Population estimates of waders on the non-estuarine coasts of the UK and the Isle of Man during the winter of 1997–98

Abstract

Capsule An updated estimate is presented and major declines in the internationally important populations of several species identified. Aims To provide population estimates of the waders overwintering on the UK and Isle of Man's non-estuarine coasts. Methods UK-NEWS was a repeat of the 1984–85 Winter Shorebird Count (WSC). The WSC results were reanalysed to allow direct comparison with the UK-NEWS results. The new population estimates are provided with bootstrapped confidence intervals. Results UK-NEWS covered 4959 km or 38% of the UK's non-estuarine coastline and recorded over 170 000 waders of 19 species. The new population estimates for the UK's non-estuarine wader species are as follows (values in parentheses are percentages of the East Atlantic Flyway population of each species): 70 790 Oystercatcher Haematopus ostralegus (7%), 24 110 Ringed Plover Charadrius hiaticula (33%), 28 670 Golden Plover Pluvialis apricaria (2%), 2175 Grey Plover Pluvialis squatarola (1%), 41 180 Lapwing Vanellus vanellus (1%), 7625 Knot Calidris canutus (2%), 13 660 Sanderling Calidris alba (11%), 17 220 Purple Sandpiper Calidris maritima (9%), 27 880 Dunlin Calidris alpina (2%), 3670 Bar-tailed Godwit Limosa lapponica (3%), 66 330 Curlew Numenius arquata (16%), 33 820 Redshank Tringa totanus (18%) and 39 560 Turnstone Arenaria interpres (42%). Similarly the Isle of Man held 887 Ringed Plover (1%), 8895 Curlew (2%) and 5220 individuals of the other species. Conclusion Eight species have increased and five have declined in the UK since the 1984–85 survey. We discuss the possible reasons for the declines of Ringed Plover (−15%), Sanderling (−20%), Purple Sandpiper (−21%), Bar-tailed Godwit (−44%) and Turnstone (−16%), species whose numbers on the UK's non-estuarine coasts are internationally important.