Avian predators often affect the abundance of their prey, but studies have shown that the opposite also occurs. This study focuses on prey density as the possible cause of Montagu’s harrier’s (Circus pygargus) habitat switch on Öland. After analysing data from satellite transmitters and other available data, main hunting grounds showed to be open landscape and fields. However, the prey density was not higher in these habitats compared to other habitat types. A discussion is made about available data, the difference between prey density, prey availability and which scenario that attracts Montagu’s harriers the most to certain habitat types. Some inputs on how to improve the conservation of Montagu’s harriers on Öland is also discussed.