In the bad old days before we had reliable detectors and the only way to identify bats was to catch them, we assumed that this was the largest Whiskered roost in the country. However, once we were able to identify bats without catching them, we realised that there was a colony of Common Pipistrelles that lived in the east end of the main building and in the roof above the dining hall. The building is a former primary school which is now run by Durham county Council for its schools. We inevitably deliver an impromptu talk to the school in residence in which the bats captured on the evening make a star appearance. The survey is not trivial. There are 8 gable ends on the building and then there is the dining hall and the reverse of the building. We usually trap at two of the gables and occasionally send a more agile batworker aloft to catch outside the dining room. We now realise that we need to capture outside the exits on the eastern end of the building to investigate the use by Soprano Pipistrelles
The first is a worrying decline in the number of Whiskered bats. We were counting several hundreds in the 90s, low hundreds until the early years of this decade but we recorded less than 50 this year and last. It really does seem as though the colony is in decline yet we have no idea what is the cause. It would also appear that Common and perhaps Soprano Pipistrelles are expanding into the space once used by the Whiskered bats. Paul Lupton spotted two Brown Long-eared bats emerging from the western gable end this year and this is the first time that this species has been found roosting here. We are not sure if these have been missed by previous observers or whether this is another change in patterns of usage. At this year's count we had 16 observers, most of whom were very experienced. This was barely enough to cover the essential surveys and we could easily have used a dozen more volunteers.
The count is always
held mid week as close as possible to the summer solstice. Please put it
into your diary for next year.
Noel Jackson
