Population changes of common breeding birds in the Czech Republic from 1982 to 2013: An analysis using multispecies indicators
Abstract
Long-term monitoring of bird populations delivers information on mechanisms of population regulation as well as early warning signals for conservation practice. In the Czech Republic, such data are collected within the Breeding Bird Monitoring Programme.
For the purpose of this study, we used data covering 85 common bird species obtained in the period 1982-2013. We aim to describe population trajectories of 14 species groups defined by habitat use, habitat specialization, European breeding distribution and legal protection status.
We employed the multispecies indicator approach by calculating geometric mean of population indices across species in a given group expressed in % relative to the reference year (1982). The indicator containing all species included in this study did not change significantly over the focal time period.
However, particular species groups showed divergent temporal trajectories. Habitat specialists declined, particularly those occurring in open habitats, and the forest as well as urban specialists declined too.
By contrast, habitat generalists increased and the pattern was driven by originally forest species recently colonizing human settlements. The results indicate that bird populations are rather affected by land use change than by climate change.
Statutory protection does not seem to be able to cope with these drivers effectively, albeit many protected species have increasing populations.