Invasive species are a major threat to island biodiversity, and their eradications have substantially contributed to the conservation of island endemics. However, the consequences of eradications on the trophic ecology of native taxa are largely unexplored. Here, we used the eradication of invasive black rats Rattus rattus and European rabbits Oryctolagus cuniculus from the Berlenga Island, in the western coast of Portugal, as a whole-ecosystem experiment to investigate the effects of the eradication of invasive mammals on the trophic niche and body dimensions of the island-restricted Berlenga wall lizard Podarcis carbonelli berlengensis over a 2-year period. Our results suggest an expansion of the isotopic niche and an intensification of the sexual dimorphism of the lizard following mammal eradication. Additionally, we found considerable variability in isotopic niche across the island and detected evidence of sex-specific and season-modulated nutritional requirements of this threatened reptile. Our findings support that the eradication of 2 of the planet’s most problematic invasive vertebrates led to changes in the lizard trophic niche and sexual dimorphism in just 2 years. This suggests that the ecological pressures—for example, prey availability and habitat structure—to which lizards are exposed have substantially changed post-eradication. Our study emphasizes the scientific value of island eradications as experiments to address a wide range of ecological questions and adds to the increasing body of evidence supporting substantial conservation gains associated with these restoration interventions.

中文翻译：

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与消灭岛状蜥蜴中的入侵哺乳动物相关的营养生态位变化：使用同位素的评估

入侵物种是对岛屿生物多样性的主要威胁，它们的根除极大地促进了岛屿特有物种的保护。然而，根除对本地分类群的营养生态学的影响在很大程度上尚未得到探索。在这里，我们使用根除来自葡萄牙西海岸 Berlenga 岛的侵入性黑鼠 Rattus rattus 和欧洲兔 Oryctolagus cuniculus 作为全生态系统实验，研究根除侵入性哺乳动物对营养生态位和岛屿限制的 Berlenga 壁蜥 Podarcis carbonelli berlengensis 在 2 年期间的身体尺寸。我们的研究结果表明，在哺乳动物根除后，同位素生态位的扩大和蜥蜴的性二态性加剧。此外，我们发现全岛的同位素生态位存在相当大的差异，并发现了这种受威胁爬行动物的性别特异性和季节调节的营养需求的证据。我们的研究结果支持，地球上两种最成问题的入侵脊椎动物的根除导致蜥蜴营养生态位和性别二态性在短短 2 年内发生变化。这表明蜥蜴所面临的生态压力（例如猎物可用性和栖息地结构）在根除后发​​生了重大变化。我们的研究强调了岛屿根除作为解决广泛生态问题的实验的科学价值，并增加了越来越多的证据支持与这些恢复干预相关的实质性保护收益。