Spremembe v avifavni Kozjanskega parka med letoma 1999 in 2010: velik upad števila travniških ptic/ Changes in the avifauna of Kozjansko Park between 1999 and 2010: a large decline in the number of grassland birds

Abstract In the 11 years between 1999 and 2010, certain groups of birds inhabiting Kozjansko Regional Park underwent a moderate or large decline. Composite indices for indicator species of different habitat types showed an increase of generalist species (composite index 108.3), a moderate decline of forest species (composite index 76.6) and species of extensively managed orchards (composite index 76.4), and a large decline of farmland (composite index 62.8) and grassland species (composite index 8.7). Our study was based on a census using line transects with an inner and outer belt. Randomly distributed line transects with a total length of 60.8 km were surveyed using the same method both in 1999 and 2010. The decline of farmland species mirrors the population trend of this group at the national level. The study area is protected by multiple nature conservation mechanisms. It is protected as a regional park and partly as a Natura 2000 site. These mechanisms, however, do not seem to be functioning here. We believe the large decline of grassland species is a consequence of agricultural policy, which favours a decrease of extensively managed grasslands.