Evalution of rook deterence by trained raptors

In Burganland in Souther Austria tzhere are rooks breeding in close distance to oganic farmed maize fields. There rooks like feeding on small seedlings and can destroy up to 100% of the maize plants. The government allows detering of rooks with falcons and goshwaks flown by the Burgenländische Falknerbund. The birds are flown before and in the time of seedlings and rooks get dispersed. Aim of the study is to assess the efficiency of this method and to study the movement patterns of the birds including land use patterns.