Grasshopper Warbler Locustella naevia breeding habitat in Britain

Capsule Structural aspects were common across a range of different habitat types and there was evidence that this breeding habitat was limited in extent. Aims To characterize Grasshopper Warbler breeding habitat in Britain and to use this assessment to test whether it was limiting the breeding population. Methods In 2005 singing Grasshopper Warblers were surveyed at four groups of sites in southwest Scotland, during four night-time periods through the season, to quantify which period would afford best detection. Breeding habitat characteristics were measured at 210 Grasshopper Warbler singing positions and 210 systematically located comparison sites positioned across 22 sites in England and Scotland. In 2006 tests were conducted using two different procedures to determine whether the preferred breeding habitat was limited. First, by using the 2005 data to map predicted suitable habitat at 15 sites in southwest Scotland before Grasshopper Warblers arrived, and then assessing the extent of actual occupation...