测，由于穿越道路时移动性更强的长后肢个体死亡率更高，道路会对短后肢个体产生定向选择。研究结果与此预期一致：短后肢掌突螈多分布于道路周边，而长后肢个体则更贴近森林，以及地理上邻近其他水体的池塘。综上，蝾螈的后肢长度受异质景观中的生境类型调控，因此可作为集合种群系统中种群隔离程度的指示指标。