In May of this year BSG Ecology deployed a bat detector on Ramsey (along with Skomer and Skokholm) to monitor seasonal variation in bat encounter rates and species diversity on the Pembrokeshire islands
Each week we download the data and send it across to the BSG team. They will analyse it fully later this year and produce a report on their finding in winter 2014/15. I have to admit to being slightly reticent at first that we would find any bats bar the odd pipistrelle but this soon changed when Matt and Rachel from BSG took a quick peek at some of the early data. I am now quite happy to eat my words as we have logged a minimum of 6 different species of bat on the island with the prospect of more to come!
Greater horseshoe bat, common and soprano pipistrelle, noctule, brown long-eared and one of the myotis species have all been recorded in varying numbers. The common pipistelles are nightly and the greater horseshoes are recorded most weeks. Noctules have been present sporadically since June with the others producing occasional records
There might well be more to come when analysed fully and with migration season upon us again it will be very interesting to see what else the island can turn up.
The data will also be of interest in that there is little baseline information concerning the bat fauna of the Pembrokeshire islands, so it will be good to fill a gap in our current knowledge. Ramsey is well known for it's high invertebrate populations (e.g. beetles and moths) so this is one possible reason that bats are finding the island so attractive. The pipistrelles are probably using the old barn and with bats being seen coming out of one of our sea caves earlier in the season it will be fascinating to see the final results of this work.
For more general information on bats see the excellent Bat Conservation Trust website
The BSG kit comprises an Anabat recording device which uses Analook software to produce sonograms of the bats calls. This is a typical greater horseshoe back sonogram with the call peaking at 80kHz
The noctule bat produces a very different sonogram and calls at a much lower frequency