Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), 38206, San Cristóbal de La Laguna, Tenerife, Canary Islands, Spain.
Sci Rep. 2022 Oct 29;12(1):18249. doi: 10.1038/s41598-022-22583-5.
When facing novel invasive predators, native prey can either go extinct or survive through exaptation or phenotypic shifts (either plastic or adaptive). Native prey can also reflect stress-mediated responses against invasive predators, affecting their body condition. Although multiple native prey are likely to present both types of responses against a single invader, community-level studies are infrequent. The invasive California kingsnake (Lampropeltis californiae) a good example to explore invasive predators' effects on morphology and body condition at a community level, as this invader is known to locally extinct the Gran Canaria giant lizard (Gallotia stehlini) and to notably reduce the numbers of the Gran Canaria skink (Chalcides sexlineatus) and the Boettger's gecko (Tarentola boettgeri). By comparing a set of morphological traits and body condition (i.e. body index and ectoparasite load) between invaded and uninvaded areas for the three squamates, we found clear evidence of a link between a lack of phenotypic change and extinction, as G. stehlini was the single native prey that did not show morphological shifts. On the other side, surviving C. sexlineatus and T. boettgeri exhibited phenotypic differences in several morphological traits that could reflect plastic responses that contribute to their capacity to cope with the snake. Body condition responses varied among species, indicating the potential existence of simultaneous consumptive and non-consumptive effects at a community level. Our study further highlights the importance addressing the impact of invasive predators from a community perspective in order to gain a deeper understanding of their effect in native ecosystems.
当面临新的入侵捕食者时，本地猎物要么灭绝，要么通过适应或表型转变（可塑性或适应性）幸存下来。本地猎物也可以对入侵捕食者产生应激介导的反应，从而影响它们的身体状况。尽管多种本地猎物可能会对单一入侵物种产生这两种反应，但社区层面的研究却很少。入侵的加利福尼亚王蛇（Lampropeltis californiae）是一个很好的例子，可以用来探索入侵捕食者对社区水平的形态和身体状况的影响，因为这种入侵物种已知会导致加那利群岛巨蜥（Gallotia stehlini）在当地灭绝，并显著减少加那利群岛石龙子（Chalcides sexlineatus）和博氏壁虎（Tarentola boettgeri）的数量。通过比较三种蜥蜴在受入侵和未受入侵地区的一系列形态特征和身体状况（即身体指数和外寄生虫负荷），我们发现缺乏表型变化与灭绝之间存在明显联系，因为 G. stehlini 是唯一一种没有表现出形态变化的本地猎物。另一方面，幸存的 C. sexlineatus 和 T. boettgeri 在几个形态特征上表现出了表型差异，这可能反映了有助于它们应对蛇类的可塑性反应。物种间的身体状况反应不同，表明在社区层面上同时存在消耗性和非消耗性效应的可能性。我们的研究进一步强调了从社区角度解决入侵捕食者影响的重要性，以便更深入地了解它们对本地生态系统的影响。
