Machair research

The machair and blackland habitats of the Uists support the largest concentrations of breeding waders in the UK.  The BTO has been instrumental in monitoring Uist waders since the early 1980s. Observed declines between 1983 and 2000 on South Uist and Benbecula, reported by extensive surveys of the machair, were argued to be largely due to predation of clutches of eggs by hedgehogs. Consequently, by 2003 a programme of hedgehog removal, as funded by SNH through the Uist Wader Project (UWP), had begun and is ongoing.  There is concern that the numbers of some species have not recovered however, suggesting that other factors are involved in limiting wader numbers (e.g. other predators; changes in land use or vegetation).

BTO Scotland took the lead in compiling data from breeding surveys of waders carried out overCultivated machair, Berneray by John Calladine consecutive years dating from the 1980s, 1990s and 2000s for four areas of machair on North Uist and Benbecula, which demonstrated that declines in some species (e.g. Lapwing and Dunlin) had been reported despite hedgehogs being absent or rare at these sites. We have subsequently carried out collaborative research to look at associations between machair characteristics and the abundance of breeding waders in areas where hedgehogs are considered to be absent and how these have changed since the 1980s.  BTO Scotland is currently contracted by SNH to lead a consortium (including the James Hutton Institute and MacArthur Green Ltd) to provide specialist scientific advice for a plan of research on Uist waders through to 2014 and is advising on the 2012 fieldwork.

BTO Scotland science in this area cuts across several of the BTO research themes, including monitoring and multi-scale habitats.

Further reading:

Fuller, R.J., Reed, T.M., Buxton, N.E., Webb, A., Williams, T.D. & Pienkowski, M.W. (1986).  Populations of breeding waders (Charadrii) and their habitats on the crofting lands of the Outer Hebrides.  Biological Conservation 37: 333-361.

Fuller, R.J. & Jackson, D.B. (1999).  Changes in populations of breeding waders on the machair of North Uist, Scotland, 1983 1998.  Wader Study Group Bulletin 90: 47-55.

Jackson, D.B., Fuller, R.J. & Campbell, S.T. (2004)  Long-term population changes among breeding shorebirds in the Outer Hebrides, Scotland, in relation to introduced hedgehogs (Erinaceus europaeus).  Biological Conservation 117: 151-166.

Fuller, R.J., Humphreys, E.M., Wilson, J.D., Hoccum, D. & Calladine, J.C. 2010. Changes in the breeding wader populations of the machair of the Western Isles, Scotland, between 2000 and 2007. Bird Study 57:121-124. (http://www.tandfonline.com/doi/abs/10.1080/00063650903196893)

Calladine, J., Fuller, R. & Humphreys, L. 2011. A survey of population changes in breeding waders on machair in Benbecula and North Uist: Annual surveys in 2008-2010 and changes since the mid-1980s. Scottish Natural Heritage commissioned report 408. http://www.snh.org.uk/pdfs/publications/commissioned_reports/408.pdf

Staff contacts: John Calladine and Liz Humphreys.