Our results show significant negative effects of P. waltl abundances on the anurans Alytes obstetricans, Epidalea calamita, and Pelodytes punctatus. Species adapted to shorter hydroperiods such E. calamita and P. punctatus show lower densities in the presence of P. waltl larvae. A. obstetricans, with preference for longer hydroperiod ponds, seems to better thrive in sites where the newt is absent. This is the first field work suggesting a negative impact of P. waltl on coexisting anurans, even though more studies are needed to disentangle other negative effects related to unmeasured environmental variables or biotic interactions, which can be important according to the large variation encompassed by the random variables of site and sampling period in the mixed models. Leer más.