There has been a cliff colony of House Martins at Aberforest in the 20 years we have lived locally. Most years I had no specific note, but 2002 "seemed plentiful", 05 "lots", 2012 ++, but in 2015 it seemed abandoned, just 1 lone bird. In 2016 & 7 there was little activity in May & June, but c3 nests being visited in July. Numbers seemed up again last year & this seems to have held up this year, though "plentiful" is not the right word.
Of more concern this year is Swallows. None of the local sites where I would expect them on the wires has birds & general sightings by me are much down.
Quite separately, 1 or 2 Redhead Goosanders upstream from the bridge at Newport in the last couple of days are unusual at this time of year.