Greater Horseshoe Bats © Can Stock Photo, remus20
Earlier this summer we had the loan of a bat detector from the Devon Wildlife Trust, which was left in Treragin Wood for three days. More regular readers will realise that Treragin is in Cornwall, but the Devon Greater Horseshoe Bat survey includes areas of East Cornwall close to known breeding sites, and we just squeaked in.
Treragin bat records
My first fear was that I had set up the detector incorrectly, and that there would be no records, but thankfully that was not the case. The results were released recently, and showed a total of 57 bats flying past during the three days. Pipistrelles were the most common, but a single record for a Daubenton’s bat was a slight surprise. They like still open water, but then again like many species they also like to roost in old mine shafts and workings. And there are plenty of those around Treragin! The Lesser Horseshoe bat is also quite rare, but we have had a stray one in White Cottage before, so that was less unexpected.
I was quite pleased with records, but this was put to shame by a friend, who I had alerted to the bat survey, who had 967 records for his place! That included three passes by the elusive Greater Horseshoe bat. He has a smallholding with old species rich flower meadows, a stream and lots of mature hedges and surrounding woodland, so ideal bat habitat. I guess it goes to show that Treragin Wood, at a mere 20 years old, still has a way to go to develop a full woodland ecosystem.
Our woods at Holford are also a special place for bats, as they form part of a Special Area of Conservation (SAC) and also a Site of Special Scientific Interest (SSSI). The SAC designation is primarily because the old oak woods in the area host Barbastelle bats. Thanks to volunteer bat surveys we even know which trees in our woods are used as a roost by the Barbastelles. Let’s hope they don’t fall victim to a gale!
Bats love hollows and cracks in old tree trunks
Harrowbarrow Mine chimney, just up the valley from Treragin
We also undertake bat surveys as part of our ecological services, and these are often required for building developments that involve conversions or demolitions. However, bats used to manage without cosy centrally heated attics, and old trees and caves were two of their favoured haunts. Bat numbers have stabilised after many years of decline, and some of this is due to better legal protection of roosts. But as the survey results for Matt’s smallholding emphasise, the surrounding habitats and farmland are at least as, if not more, important. The insects that bats fed on are associated with open water, old species rich flower meadows, and indeed mature native woodlands. Species protection is no substitute for wider countryside conservation. Hopefully Treragin Wood will become a gradually increasingly important part of that jigsaw.
Stephen
