Waterford Breeding Bird Atlas 2006-2011: how many squares

In total, 37 10-km squares have at least some of their land area inside the current Co Waterford administrative boundary. Of these, 25 squares have the majority of their land area in Waterford.

Something like 545 2-km tetrads have land in Waterford, but some along the county border have only tiny amounts of land (<10 ha) in Waterford. Excluding the latter, but for completeness including all coastal tetrads with any amount of land, gives c540 tetrads to target for the Waterford Breeding Atlas. Of these, 478 'full' tetrads, with at least half of their land area in Waterford and with their midpoint above Low Water Mark (LWM), will be the main priority for Timed Tetrad Visits (TTVs).

For the national atlas, likewise only those tetrads whose midpoint is above LWM will be eligible for full, quantitative coverage i.e. TTVs. Other ('partial') tetrads, whose midpoint is below LWM, will not require TTVs for national purposes (though they can be covered by Roving Recorders). However, for the Waterford Breeding Atlas, shorter TTVs will be made to partial tetrads, for local purposes only.

A further complication is that tetrads along the Waterford border with Cork, Tipperary and Kilkenny may have substantial amounts of land (or different habitats) in several counties. For the national atlas, this will require cross-border coverage to ensure representative (unbiased) results. It is likely that Waterford-based fieldworkers will take responsibility for those tetrads, and keep more detailed records for local purposes, highlighting species occurring on the Waterford side.

478 full tetrads mainly (50%+) in Waterford and with their midpoints above LWM (eligible for full Timed Tetrad Visits for national and Waterford atlas coverage);

19 further full tetrads with 15-49% of their land area in Waterford but most of their land area in adjacent counties (either full TTV for national atlas with subdivision of data by county + extra coverage for Waterford atlas, or coverage of Waterford section as a 'partial' tetrad for local purposes);

12 cross-county tetrads with <15% of their land-area in Waterford (probably treated as partial tetrads, with TTVs, for Waterford atlas, and probably not requiring coverage of Waterford section if covered for national atlas);

29 coastal tetrads with their midpoints below LWM (partial tetrads with TTVs for Waterford atlas, TTVs not required for national atlas).

For the Waterford breeding atlas, all 10-km squares and 2-km tetrads will be targeted for coverage some time during 2006-11. As many as possible will be covered during 2007-11 (also contributing to the national atlas), with priority in those years being given to tetrads not already covered in 2006 or 2007. Further priority may also be given to tetrads that were covered in the 1988-91 breeding atlas, to help with assessment of status changes since then.

For the winter seasons (2007/08-10/11), full coverage of tetrads is unlikely to be achieved, but at least 8 tetrads will be covered in each 10-km square (or all tetrads if there are fewer than 8 with their midpoints above LWM).