ON THE BIRD POPULATION OF THE SPRUCE FOREST COMMUNITY IN SLOVAKIA.*

The bird population of the Norway spruce communities was studied for seven years in Slovakia, by quadrat counts and transects. The work was done between 300 and 1700 metres a.s.l. mostly in pure stands.
A total of 63 species of birds in 46 genera and 21 families was found. Of these, 43% were resident, 57% migrant and vagrant. The zoogeographical origin of the species is considered and they are tabulated according to altitudinal distribution. They are divided into food groups—herbivores, mixed feeders, insectivores and carnivores—and into five strata or zones according to the food-niches.
The species populations are listed by numbers of individuals and weights in grams per 100 hectares of spruce forest—totals about 1300 birds weighing about 48,000 grams. The results are compared with data from other countries and communities. Both density and biomass are lower than in other forest communities in Slovakia, the highest being in the bottomland forests around the Danube.
Coal Tit, Chaffinch and Song Thrush (i.e. mixed feeders) are the species forming over 5% of the population and its biomass. The next most important group is the herbivores and the third insectivores.