Non-Native species as conservation priorities: response to Díez-León et al.

I argue (Clavero 2014) that the conservation efforts devoted in Spain to non-native species (white-clawed crayfish [Austropotamobius italicus] and European mink [Mustela vison]) are an example of shifting baseline syndrome because degraded (i.e., invaded) ecosystems states are now perceived as desirable. The syndrome is further manifested in the generalized rejection of ecologically similar North American species introduced more recently (red swamp [Procambarus clarkii] and signal [Pacifastacus leniusculus] crayfish and American mink [Neovison vison]). Díez-León et al. (2014) believe this reasoning is misleading for two main reasons: lack of evidence of the non-native status of the white-clawed crayfish and European mink and lack of relevance of a species’ status as native or nonnative in setting conservation priorities. I considered whether human-mediated introduction constitutes a satisfactory explanation of the presence of the two species in the Iberian Peninsula and whether it makes sense making non-native species conservation priorities.