Estimating effects of arable land-use intensity on farmland birds using joint species modelling

The study compares bird numbers for a set of farmland bird species in landscapes/sites differing in agricultural land use and amount of semi-natural habitats. The dataset is comprised of bird counts and agricultural habitat characteristics from a set of 1km radius circular landscapes distributed in the most to medium productive regions in Scania (southern-most province of Sweden).

Study sites (landscapes) where selected to maximise orthogonality in the habitat characteristics. Bird counts in each landscape where made for 5 min. at 11 – 16 points distributed in a 4 by 4 grid (approx. 400 m between points; half the points, “columns” 1 and 3, where moved to nearest field border; points more than 50 m outside farmland where discarded; points that could not be accessed (gardens etc.) where moved to nearest access point).