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 th...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。人为景观要素可充当屏障，阻碍对维持种群间基因流动至关重要的扩散行为。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个掌状真螈（Lissotriton helveticus）亚种群，探究了后肢长度与环境变量——道路类型、森林及农田——之间的关联。我们推测，由于移动性更强的个体（长肢螈）穿越道路时死亡率更高，道路会对短肢螈产生选择压力。研究结果也印证了这一推测：短肢螈多分布于道路附近，而长肢螈则更靠近森林，以及地理上邻近其他水体的池塘。因此，异质景观中的生境类型会影响螈类的后肢长度，且其……