Invasive species are one of the main threats to biodiversity worldwide and the processes enabling their establishment and persistence remain poorly understood. In generalist consumers, plasticity in diet and trophic niche may play a crucial role in invasion success. There is growing evidence that invasive ants, in particular, occupy lower trophic levels in their introduced range compared to the native one, but evidences remain fragmented. We conducted stable isotope analysis at five locations distributed on two continents to infer the trophic position of the invasive ant Formica paralugubris in the native and introduced part of the range. This species forms large colonies and can be a voracious predator while feeding on sugar‐based resources as well. Whereas native populations had trophic positions comparable to that of an omnivore, the introduced populations varied from being honeydew specialists to top predators, or omnivore. Where other ant species co‐occurred, there was no overlap in their trophic niches, and F. paralugubris occupied the lower position, suggesting that trophic displacement may enable the coexistence of different ant species. Taken together, our results suggest that shifts in diet associated with changes in the trophic niche of introduced species might mediate invasion success and enable long‐term coexistence with native species.

中文翻译：

---

入侵性蚂蚁营养小生境中的可塑性说明了建立成功和长期共存

外来入侵物种是全世界生物多样性的主要威胁之一，其建立和持久性的过程仍知之甚少。在多面手消费者中，饮食中的可塑性和营养小生境可能在入侵成功中起关键作用。越来越多的证据表明，与原生蚂蚁相比，侵入性蚂蚁在其引入范围内的营养水平更低，但证据仍然零散。我们在分布于两大洲的五个位置进行了稳定的同位素分析，以推断入侵性蚁胶Form的营养位置在本机和引入的范围内。该物种形成大的殖民地，在以糖类资源为食的同时也可能是贪食的食肉动物。尽管原住民的营养位置可与杂食动物媲美，但引进的种群从蜜露专家到顶级掠食者或杂食动物不等。在其他蚂蚁物种同时发生的地方，它们的营养位没有重叠，而拟南芥（F. paralugubris）处于较低的位置，这表明营养位移可能使不同的蚂蚁物种共存。综上所述，我们的研究结果表明，与引入物种的营养生态位变化相关的饮食变化可能会介导入侵成功，并使之与本地物种长期共存。