Abstract Knowing the causes of biological invasion success can be relevant to combat future invasive processes. The recent invasion of the horseshoe whip snake Hemorrhois hippocrepis on the island of Ibiza provides the opportunity to compare natural history traits between invasive and source populations, and to unravel what makes this snake a successful invader that is threatening the only endemic vertebrate of the island, Podarcis pityusensis. This study compares the basic reproductive traits of mainland native and invasive populations of the snake. Our results revealed that invasive populations were characterized by female maturity at a smaller size, extended reproductive period, and much lower reproduction frequency compared to the native population. In contrast, some major reproductive traits—the abdominal fat body cycle, clutch size, hatchling body size, and hatchling body condition, did not differ between the two populations. Some of these results must reflect the environmental differences in the recently invaded island with respect to the source area, and overall plasticity of reproductive traits. Plasticity is evolutionarily interesting, and may aid the successful growth of this species in their invasiveness of Mediterranean islands like Ibiza. The most significant finding is that this expression of phenotypic plasticity occurred rapidly in this invasive population, within a period of 14 years maximum. Our results on the reproduction ecology of the invasive population were not conclusive regarding the factors determining the invasiveness of the snake and pointed to alternative causes.

中文翻译：

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伊维萨岛上最近入侵的蛇痔疮的繁殖生态学


摘要 了解生物入侵成功的原因可能与对抗未来的入侵过程相关。最近马蹄鞭蛇马蹄鞭蛇对伊维萨岛的入侵为比较入侵种群和源种群之间的自然历史特征提供了机会，并揭示了是什么使这种蛇成为威胁该岛唯一特有脊椎动物的成功入侵者，松鼠。这项研究比较了大陆本土蛇类和入侵蛇类的基本繁殖特征。我们的研究结果表明，与本地种群相比，入侵种群的特点是雌性成熟时体型较小、繁殖期较长、繁殖频率低得多。相比之下，两个种群之间的一些主要生殖特征——腹部脂肪周期、产窝大小、孵化体大小和孵化体状况——没有差异。其中一些结果必须反映最近被入侵的岛屿相对于源区的环境差异，以及生殖性状的整体可塑性。可塑性在进化上很有趣，并且可能有助于该物种在入侵伊维萨岛等地中海岛屿时成功生长。最重要的发现是，这种表型可塑性的表达在这个入侵种群中迅速发生，最长持续时间为 14 年。我们对入侵种群繁殖生态学的研究结果对于决定蛇入侵的因素并没有得出结论，并指出了其他原因。