Calabria pine vole

Microtus brachucercus was initially described by Lehmann in 1961 as a subspecies of M. savii, under the name Pitymys savii brachycercus. brachycercus refers to its short tail.^[2] Genetic tests in the Calabrian region found, although similar, the X chromosome is larger than that of samples of M. savii found elsewhere in Italy and the Y chromosome is twice the size, leading Galleni in 1994 to designate M. brachycercus as a separate species.^[1][3]

DNA evidence suggests that M. brachycercus separated from M. savii 0.3 to 0.5 million years ago.^[4] The two species can hybridize, but the male offspring are infertile and do not produce and sperm. The females are fully fertile, however.^[5][6]

M. brachycercus has two subspecies, M. brachycercus niethammericus and M. brachycercus brachycercus.^[7]

The Calabria pine vole is a small vole, weighing about 14 grams (0.49 oz) to 24 grams (0.85 oz).^[2] It is very similar in form to Savi's pine vole (M. savii). It can often be distinguished morphologically by a more open anterior loop in the first lower molar, but this can sometimes be found in Savi's pine vole as well.^[8]

The Calabrian pine vole is found in central and southern Italy, in a wide variety of habitat types.^[7][1] It was first identified from Calabria, in southern Italy, and the extent of its northward range is still being investigated; earlier sources report the distribution as just southern Italy.^[9][8] It is quite common in its range and the population is stable, so it is considered a species of least concern by the IUCN despite its relatively restricted range.^[1]