The importance of farmland for Ortolan Buntings nesting on raised peat bogs

The majority of the Norwegian population of the endangered Ortolan Bunting, Emberiza hortulana, breeds on raised peat bogs. I studied whether their breeding site selection was affected by the availability of another habitat (farmland) close to bogs. At the landscape level, Ortolan Buntings always chose peat bogs that had farmland less than or equal to 50 m away. At the individual peat bog level, Ortolan Buntings had territories in those parts of the bog that were closest to farmland, and territories were usually less than or equal to 100 m from farmland. These results indicate that bog-breeding Ortolan Buntings require farmland in close proximity to their territories. This conclusion was further supported by observations at the behavioral level. Ortolan Buntings were frequently seen flying between territories on the peat bogs and adjacent farmland (oat fields), often returning with food in the bill. I also analysed the distribution of Ortolan Buntings in relation to peat bog size, availability of different bog microhabitats, and human use of peat bogs (peat extraction), but the effect of distance to farmland remained significant also in multiple analyses. Ortolan Buntings apparently do not have the classical all-purpose territory typical of most passerine birds, but have more or less separated nesting and feeding areas. I discuss possible reasons for this pattern and also the conservation implications of the habitat selection of the Ortolan Bunting.