Trochet Audrey, Le Chevalier Hugo, Calvez Olivier, Ribéron Alexandre, Bertrand Romain, Blanchet Simon
Laboratoire Evolution et Diversité Biologique, Université Paul Sabatier (Toulouse III), Toulouse, France.
Station d'Ecologie Théorioque et Expérimentale, CNRS, Moulis, France.
PeerJ. 2019 Jan 9;6:e6053. doi: 10.7717/peerj.6053. eCollection 2019.
Inter-patch movements may lead to genetic mixing, decreasing both inbreeding and population extinction risks, and is hence a crucial aspect of amphibian meta-population dynamics. Traveling through heterogeneous landscapes might be particularly risky for amphibians. Understanding how these species perceive their environment and how they move in heterogeneous habitats is an essential step in explaining metapopulation dynamics and can be important for predicting species' responses to climate change and for conservation policy and management.
Using an experimental approach, the present study focused on the movement behavior (crossing speed and number of stops) on different substrates mimicking landscape components (human-made and natural substrates) in two amphibian species contrasting in locomotion mode: the common toad (), a hopping and burrowing anuran and the marbled newt (), a walking salamander. We tested the hypothesis that species reaction to substrate is dependent on specific ecological requirements or locomotion modes because of morphological and behavioral differences.
In both species, substrate type influenced individual crossing speed, with individuals moving faster on soil than on concrete substrate. We also demonstrated that long-legged individuals moved faster than individuals with short legs. In both species, the number of stops was higher in females than in males. In common toads, the number of stops did not vary between substrates tested, whereas in marbled newts the number of stops was higher on concrete than on soil substrate.
We highlighted that concrete substrate (mimicking roads) negatively affect the crossing speed of both studied species, with an effect potentially higher in marbled newts. Our findings corroborate negative effects of such heterogeneous landscapes on movement behavior of two amphibian species, which may have implications for the dynamics of metapopulations.
斑块间的移动可能导致基因混合，降低近亲繁殖和种群灭绝风险，因此是两栖动物集合种群动态的一个关键方面。对于两栖动物来说，穿越异质景观可能特别危险。了解这些物种如何感知环境以及它们如何在异质栖息地中移动，是解释集合种群动态的重要一步，对于预测物种对气候变化的反应以及保护政策和管理也可能很重要。
本研究采用实验方法，聚焦于两种运动模式不同的两栖动物在模拟景观成分（人造和天然基质）的不同基质上的移动行为（穿越速度和停顿次数）：普通蟾蜍（一种跳跃和挖掘的无尾目动物）和虎纹钝口螈（一种行走的蝾螈）。我们检验了这样一个假设，即由于形态和行为差异，物种对基质的反应取决于特定的生态需求或运动模式。
在这两个物种中，基质类型影响个体穿越速度，个体在土壤上的移动速度比在混凝土基质上更快。我们还证明长腿个体比短腿个体移动得更快。在这两个物种中，雌性的停顿次数都比雄性多。在普通蟾蜍中，不同测试基质间的停顿次数没有差异，而在虎纹钝口螈中，混凝土基质上的停顿次数比土壤基质上更多。
我们强调混凝土基质（模拟道路）对两个研究物种的穿越速度都有负面影响，对虎纹钝口螈的影响可能更大。我们的研究结果证实了这种异质景观对两种两栖动物移动行为的负面影响，这可能对集合种群动态产生影响。
