Additional squares in Scottish Woodlands and English Uplands
In 2009, for the first time, results from additional BBS-style surveys in under-represented habitats were included in the BBS trends.
Counts made by BBS volunteers provide valuable information about many habitats and species, but remote areas often have lower levels of volunteer coverage. To boost the BBS sample size, a programme has been developed to enhance survey coverage in upland areas of England, and in Scottish woodlands. Professional fieldworkers have carried out surveys as part of the Upland Breeding Bird Survey (UBBS) in upland areas of England from 2006-2010, funded by Natural England and the RSPB to improve monitoring of upland bird species. Using standard BBS methods, 1-km squares are surveyed in pairs (one randomly located main square plus one adjacent square) in order to make best use of the surveyor’s time in the field.
The approach of collecting data from adjacent squares was rolled out to core BBS volunteers in upland areas in 2010, and the statistical methods developed for the UBBS will be used to incorporate this information.
In Scotland, additional 1-km squares in wooded areas have been surveyed using standard BBS methods by mainly professional fieldworkers from 2007 to 2009, funded by the Forestry Commission Scotland and Scottish Natural Heritage to improve monitoring of some of the less common woodland bird species in Scotland.
In 2009, the data collected by these additional surveys in English uplands and Scottish woodlands were incorporated into the English and Scottish BBS trends respectively, resulting in improved species coverage, larger sample sizes for all species, and hence more robust trends. The non-random habitat selection of these squares was taken into account during analysis. In 2009, the additional results were not included in the overall UK trends.