High breeding performance of European Rollers Coracias garrulus in heterogeneous farmland habitat in southern Hungary

Capsule Rollers showed slightly higher breeding performance in farmland mosaics than in natural grasslands in southern Hungary, where both habitats were supplied with nest-boxes. Aim To establish which factors affect Rollers' breeding success in agricultural and their more traditional grassland habitats. Methods Rollers' reproductive success in farmland mosaics and grassland habitats were compared. Laying date, clutch size, feeding rate, as well as prey abundance and diversity, as estimated by sweep netting and pitfall trapping, were evaluated. Their effects on breeding performance were analysed by generalized linear models. Results In the agricultural habitat Rollers showed an even higher reproductive output than in their traditional habitat of natural grassland. Prey composition showed differences between the two habitats, with the lower abundance of orthopterans in farmland mosaics being substituted by the higher abundance of coleopterans and the diversity of arthropods (Orthoptera, Coleoptera, Heteroptera, Arachnida, Hymenoptera, Lepidoptera, Diptera, Homoptera, Mantidae, Myrmeleonidae and Odonata). Conclusion Rollers can reproduce well where good quality resources are available, even outside of their typical habitat, where nest-box erection schemes may benefit this threatened species.