Land-use practices have changed markedly in the Czech Republic, and in other central and eastern European countries, during the 20th century (Lipský 1995, Sklenička 2002). In the last few decades in particular, changes in land-use have been accompanied by changes in the extent of all major landscape types. The amount of arable land has declined as fields in montane and submontane areas were abandoned after the Second World War, when three million people were translocated from areas near state borders (Sonka 2002). As a result, forests started to regenerate on these areas (Pokorný et al. 2005). At the same time, cattle grazing was prohibited within the forested areas and the rotation period increased (Konvička et al. 2004). Forest invasion was enhanced during the transformation of the Czech economy starting in 1989; subsidies in agriculture dropped to a minimum thus restricting arable land to highly productive areas (Sklenička 2002). All of these processes have contributed to the maturation of Czech forests during the last decades (Anon. 2005). Although such large environmental changes would be expected to have an effect on bird populations, large-scale studies of population changes in birds in central and eastern European countries are rather scarce. The explanatory power of existing small-scale studies (Wesołowski & Tomiałojc 1997, Stříteský & Krist 2004) is limited, and does not explain population changes of birds at larger spatial scales (Holmes & Sherry 1988). Moreover, results at regional and local