In 1986-1993 the communities of vertebrates and factors influencing their structure and diversity were studied in the area of the Biosphere Reserve Poľana. A total of 18 fish species, 10 amphibians, 9 reptiles, 161 birds and 37 mammals species were found in this area. The anthropogenic and natural factors were classified for the typical habitats in the mountain protected areas. Positive and negative examples of affecting populations were outlined. Among negative factors the forest management (clearcuttings, forest tracks), liquidation of dispersed greenery, pasture, burning and mowing of meadows, regulation and contamination of water bodies and streams, drying out of wetlands, poaching and recreation, appeared to be of the greatest importance. Creation of new habitats in cultivated and natural landscape and their influence on the breeding bird communities were discussed. The examples of this were illustrated by the foundation of the small pond in agricultural landscape near Očová and recreation sites in the natural spruce forests of the Poľana Mts.)