Individual study: Wildflower areas within revitalized agricultural matrices boost small mammal populations but not breeding Barn Owls
Arlettaz R.L., Krähenbühl M., Almasi B., Roulin A. & Schaub M. (2010) Wildflower areas within revitalized agricultural matrices boost small mammal populations but not breeding Barn Owls. Journal of Ornithology, 151, 553-564
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Plant nectar flower mixture/wildflower strips
A replicated study in 2005 in western Switzerland (Arlettaz et al. 2010) found that small mammal density and species richness were higher in wildflower areas than crops, but wildflower areas were avoided by barn owls Tyto alba. Wildflower areas (two years old, 1 ha) had more small mammal species and individuals (6 species, 458-1285 individuals/ha) compared to crops or meadows (2-5 species, 0-680/ha). In May and July, small mammal densities were significantly higher in wildflower areas (458-1,030 individuals/ha) and winter wheat Triticum aestivum (90-680/ha) than in tobacco Nicotiana tabacum, permanent and intensive meadows and in May maize Zea mays (0-10/ha) (in July the density in maize was 200/ha). In September, density was significantly higher in wildflower areas (1285/ha) than in winter wheat (0), other habitats had intermediate densities (5-60/ha). Barn owls significantly preferred cereal crops relative to availability and avoided wildflower areas and all other crop types. The estimated index of habitat selection by barn owls in order of decreasing preference was wheat, meadows, other crops and lastly wildflower areas. Four arable sites were studied. Small mammal population size was estimated using capture-mark-recapture. Mammal traps were placed at 20 points along two parallel 45 m transects in each habitat and set over three nights and days in May, July and September 2005. Seven breeding male barn owls were radio-tagged from June to September 2005 and hunting or resting locations recorded.