Microtus arvalis is one of the most well-known species of the fauna of small mammals from our country, present starting with the zone of the Danube delta up to the altitude of 1800 m (the Harghita mountains). Regarding the intraspecific taxonomy of this species, Ellerman and the collaborators (1966) recorded the existence of 28 subspecies.
In 1908 Miller described the Microtus arvalis levis subspecies after collecting 3 exemplars in GĂŁgeni, Prahova, this subspecies including the populations of harvest mice from the plain and hill area in Romania. In 1963, Hamar considered on the basis of an exemplary collected in the Bucegi Mountains that the alpine populations belonged to the Microtus arvalis heptneri subspecies. Miller also recorded the subspecies Microtus arvalis angularis, after the material collected in HaĂŸeg, Hunedoara. The latter was recognized by Ellerman and Morrison-Scott, but it wasnât confirmed by the subsequent researches. (Alexandrina Popescu and D. Murariu, 2001)
Taking into account these uncertain data referring to the intraspecific taxonomy of the Microtus arvalis species we consider necessary gathering as many data as possible that could help clarifying some problems of intraspecific taxonomy. | 
