THE EFFECTIVENESS OF NEST-BOX SUPPLEMENTATION FOR THE CONSERVATION OF EUROPEAN ROLLERS (CORACIAS GARRULUS)

Provisioning of artificial nest-boxes proved to be an effective method to make suitable breeding sites for secondary cavity nester birds due to the lack of natural hollows. The European roller (Coracias garrulus) is a threatened bird species in Europe, which suffered a serious decline throughout its breeding range. Changing agricultural practices seem to be the main causes attributed to the shortage of suitable breeding sites. In this study we aimed to investigate which factors affect the occupancy rate of newly provided nest-boxes. Four-year rollers' occupancy data were analysed by generalized linear models. Our results showed that nest-box characteristics (holder type and height above ground) and the presence of conspecifics significantly influenced rollers' nest-box occupancy. We conclude that nest-box visibility, height and the presence of conspecifics should also be considered when starting a nest-box supplementation program to ensure an effective method for the conservation of rollers.