Relationship between land-use intensity and species richness and abundance of birds in Hungary

When Hungary, together with nine other central and eastern European countries. enters the European Union in 2004 two major threats will arise to the birds inhabiting agricultural landscapes. Marginal agricultural land may be abandoned, while the remaining area may suffer from intensification. To assess the effects of these threats breeding birds were monitored in abandoned, extensively and intensively used vineyards and grasslands in Hungary using point counts to determine species richness and density. Species numbers and bird density were highest in extensively used vineyard:. while bird diversity was highest in abandoned vineyards. Abandoned vineyards were rich in species and individuals. mainly woodland specie:;. whereas intensively used vineyards had both fewer species and individuals than the other two vineyard types. In grassland, four management types were distinguished, abandoned, extensively, intensively grazed and both intensively grazed and fertilised grassland. Extensive grassland harboured most species, bird density and diversity being highest at the abandoned site which was covered by bushes and contained many non-grassland species. Intensively grazed fields had lower species numbers, lower density and diversity than extensively grazed grassland but were still much more species rich and diverse than the fertilised fields. Our results suggest that extensively used farmland holds the highest diversity and abundance of farmland birds. Conservation efforts aimed at farmland birds should therefore focus on maintaining extensive farming systems. (C) 2004 Elsevier B.V. All rights reserved.