The possible impact of climate change on the future distributions and numbers of waders on Britain's non-estuarine coast

The relationship between weather and wader distributions on non-estuarine coasts is described and used to predict how future wader distributions may respond to climate change. The distributions of eight out of nine species of wader commonly wintering on the non-estuarine coasts of Britain altered between two similar surveys, in 1984/85 and 1997/98, that covered 78% and 38% of Britain's 12 594 km of non-estuarine coastline, respectively. These eight species moved at least in part either eastwards along the winter isotherms or northwards. These changes in distribution broadly coincide with a distributional shift towards the species' respective breeding grounds and are correlated with the local winter weather over the period: increasingly mild extreme temperatures and changes in mean rainfall, mean wind speed and wind-chill. Based on the scenarios for Britain's climate in 2020 and 2080, it is predicted that the distributions of the waders will move away from the west. The non-estuarine coasts of Britain hold particularly high proportions of the international flyway populations of Ringed Plover Charadrius hiaticula , Sanderling Calidris alba , Purple Sandpiper Calidris maritima and Ruddy Turnstone Arenaria interpres that are all expected to show continuing decline to 2080. Overwintering waders appear to be good indicators of the effects of climate change.