The west coast habitats of the Uists and Benbecula, and islands in the Sound of Harris, hold concentrations of breeding waders that are exceptional both in Scottish and UK contexts. Observed declines in wader populations between 1983 and 2000 on South Uist and Benbecula were argued to be largely due to predation of clutches by hedgehogs, which were first introduced to the islands in 1974. This was, in part, based on the experimental removal of hedgehogs from fenced enclosures in 1998, which resulted in a substantial increase in the combined hatching success of Dunlin, Lapwing, Redshank and Snipe. By 2003, a programme of hedgehog removal, funded by SNH through the Uist Wader Project, had begun and work continues to date under the renamed Uist Wader Research.
There is concern, however, that population numbers of some species of waders have not fully recovered on the Uists. It is highly likely therefore that other factors, in addition to predation by hedgehogs, are limiting wader numbers. In 2011, a consortium (BTO, The James Hutton Institute and MacArthur Green Ltd), under contract to SNH, produced a scoping document that described research options to assess the influence of a range of factors on the breeding wader populations on the Uists’ machair.
During the 2012 breeding season, nest cameras, nest temperature loggers and systematic direct observations are being employed to quantify predation rates and the relative influences of different predators on the breeding attempts by waders in two study areas, one where hedgehogs are largely absent and one where they remain common. Dependent on findings and the efficacy of the methods, it is planned to extend the study across a gradient of hedgehog densities within the Uists and Benbecula in 2013-14. The aims will be to assess the effects of predation (including the contributions by hedgehogs and other predators) on the different wader species, and within different habitats and land uses, to inform ongoing management of machair and predators to conserve the breeding wader assemblage.
Humphreys, E.M., Gilbert, L., Furness, R.W., Littlewood, N., Mitchell, R., Pakeman, R., Fuller, R.J. and Calladine, J. (2012) Scoping report to Uist Wader Research: suggested research programme 2012 – 2014. Scottish Natural Heritage Commissioned Report.
Scottish Natural Heritage, James Hutton Institute, MacArthur Green Ltd.
Scottish Natural Heritage
Staff contact: John Calladine