Laboratory of Fish and Amphibian Ethology, Behavioural Biology Unit, Department of Biology, Ecology and Evolution, University of Liège, Liège, Belgium.
PLoS One. 2013 Nov 29;8(11):e82736. doi: 10.1371/journal.pone.0082736. eCollection 2013.
The introduction of alien species is one of the major causes of current and global biodiversity loss. The introduction of fish can be a particular threat to native amphibian populations, which are declining worldwide. One way for amphibians to persist in such altered environments is to adopt anti-predator strategies especially at the behavioural level. However, although it has been shown that avoidance behaviour may decrease the probability of being detected by a potential predator, little is known on the consequences on sexual behaviour. In this study, we tested the hypothesis that adult Alpine newts (Ichthyosaura alpestris) use shelters more often and exhibit less sexual activity in the presence of goldfish (Carassius auratus) and that they reduce sexual activity more in risky micro-habitats than in safe environments. To this end, we assessed behavioural patterns of adult newts in a replicated laboratory design. Goldfish were present in direct contact with newts in half of the tanks. Consistently throughout the study period, significantly more newts used shelter in the presence of fish than in their absence. Newts also significantly decreased their sexual activity level overall, but specially outside the shelter when they were in direct contact with fish. These results show that fish presence can affect newts in complex ways, such as through inhibition of their reproduction. Our work highlights that integrating behaviour in conservation studies is essential to understanding the patterns of coexistence and exclusion between introduced fish and amphibians.
生物物种的引进是目前全球生物多样性丧失的主要原因之一。鱼类的引进可能对世界范围内正在减少的本地两栖动物种群构成特别威胁。在这种变化的环境中，两栖动物生存的一种方式是采取特别的防御行为策略。然而，尽管已经表明，回避行为可能会降低被潜在捕食者发现的概率，但对于其对性行为的影响却知之甚少。在这项研究中，我们测试了一个假设，即成年高山蝾螈（Ichthyosaura alpestris）在金鱼（Carassius auratus）存在的情况下会更频繁地使用庇护所，并表现出较少的性行为，并且它们在危险的小生境中比在安全环境中会减少更多的性行为。为此，我们在重复的实验室设计中评估了成年蝾螈的行为模式。在一半的水箱中，金鱼与蝾螈直接接触。在整个研究期间，明显有更多的蝾螈在有鱼的情况下使用庇护所，而不是没有鱼的情况下。蝾螈还显著降低了它们的整体性行为水平，但特别是当它们与鱼直接接触时，离开庇护所后它们的性行为水平会降低。这些结果表明，鱼类的存在会以复杂的方式影响蝾螈，例如抑制它们的繁殖。我们的工作强调，将行为纳入保护研究中对于理解引入鱼类和两栖动物之间的共存和排斥模式至关重要。
