Abundance of breeding farmland birds on arable and set-aside fields at forest edges

• Published in: Ecography (Copenhagen) Vol. 17; no. 2; pp. 147 - 152
• Main Authors: Berg, Aa, Paert, T
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-06-1994; Munksgaard International Publishers; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Aves; Aviculture; Biological and medical sciences; Bird nesting; Birds; Deciduous forests; Ditches; Edge effects; Farmlands; Forest habitats; Fundamental and applied biological sciences. Psychology; Land diversion; Predation; Synecology; Terrestrial ecosystems; Sweden; Europe; Nesting; Cultivated field; Forests; Risk; Vertebrata; Reduction; Ecotone; Farm land set-aside; Predation; Aves; Vegetation structure; Ecological abundance; Fallow
• ISSN: 0906-7590; 1600-0587
• DOI: 10.1111/j.1600-0587.1994.tb00087.x

The aim with this study was to investigate whether abundance of farmland birds on fields at forest edges were associated with (i) type of field (young set-aside vs arable fields), (ii) the length and structure of the field-forest edge zone, and/or (iii) with residual habitats such as habitat islands, ditches, roads etc. Twenty-eight farmland bird species (all nesting and/or foraging on open fields) were censused during the breeding season on 48 plots (open fields with adjoining forest edges) in the central parts of Sweden, covering a total area of 595 ha. Skylark Alauda arvensis, linnet Carduelis cannabina, whitethroat Sylvia communis and whinchat Saxicola rubetra were found in significantly higher numbers in set-aside-plots than cereal ones. However, the most important factor explaining variation in the abundance of most species was the structure of the field-forest ecotone, with the length of shrubby southern deciduous forest edges being the most important factor in 7 of the species. Mixed forest edges seemed to be of some importance for the abundance of 3 species, while associations between abundance and length of the other deciduous and coniferous field-forest ecotones only were significant for one species each. Skylarks, white wagtails Motacilla alba and whinchats were positively associated to ditches and yellowhammers Emberiza citrinella and linnets were significantly associated to habitat islands. The observed preferences for set-asides and shrubby field forest edges are suggested to be results of reduced predation risk and increased food abundance.