After a busy summer of bat tracking last year, the colony of rare barbastelles in the Bovey Valley is providing further interest to scientists. This time, Dr. Orly Razgour, a research fellow from the University of Southampton has started to survey these East Dartmoor bats as part of her European-wide genetic research project on bat responses to global climate change. So far, Orly has been gathering information on barbastelles from Morocco to Sweden and, for a few nights in August, she brought her survey equipment to the Bovey Valley Woods. To support this stage of work, University of Bristol researcher, Andy Carr brought together some of the local volunteers from last years’ radio tracking project.
The group met during the late afternoon and began to set up four mist nets along the favoured “commuting” route preferred by many of the woodland bats in the area. With Andy’s local knowledge he was able to locate the best positions beneath the tree canopy where the bats’ flight could be funnelled into the waiting nets. Orly explained “we need to catch barbastelles to obtain a small blood sample which will be analysed and compared with other barbastelles”. The research is aiming to study the subtle genetic variation in relation to climate change. These small genetic fluctuations may be linked to potential physiological differences in the way bats regulate their body temperature and evaporative water loss, depending on which areas they live within their natural range between North Africa and Scandinavia.
As Orly set up her processing table on one of the few flat areas in the woods she said “I will take a small wing biopsy to provide a sample of DNA and a tiny sample of blood to extract RNA to look at what genes are being used. The blood sample will be taken using a pipette and will extract under 1% of the bat’s body weight. After that, we check the bat is healthy before releasing it again.”
With the help of the volunteers, Tom, Mike and Christine, the four mist nets were set up before the darkness began to creep through the woods and the last hint of pink sky faded. Turning on the bat detectors soon revealed a pipistrelle that was examining the net; dancing nimbly around it without getting caught. From the volunteers’ previous experience, ‘pips’ have been seen darting around the nets but as the night fully darkened and the oak tree silhouettes merged with the moonless sky, the first bat trapped happened to be a pipistrelle.
Everything appeared to be going well until the Dartmoor weather brought a badly timed shower of rain. At the crucial time when the bats were beginning to emerge, this sudden downpour would possibly drive them back to their roosts and, as the night went on and a few more showers came and went, the woodland bats seemed to be staying in. One daubenton’s bat was caught but Orly decided that the conditions weren’t ideal to find barbastelles it might be wise to draw the proceedings to a close. The waiting continued for a short while but the only sound was the constant flow of the Becka Brook. Yes, it was time to pack up and go home.
Later in the week Orly was back in the Bovey Valley and, this time, caught one male barbastelle. She was able to extract the samples she needed and let the bat return, unharmed to the woodland. She plans to come back to the Bovey next year and, as one of the few known UK colonies of this species, it will provide some important data to complete the genetic picture of the species across the continent.
Orly’s website explains more about the work of her team:
Other related information:
by Matt Parkins