Although arranged as a subspecies of terrestris by Ellerman and Morrison-Scott (1951), A. sapidus is strongly differentiated in morphological, morphometric, and chromosomal traits (Panteleyev, 1996; Reichstein, 1982a; Ventura and Sans-Fuentes, 1997). Phylogenetic analyses of cytochrome>b segregated A. sapidus from European samples of A. amphibius at a high level of percent sequence divergence (Taberlet et al., 1998, as terrestris).

Reviewed by Hinton (1926a), Corbet et al. (1970), Corbet (1978c), Reichstein (1982a), and Mitchell-Jones et al. (1999). New information covering morphology, discrimination from A. amphibius, and ecology supplied by Garde et al. (1993), Garde and Escala (1994, 1996, 1999), Ventura (2000), Ventura and Gosalbez (1990, 1992a), and Ventura et al. (1989, 1994). Population in NE Spain documented by owl pellet remains (Torre et al., 1996); distribution in N Spain and considerable range overlap with A. amphibius covered by Castien and Gosalbez (1992).