We assessed the vulnerability of the native Mediterranean pond turtle to encroachment by the invasive red-eared slider in southern Spain. We first obtained an ecogeographical favourability model for the Mediterranean pond turtle. We then modelled
the presence/absence of the red-eared slider in the Mediterranean pond turtle range and obtained an encroachment favourability
model.We also obtained a favourabilitymodel for the red-eared slider using the ecogeographical favourability for theMediterranean
pond turtle as a predictor. When favourability for the Mediterranean pond turtle was high, favourability for the red-eared slider
was low, suggesting that in these areas the Mediterranean pond turtle may resist encroachment by the red-eared slider. We also
calculated favourability overlap between the two species, which is their simultaneous favourability. Grids with low overlap had
higher favourability values for the Mediterranean pond turtle and, consequently, were of lesser conservation concern. A few grids
had high values for both species, being potentially suitable for coexistence.Grids with intermediate overlap had similar intermediate favourability values for both species and were therefore areas where the Mediterranean pond turtle was more vulnerable to encroachment by the red-eared slider.We mapped the favourability overlap to provide amap of vulnerability of theMediterranean pond turtle to encroachment by the red-eared slider.
