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Abstract from BTO Research Report No 234:

Henderson, I.G., Wilson, A.M. & Steele,D.

Population estimates & habitat associations of breeding waders in Norhtern Ireland, 1999: The results of an extensive survey.

1. A re-survey of 106 tetrads (2 km x 2 km squares) in Northern Ireland, each previously surveyed in 1987 (then 146 tetrads in total), was conducted between April and June of 1999 to survey breeding populations of Snipe, Lapwing, Curlew and Redshank. Most observers (62%) surveyed their allocated tetrads on two occasions over this period, recording both birds and habitat information.

2. The survey revealed breeding population declines of over 50% for Lapwing, Curlew and possibly Redshank and over 30% for Snipe. Snipe densities may have been underestimated in 1999 compared to 1987, but a shallow decline in this species is still suspected over the interim period.

3. In general, few birds of any species were recorded on improved pastures or winter cereals. Lapwings, which were recorded on a wider range of habitats than other species, were recorded frequently on cultivated land, but only on late developing spring crops, stubbles or bare soil. Winter cereals and improved grasslands were avoided by this species. Breeding Lapwings were particularly scarce in the eastern counties of Northern Ireland.

4. Snipe were typically associated with bog/mire and marshy habitats, and their apparent decline may be linked to widespread losses of these habitats across Northern Ireland and particularly on farmland, since no clear range contraction was observed. Very few Snipe were recorded on improved grasslands.

5. Almost all Curlew were associated with bog/mire and unimproved grassland. Population declines, particularly in County Antrim, appear to represent a continuing range contraction from the eastern region of Northern Ireland. Previous studies have identified predation as possible proximate cause of the Curlew decline, but strong relationships with habitat composition, such as grassland mosaics are also emphasised in further studies within the UK. Curlew also avoided improved grasslands (relative to its availability). As with Snipe and Lapwing, marshy ground or surface water (including ponds or lakes) was a component of virtually all tetrads in which Curlew were found, but was present in less than half of the tetrads in which no waders were found.

6. Only five Redshank pairs (nine birds) were recorded in the survey and their scarcity and localised distribution restricts the power of the current large-scale, random tetrad design of survey to generate population estimates with any degree of precision. Consequently, a thorough census of known key wader sites in Northern Ireland is recommended for all species above but especially for Redshank.

7. The population declines of Lapwing, Curlew and Redshank in Northern Ireland exceed the alert level criteria for red listed species of conservation concern, that is, a greater than 50% decline in 25 years.

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