Datafile - In situ adaptation and ecological release facilitate the occupied niche expansion of an invasive Madagascan day gecko in Florida

Aim To investigate whether the frequently advocated climate-matching species distribution modelling approach could predict the well-characterized colonization of Florida by the Madagascar giant day gecko Phelsuma grandis.

Location Madagascar and Florida, USA.

Methods To determine the climatic conditions associated with the native range of P. grandis, we used native-range presence-only records and Bioclim climatic data to build a Maxent species distribution model and projected the climatic thresholds of the native range onto Florida. We then built an analogous model using Florida presence-only data and projected it onto Madagascar. We constructed a third model using native-range presences for both P. grandis and the closely related parapatric species P. kochi.

Results Despite performing well within the native range, our Madagascar Bioclim model failed to identify suitable climatic habitat currently occupied by P. grandis in Florida. The model constructed using Florida presences also failed to reflect the distribution in Madagascar by over-predicting distribution, especially in western areas occupied by P. kochi. The model built using the combined P. kochi/P. grandis dataset modestly improved the prediction of the range of P. grandis in Florida, thereby implying competitive exclusion of P. grandis by P. kochi from habitat within the former’s fundamental niche. These findings thus suggest ecological release of P. grandis in Florida. However, because ecological release cannot fully explain the divergent occupied niches of P. grandis in Madagascar versus Florida, our findings also demonstrate some degree of in situ adaptation in Florida.

Main conclusions Our models suggest that the discrepancy between the predicted and observed range of P. grandis in Florida is attributable to either in situ adaptation by P. grandis within Florida, or a combination of such in situ adaptation and competition with P. kochi in Madagascar. Our study demonstrates that climate-matching species distribution models can severely underpredict the establishment risk posed by non-native herpetofauna.

Methods
This datafile contains i) the datafiles used in this study, ii) the R script used to generate, project, and analyze the models presented in this paper, and iii) the output files associated with the models. It should be sufficient to recreate the model outputs as presented in the manuscript.

### 研究目的
旨在探究广受推崇的气候匹配型物种分布建模（climate-matching species distribution modelling）方法，能否精准预测马达加斯加巨人日行守宫（Phelsuma grandis）在美国佛罗里达州已被充分表征的定殖事件。

### 研究区域
马达加斯加与美国佛罗里达州。

### 研究方法
为明确马达加斯加巨人日行守宫原生分布区的气候条件，本研究利用原生分布区的仅存在数据（presence-only data）与生物气候（Bioclim）数据，构建了Maxent物种分布模型，并将原生分布区的气候阈值投影至佛罗里达州。随后，本研究采用佛罗里达州的仅存在数据构建了类似模型，并将其投影至马达加斯加。此外，本研究还基于马达加斯加巨人日行守宫及其近缘邻域物种（parapatric species）P. kochi的原生分布区存在记录，构建了第三个模型。

### 研究结果
尽管该模型在原生分布区内表现良好，但基于马达加斯加生物气候数据构建的模型，未能识别出佛罗里达州内目前被马达加斯加巨人日行守宫占据的适宜气候生境。采用佛罗里达州存在数据构建的模型同样未能准确反映马达加斯加的分布情况，出现了过度预测的问题，尤其在P. kochi占据的西部区域。基于P. grandis与P. kochi联合数据集构建的模型，对佛罗里达州内P. grandis分布范围的预测效果略有提升，这表明P. kochi会通过竞争排斥（competitive exclusion）作用，将P. grandis排除在其基础生态位（fundamental niche）内的部分生境之外。上述发现提示，马达加斯加巨人日行守宫在佛罗里达州发生了生态释放（ecological release）。然而，由于生态释放无法完全解释马达加斯加与佛罗里达州两地P. grandis占据的生态位差异，本研究结果同时证明，该守宫在佛罗里达州内存在一定程度的原位适应（in situ adaptation）。

### 主要结论
本研究的模型表明，佛罗里达州内P. grandis的预测分布与实际观测分布之间的差异，可归因于该物种在佛罗里达州内的原位适应，或是原位适应与马达加斯加境内P. kochi的竞争共同作用的结果。本研究证实，气候匹配型物种分布建模方法可能会严重低估非本土两栖爬行动物区系（herpetofauna）带来的定殖风险。

### 数据文件说明
本数据集包含：① 本研究使用的各类数据文件；② 用于生成、投影并分析本文中所呈现模型的R脚本；③ 与各模型相关的输出文件。利用本数据集即可复现论文中展示的模型输出结果。