Biogeography of the golden-striped salamander Chioglossa lusitanica : a field survey and spatial modelling approach

Chioglossa lusitanica is a streamside salamander endemic to the northwestern corner of the Iberian Peninsula. In an extensive field survey we found the species to be widely distributed across northwestern Portugal. The distribution data were used to identify macroenvironmental parameters related to the presence of the species in Portugal, and to produce a descriptive distribution model for C. lusitanica. We modelled the species distribution based on five environmental parameters (precipitation, relief, July temperature, number of frost months and hardness of water) selected by logistic regression analysis. The model yielded a high score of correct classification (95%). Excluding parameters unavailable for Spain the model included four parameters (precipitation, relief, July temperature and altitude) and had a 93% correct classification score. Extrapolation of the model to Spain yielded a correct classification of 92% and served as a validation of the modelling technique in an independent area. The models indicate the existence of several potentially suitable areas outside the known distribution of the species, providing clues about the species historical biogeography. The models, through the identification of highly suitable and stable protection regions, may contribute to informed conservation planning.