Penetration of mammals over urban green spaces in Warsaw

able shelters determ ines the occurrence or absence of field mice in an urban green space. The number of shelters may also be assumed to de term ine population numbers. The large number of shelters rich lu x uriant vegetation and in the surface layer of the soil, and the very rare visits to the area by dog's and humans, justify the assumption that the cem etery area is among the most abundant in numbers of A. agrarius in Warsaw.