On a walk along Tan-y-Bwlch beach today, we saw a huge group (at least 60, probably more) - of House Martins in flight, and apparently feeding, swooping over the Ystwyth at the point where it turns inland from the beach, and up to the first bend. We guess this was the same group that you reported on in your posting of 22 April. As you commented, House Martins are a common sight in this area, but in the past they've been in fairly small numbers, so it's interesting to speculate on what has brought them here en masse this year.
Among other sightings, there were three Whimbrel at the shoreline, in company with 14 Oystercatchers, and a Wheatear towards the south end of the beach.
Helen Ougham and Sid Thomas