Southern Birch Mouse

The southern birch mouse is a very small, long-tailed rodent with a narrow blackish stripe down the spine, often bordered by paler lines. The remaining upperparts are buff or grey-brown and the belly is pale. Its tail is substantially longer than the body and assists balance while the animal threads through grasses. It resembles the northern birch mouse, but favours more open, drier country and requires careful regional identification. (Wikipedia, southern birch mouse account)

This birch mouse occupies steppe, dry meadow and other grassy habitats from southeastern Europe across western and Central Asia. It is mostly active at night, taking seeds and small invertebrates while moving through dense ground vegetation. A long winter hibernation is spent in a sheltered nest, and breeding takes place during the warmer season. The species account opened for this entry did not document a Mongolian locality or Mongolia-specific timing, so neither a viewing site nor precise local calendar is offered. (Wikipedia, southern birch mouse account)