Individual study: Effects of managed field borders on grassland birds overwintering on farmland in Clay and Lowndes counties, Mississippi, USA
Smith M.D., Barbour P.J., Burger L.W. Jr. & Dinsmore S.J. (2005) Density and diversity of overwintering birds in managed field borders in Mississippi. Wilson Bulletin, 117, 258-269
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Plant wild bird seed or cover mixture
A replicated, controlled study in February-March 2002-03 on three arable farms in Mississippi, USA (Smith et al. 2005), found that densities of song sparrow Melospiza melodia were significantly higher in field margins seeded with Kobe lespedeza Lespedeza striata and partridge pea Chamaecrista fasciculata, compared to control field margins, when fields bordered blocks (> 30 m) of herbaceous vegetation (31 birds/ha vs. 8 birds/ha) or strips (<30 m) of woodland (38 birds/ha vs. 10 birds/ha), but not when fields bordered herbaceous strips (96 birds/ha vs. 70 birds/ha) or blocks of woodland (25 birds/ha vs. 28 birds/ha). Savannah sparrows Passerculus sandwichensis did not show any such variation, whilst other sparrow species (notably swamp sparrow M. georgiana) were significantly higher in uncultivated margins adjacent to herbaceous blocks (78 birds/ha vs. 19 birds/ha), herbaceous strips (139 birds/ha vs. 30 birds/ha) and wooded blocks (51 birds/ha vs. 12.6 birds/ha). Borders were established in 2000 and were seeded in 2000 and early 2001.