Population increase of forest birds in the Czech Republic between 1982 and 2003

Abstract

Capsule: Populations of most forest bird species increased between 1982 and 2003, probably due to increased forest cover and changes in forest age-class composition. Aims: To determine population changes of forest birds in the Czech Republic and to determine their possible causes. Methods: Population data were collected via the Breeding Bird Monitoring Programme, which is based on skilled volunteers counting birds at point transects using a standardized technique. Population trends and indices for the period 1982-2003 were calculated for 47 species using log-linear models. Published data on development of forest cover and forest age composition in the Czech Republic were used to indicate environmental change over the same period. Results: Populations of most forest species increased between 1982 and 2003. There was also an increase in forest cover and an increase in the proportion of older forest age-classes. The increase in forest specialist birds was positively correlated with the average increase in forest coverage. Conclusions: The populations of Czech forest birds have increased in the last two decades. This contrasts with widely reported declines of farmland bird populations throughout Europe. The correlation between populations of specialized forest species and extent of forest habitat suggests that changes in land-use are an important factor. However, increasing cover of mature forests could have a similar effect on the populations of specialist species. © 2007 British Trust for Ornithology.