The last remnants of pristine forests in Europe, especially in the nemoral belt of deciduous and mixed deciduous coniferous trees, are unique for understanding the history, composition and structure of plant and animal communities. This is especially true for the Białowieża forest, NE Poland. The biogeographical history of emblematic forest clades of birds, e.g. woodpeckers, tits and nuthatches, is analyzed from molecular phylogenies which allow to determine their pace and mode of origination and differentiation. The flyways which connect temperate and tropical realms played a major role in the origination and differentiation of many extant lineages. Then, large differences in the structure of bird communities between North American and European forests are discussed and explained in the light of the geographic configuration of major land masses and past climatic changes and upheavals throughout the Neogene. From long term in depth studies in this forest, the composition and structure of bird communities may be used as references for understanding and measuring the processes and mechanisms of change in communities of the western managed forests.