Subgenus Mus. Originally described as a subspecies of M. hortulanus (Petrov and Ruzic, 1983), but now recognized as a separate species (Boursot et al., 1993; Bonhomme, 1986; Macholán, 1996a, 1996c; J. T. Marshall, Jr., 1998; Sage, et al., 1993; and references cited therein). Mus macedonicus was first recognized as a distinct species by Kratochvil (1986), who monographed it as M. abbotti, the name still used by some researchers (Cheylan, 1991; Mezhzherin and Kotenkova, 1992; Orlov et al., 1992b, Gromov and Erbajeva, 1995, e. g.), but the holotype of abbotti is an example of M. musculus domesticus (Boursot et al., 1993; J. T. Marshall, Jr., 1998). The taxon tataricus, another synonym of M. musculus domesticus, has also been used by Russian researchers for M. macedonicus (Mezhzherin and Kotenkova, 1992; Kotenkova and Bulatova, 1994; also see discussion in Mitchell-Jones et al., 1999:284). Orlov et al. (1992b) described makovensis as a subspecies of M. abbotti.

Mus macedonicus occurs sympatrically, but never syntopically, with M. musculus domesticus (Auffray et al., 1990b; Macholán, 1996a; Petrov and Ruzic, 1985:234), and is sympatric with M. spicilegus in a narrow zone along the Black Sea (Boursot et al., 1993 and references therein). Results of allozymic and morphometric analyses of M. macedonicus (some reported as spretoides) in context of phylogenetic studies provided by Bonhomme et al. (1984), Auffray et al. (1990b), Gerasimov et al. (1990), and She et al. (1990). Forms a clade with M. musculus, M. spicilegus, and M. spretus based on analyses of DNA sequences from several different genes (Auffrey et al., 2003; Graur, 1994; Larizza et al., 2002; Lundrigan et al., 2002; Prager et al., 1996, 1998). Autosomal chromosome complement of M. macedonicus is the same as M. musculus and related species (2n = NF = 40), but has distinctive cytogenetic markers (Ivanitskaya et al., 1996b). Morphometric and immunological comparisons between Macedonian M. macedonicus and samples of M. musculus from Greek Isls in the Aegean and Ionian seas reported by Chondropoulos et al. (1995). A deeply divergent mitochondrial clade has been recongized recently by Orth et al. (2002) in Israel, suggesting several glacial refuges south of the Caucasus.

The species was recorded from Cyprus by Cheylan (1991, as abbotti) who cited Spitzenberger (1978b), but she documented only M. musculus, and in a more exhaustive study of Mus populations from the Aegean and Ionian Isls, Chondropoulos et al. (1995) identified M. musculus domesticus as the only Mus now living on Cyprus. However, Cucchi et al. (2002) demonstrate that M. m. domesticus and M. macedonicus now live on Cyprus and have been there from at least the 9^th millenium BC. Whether the latter is a survivor from an indigenous Pleistocene fauna on Cyprus or introduced inadvertently by the first agro-pastoral societies migrating from the mainland is unknown (Cucchi et al., 2002).

Fossil history of indigenous Israeli M. macedonicus (discussed as spretoides) relative to colonization and origin of commensalism in M. musculus reported by Auffray et al. (1988, 1990b). Mus macedonicus now occurs in the Levantine region, has been there since at least the late Acheulian (late middle Pleistocene), 160,000 years ago (Tchernov, 1992, 1996), and may have been present by the early Pleistocene, 1.4 million years ago (Tchernov, 1996, as M. cf. macedonicus). Bate (1942b) described M. camini from late Pleistocene (Acheulian segment of the Palaeolithic) Tabun Cave deposits in Palestine, but Tchernov (1968, 1986) identified it as an ancient part of the molar variation within the range shown by the chronocline of hundreds of specimens of identified as M. musculus found in sediments from the Acheulian to present in Israel. Reexamination of Tchernov’s material revealed two lineages (Auffray et al., 1988). The oldest is represented by specimens from late Pleistocene Achulian sediments to the youngest level surveyed, which is about 10,000 years old; these samples are M. macedonicus, which lived in the Levant even earlier (Tchernov, 1996) and occurs there today (Auffray et al., 1990b). The other lineage represents M. musculus, which was found only in the youngest level, indicating recent colonization of the Levant by the house mouse no older than about 10,000 years ago. Molars of camini come from middle and late Pleistocene levels in Tabun Cave and likely represent M. macedonicus as implied by Tchernov (1996).