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

<p><u>Aim</u> 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 <i>Phelsuma grandis</i>.</p> <p><u>Location</u> Madagascar and Florida, USA.</p> <p><u>Methods</u> To determine the climatic conditions associated with the native range of <i>P</i>. <i>grandis</i>, we used native-range presence-only records and <i>Bioclim</i> 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 <i>P</i>. <i>grandis</i> and the closely related parapatric species <i>P</i>. <i>kochi</i>.</p> <p><u>Results</u> Despite performing well within the native range, our Madagascar <i>Bioclim</i> model failed to identify suitable climatic habitat currently occupied by <i>P</i>. <i>grandis</i> 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 <i>P</i>. <i>kochi</i>. The model built using the combined <i>P</i>. <i>kochi</i>/<i>P</i>. <i>grandis</i> dataset modestly improved the prediction of the range of <i>P</i>. <i>grandis</i> in Florida, thereby implying competitive exclusion of <i>P</i>. <i>grandis</i> by <i>P</i>. <i>kochi</i> from habitat within the former's fundamental niche. These findings thus suggest ecological release of <i>P</i>. <i>grandis</i> in Florida. However, because ecological release cannot fully explain the divergent occupied niches of <i>P</i>. <i>grandis</i> in Madagascar versus Florida, our findings also demonstrate some degree of <i>in situ</i> adaptation in Florida.</p> <p><u>Main conclusions</u> Our models suggest that the discrepancy between the predicted and observed range of <i>P</i>. <i>grandis</i> in Florida is attributable to either <i>in situ</i> adaptation by <i>P</i>. <i>grandis</i> within Florida, or a combination of such <i>in situ</i> adaptation <i>and </i>competition with <i>P</i>. <i>kochi</i> in Madagascar. Our study demonstrates that climate-matching species distribution models can severely underpredict the establishment risk posed by non-native herpetofauna.</p>