Investigations were done in 2008 during August–November in northern Lithuania: the Kamanos Strict Nature Reserve (SNR), the Žagarė Regional Park (RP) and in eight other administrative districts. Small mammals were snap-trapped using lines from 15 to 50 snap traps. In total, 1 149 small mammals of 13 species were trapped. Bank vole (Myodes glareolus) was the dominant species (29.3%) of the total catch, while yellow-necked mouse (Apodemus flavicollis) and striped field mouse (Apodemus agrarius) were subdominants (19.9% and 13.8%, respectively). The rarest species with a less than 2% share were as follows: water shrew (Neomys fodiens), house mouse (Mus musculus), pygmy field mouse (Apodemus uralensis), harvest mouse (Micromys minutus) and northern birch mouse (Sicista betulina). The forest and meadow habitats were dominated by bank vole and subdominated by yellow-necked mouse (35.7% and 19.9% of total catch in the mentioned habitats), while in agricultural habitats dominant was common vole (Microtus arvalis / rossiaemeridionalis) and subdominant was striped field mouse (32.4% and 24.2%). All 13 small mammal species were trapped in forest and meadow habitats, but only nine species were trapped in agricultural habitats. Pygmy field mice were recorded in the Žagarė RP and the Kamanos SNR only. Northern birch mouse was trapped in Rokiškis municipality, near the Juodupė village.

Keywords: northern Lithuania, small mammals, species diversity, relatively abundance