EN
Winter bird communities in a managed mixed oak-pine forest (Niepołomice Forest, southern Poland) were studied during winters the 1996/1997, 1998/1999, and 2000/2001 using the line-transect method. The transect (9.5 km long, 100 m wide) was conducted through three habitats: forest edge, mature, and young stands. The authors noted 5,764 individuals within the transect belonging to 33 bird species. The largest number of species was noted in mature stands – 27 (mean density: 34.0 inds/10 ha), then at the forest edge – 24 (19.4 inds/10 ha), and 18 species in young stands (25.2 inds/10 ha). The density of birds varied between winters and decreased during their course. The density of plant-eaters was significantly lower than that of invertebrate-eaters, but the total biomass of these groups did not differ. Plant-eater biomass was significantly higher in mature stands and at the forest edge than in young stands. Invertebrate-eater density was considerably lower at the forest edge, but the biomass of this trophic guild did not differ significantly among habitats. Plant-eater biomass was significantly lower during winter 1998/1999 and it is supposed that this variation in plant-eater density affects the most total variation in bird communities in the Niepołomice Forest. The authors’ results indicate that old stands are probably the most favourable habitat for some small birds in winter.