Table 2.
Variable importance using change in Area Under the Curve (AUC) for each environmental layer using 5 species distribution modelling algorithms a(columns) by two different background approaches (shown as random/targeted) to model the distributions of Salvator merianae (Argentine black and white tegu), Salvator rufescens (red tegu), Tupinambis teguixin (gold tegus), and the 3 combined in South America. The most important predictor in each is in bold.
| GLM | MARS | BRT | RF | Maxent | Mean ΔAUC | |
|---|---|---|---|---|---|---|
| S. merianae | ||||||
| Warmest month (BIO5) | 0.009/na | 0.002/0.006 | na/na | 0.016/0.023 | 0.007/0.006 | 0.009/0.012 |
| Coldest quarter (BIO11) | 0.289/0.335 | 0.247/0.258 | 0.256/0.276 | 0.269/0.311 | 0.278/0.278 | 0.268/0.291 |
| Precipitation (BIO12) | 0.097/na | 0.092/0.153 | 0.072/0.197 | 0.047/0.098 | 0.08/0.162 | 0.078/0.153 |
| PET | na/0.044 | 0.014/0.006 | na/na | 0.02/0.042 | 0.005/0.008 | 0.013/0.025 |
| S. rufescens | ||||||
| Warmest month (BIO5) | 0.005/na | 0.024/0.005 | na/na | 0.002/0.009 | 0.02/0.004 | 0.013/0.006 |
| Coldest quarter (BIO11) | 0.121/na | 0.119/0.119 | 0.084/na | 0.08/0.084 | 0.134/0.075 | 0.101/0.093 |
| Precipitation (BIO12) | 0.197/0.3 | 0.276/0.303 | 0.122/0.191 | 0.085/0.163 | 0.127/0.142 | 0.161/0.22 |
| PET | 0.071/0.097 | 0.034/0.045 | na/0.068 | 0.035/0.054 | 0.023/0.07 | 0.041/0.067 |
| T. teguixin | ||||||
| Warmest month (BIO5) | 0.042/na | 0.017/0 | na/na | 0.107/0.014 | 0.026/0 | 0.048/0.003 |
| Coldest quarter (BIO11) | 0.232/0.188 | 0.212/0.283 | 0.168/0.203 | 0.266/0.208 | 0.172/0.241 | 0.210/0.225 |
| Precipitation (BIO12) | 0.010/0.049 | 0.02/0.028 | 0.053/0.043 | 0.139/0.049 | 0.057/0.044 | 0.056/0.043 |
| PET | na/na | 0.006/0.001 | na/na | 0.124/0.004 | 0.05/0.004 | 0.06/0.003 |
| Combined tegus | ||||||
| Warmest month (BIO5) | 0.064/0.058 | 0.016/0.013 | na/na | 0.048/0.06 | 0.022/0.025 | 0.038/0.039 |
| Coldest quarter (BIO11) | 0.146/0.252 | 0.143/0.228 | 0.154/0.213 | 0.133/0.244 | 0.125/0.231 | 0.14/0.234 |
| Precipitation (BIO12) | 0.048/0.015 | 0.012/0.048 | 0.035/0.033 | 0.047/0.05 | 0.016/0.041 | 0.032/0.038 |
| PET | 0.014/na | 0.014/0.048 | 0.035/na | 0.052/0.03 | 0.021/0.02 | 0.027/0.032 |
aAbbreviations: SDM, species distribution model; AUC, area under the curve; ΔAUC, change in AUC; GLM, generalized linear model (logistic regression); MARS, multivariate adaptive regression splines; BRT, boosted regression trees; RF, random forest; PET, potential evapotranspiration; na, not applicable.