Habitat specialization of birds in the Czech Republic: comparison of objective measures with expert opinion

CAPSULE: Expert-based classification of bird species as habitat specialists and as generalists agrees with objective measures of species’ habitat requirements based on large-scale monitoring data. AIMS: To compare habitat specialization of 137 common bird species breeding in the Czech Republic using three different measures and to test their relationships to species’ abundance and habitat associations. METHODS: Data on bird abundance and surveyed habitats were collected through a standardized monitoring scheme of common breeding species in the Czech Republic. From these data we calculated a quantitative species specialization index (SSI). Canonical correspondence analysis (CCA) was applied to calculate species’ habitat niche breadth and the level of association of each species to the main habitats. A panel of 11 local bird experts classified each species as habitat generalist or habitat specialist. RESULTS: Species classified as habitat specialists by expert opinion showed higher habit...