Habitat selection of Ortolan Buntings Emberiza hortulana on forest clear-cuts in northern Sweden

Julianna Anne Percival,Svein Dale

doi:10.34080/os.v26.22527

Abstract

Ortolan Buntings Emberiza hortulana in Sweden used to occur mainly in farmland. Nowadays, a large proportion of the remaining population is found on forest clear-cuts in northern Sweden. Few studies have identified the types of clear-cuts that Ortolan Buntings prefer and whether these habitats are used for both breeding and foraging. We recorded presence and abundance of ortolan buntings on clear-cuts in Västerbotten County, northern Sweden. We sampled 123 clear-cuts (present N = 48, absent N = 75; total of 93–100 territories) and our results showed that clear-cut size, the number of remaining trees, bare soil percentage (≥10%) and narrow-leaved grass vegetation had a positive influence on ortolan bunting occupancy. The number of territories on clear-cuts was positively related to clear-cut size and number of remaining trees. Proximity to nearby farmland did not influence occupancy on clear-cuts. Behavioural observations indicated that the forest clear-cuts were used for both nesting and feeding. We discuss these results in relation to forest management policies and conservation of the ortolan bunting.

Highlights

The Ortolan Bunting Emberiza hortulana is a long-distance migratory bird currently experiencing large population declines and range contractions across most of Europe (Menz & Arlettaz 2011)
Changes in farming practices and agricultural intensiication has led to widespread habitat loss and deterioration of suitable breeding habitat for both the Ortolan Bunting and farmland species in general and subsequent population declines (Svensson et al 1999, Wretenberg et al 2006, Green & Lindström 2014)
The irst two variables were related to abundance of Ortolan Buntings

Summary

Introduction

The Ortolan Bunting Emberiza hortulana is a long-distance migratory bird currently experiencing large population declines and range contractions across most of Europe (Menz & Arlettaz 2011). Ortolan Buntings were once common in large parts of Sweden. A large proportion of the remaining population is found in northern Sweden, where they are found mostly on forest clear-cuts (Ottvall et al 2008). Based on data from the Swedish breeding bird survey, Ottvall et al (2008) found that abundance of Ortolan Buntings on clear-cuts did not depend on distance from farmland. Clear-cuts used by Ortolan Buntings may provide both breeding and feeding habitat in contrast to the situation in Norway, but detailed knowledge of habitat use and feeding behaviour on clear-cuts in Sweden is lacking

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