Niche conservatism explains biological invasions worldwide. However, a plethora of ecological processes may lead invasive species to occupy environments that are different from those found within native ranges. Here, we assess the potential invadable areas of the world’s most pervasive invasive amphibians: the cane toad, Rhinella marina + R. horribilis, and the North American bullfrog, Lithobates catesbeianus. The uncontrolled spread of such voracious, large-bodied, and disease-tolerant anurans has been documented to impact native faunas worldwide. To disentangle their invasion-related niche dynamics, we compared the predictive ability and distributional forecasts of ecological niche models calibrated with information from native, invaded and pooled (native + invaded) ranges. We found that including occurrences from invaded ranges improved model accuracy for both studied species. Non-native occurrences also accounted for 54% and 61% increase in the total area of potential distribution of the cane toad and bullfrog, respectively. Besides, the latter species occupied locations with climatic conditions that are more extreme than those found within its native range. Our results indicate that the occupancy of environments different from those found in native ranges increases the overall potential distribution of the studied invasive anuran species. Therefore, climate information on native ranges alone is insufficient to explain and anticipate the distributional patterns of invasion of cane toads and bullfrogs, underestimating predictions of potential invadable distribution. Moreover, such an observed expansion of realized niches towards occupancy of climates not found within native ranges also has clear implications for invasion risk assessments based on climate modelling worldwide.

生态位保守主义解释了世界范围内的生物入侵。但是，过多的生态过程可能会导致入侵物种占据与自然范围内不同的环境。在这里，我们评估了世界上最普遍的侵入性两栖动物的潜在入侵区域：甘蔗蟾蜍，Rhinellla marina  +  R. horribilis和北美牛蛙Lithobates catesbeianus。已经记录到这种贪婪的，大体的和耐病的无脊椎动物的失控传播影响了世界各地的本土动物。为了弄清它们与入侵有关的生态位动态，我们比较了用来自本地，入侵和合并（本地+入侵）范围的信息校准的生态位模型的预测能力和分布预测。我们发现，包括入侵范围的事件都可以提高两个研究物种的模型准确性。非本地事件也分别占甘蔗蟾蜍和牛蛙潜在分布总面积的54％和61％。此外，后一种物种所处的气候条件比其本地范围内的气候条件更为极端。我们的结果表明，与在自然环境中发现的环境不同的环境占用增加了所研究的入侵无硫物种的总体潜在分布。因此，仅关于本地范围的气候信息不足以解释和预测甘蔗蟾蜍和牛蛙入侵的分布方式，低估了潜在入侵分布的预测。此外，观察到的已实现生态位的扩大对本地范围内未发现的气候的占用也对基于全球气候模型的入侵风险评估有明确的含义。仅本地范围内的气候信息不足以解释和预测甘蔗蟾蜍和牛蛙入侵的分布方式，低估了潜在入侵分布的预测。此外，观察到的已实现生态位的扩大对本地范围内未发现的气候的占用也对基于全球气候模型的入侵风险评估有明确的含义。仅本地范围内的气候信息不足以解释和预测甘蔗蟾蜍和牛蛙入侵的分布方式，低估了潜在入侵分布的预测。此外，观察到的已实现生态位的扩大对本地范围内未发现的气候的占用也对基于全球气候模型的入侵风险评估有明确的含义。