39 Republic of Ireland 39 Introduction Great Britain and Ireland share a number of attributes which contribute to their importance for wintering waterbirds. These include their geographical position along the major Palearctic/ temperate flyways, ameliorative conditions due to the Gulf Stream maintaining relatively ice-free feeding habitats, and a relative abundance of wetlands. Despite accounting for 55% of the substrata of the coast- line (‘cliff’ (5%), ‘rock’ (41%) and ‘stone’ (9%): Neilson & Costello 1999), non-estuarine coasts have been relatively neglected by successive waterbird monitoring programmes. In the Republic of Ireland, such surveys have been undertaken in the mid-1970s (Hutchinson 1979), mid-1980s (Sheppard 1993) and annually since 1994 (Delany 1996, 1997, Colhoun 1999, 2000, 2001a, 2001b, 2002). Coverage, however, has been heavily biased in favour of more readily definable and discrete wetland habitats including inland lakes and estuar- ies. The first national assessment of the importance of non- estuarine habitats for waders was undertaken in December 1987 and published in Green et al. (1988) and Kirby et al. (1991). This followed several years after the 1984/85 Winter Shorebird Count (WSC) which took place in Britain and Northern Ireland and which revealed significant concentra- tions of wintering waders on this habitat (Moser 1987). A total of 30% of Northern Ireland’s wintering waders, for example, were found on the non-estuarine coast (Moser & Summers 1987, Moser & Prŷs-Jones 1988). Over 18,500 waders were recorded on 563 km of coast- line in the December 1987 survey in the Republic of Ireland (Green et al. 1988). Coverage was, however, restricted chiefly to the north-west and west coasts, including almost entire coverage of counties Leitrim, Sligo and Clare and partial coverage of the coasts of Donegal and Kerry. The entire coasts of Mayo, Galway and all southern and eastern counties (from Cork to Louth) were not visited. Despite this limited coverage, the study provided valuable information on the distribution of key waders species associated with this habitat in Ireland. These provided useful in revisions of population estimates for some species as adopted by Sheppard (1993) and currently in use (e.g. Colhoun 2002). The organisation of an international survey of waders and other waterbirds on non-estuarine coasts over the winter of 1997/98, co-ordinated by the British Trust for Ornithology (BTO), provided an opportunity for the implementation of a further and more complete survey in the Republic of Ireland. This paper presents the results of the Non-Estuarine Coastal Waterbird Survey in the Republic of Ireland (Ireland-NEWS), reporting exclusively on wader populations and revising Wader populations on non-estuarine coasts in the Republic of Ireland: results of the 1997/98 Non-Estuarine Coastal Waterbird Survey (Ireland-NEWS) K. Colhoun, G. Austin & S. Newton Colhoun, K., Austin , G. & Newton, S. 2008. Wader populations on non-estuarine coasts in the Republic of Ireland: results of the 1997/98 Non-Estuarine Coastal Waterbird Survey (Ireland-NEWS). pp. 39–48. In: N.H.K. Burton, M.M. Rehfisch, D.A. Stroud & C.J. Spray (eds). The European Non-Estuarine Coastal Waterbird Survey. International Wader Studies 18. International Wader Study Group, Thetford, UK. A survey of waders on non-estuarine coasts in the Republic of Ireland was carried out in December 1997 and January 1998 as part of the Europe-wide Non-Estuarine Coastal Waterbird Survey (Europe-NEWS). Almost 1,100 km of coast, equivalent to around 53% of the entire non-estuarine coastal length as defined for survey, was covered. Waders represented 65% of the waterbirds recorded; most numerous were Eurasian Oystercatcher Hae- matopus ostralegus (10,552), Eurasian Golden Plover Pluvialis apricaria (9,895), Northern Lapwing Vanellus vanellus (6,643) and Eurasian Curlew Numenius arquata (6,555). Eurasian Oystercatcher and Eurasian Curlew were the most frequently encountered species, occurring in 87% and 63% of all surveyed sectors, respectively. Total numbers of the target species typically associated with non-estuarine coasts include Common Ringed Plover Charadrius hiaticula (2,750), Ruddy Turnstone Arenaria interpres (2,226), Sanderling Calidris alba (915) and Purple Sandpiper C. maritima (447). Bootstrapped population estimates for these species further highlight their reliance on non-estuarine coastal habitats. Respectively these were 7,734, 5,956, 4,186 and 2,700. Comparison of totals counted by Ireland-NEWS expressed as a proportion of the totals recorded during this and the January Irish Wetland Bird Survey (I-WeBS) Core Counts showed that over 45% of each were recorded at Ireland-NEWS sectors alone. Comparison of densities suggests that numbers of all four species declined by between 33% and 81% over the 10-year period since the last survey. Length of non-estuarine coast Coverage Representative of Winter Population estimate Reliability 2,077 km 53.0% Whole country 1997/98 Statistical extrapolation Good