The barbastelle bat is one of the UK’s more rare bats and there is a lot we don’t know about its life, its behaviour and its habitat needs. The good news is that the barbastelle has been found in the Bovey Valley and, under the Moor than meets the eye project, the Landscape Partnership has put together a plan to study this small flying mammal.
February 2015 On Saturday 28th February, around 25 people got together at the Woodland Centre in Yarner Wood to put this study in motion. The atmosphere of the day captured the anticipation you might expect from a group of enthusiastic nature lovers about to embark on a new adventure.
The day began with a presentation from Helen Miller of the Bat Conservation Trust. Her passion for bats, even the ugly ones, shone through as she explained the basic ecology of woodland bats and the special skills they possess. Bats are, of course, not blind but they need the accuracy of echolocation to catch prey in the dark. They are adaptable animals and use the environment to their best advantage, but each bat tends to demonstrate some specialist behaviour, reducing competition between species.
Some bats are woodland specialists. They roost in trees and forage within and around woody areas; the Barbastelle is one of these. They prefer oak woods and are known to roost in cracks in trunks, splits in branches and under peeling bark. Trees with decaying limbs and unpruned storm damage may look a bit untidy but they are an enormously valuable habitat for many mammals and invertebrates. The Barbastelle tends to live in colonies in Wales and across southern England; the north-western tip of their natural range which reaches across Europe and Asia. These colonies use the areas around the roost for feeding but also strike out on their own and follow individual foraging routes of 6-8 km each night before returning to roost. Occasionally, the Barbastelles will change their central roosting site so, before the project got fully underway, some initial work was needed to double check they were still active in the Bovey Valley.
Dr Ruth Angell gave a short talk on the recent work she had been doing around the reserve to check for Barbastelle activity. Over the last year, she had been using some remote ultrasound recorders in both Yarner Wood and the Bovey Valley Woods, finding that they were still living in the Bovey Valley as before. She noted that the roosting sites had not always remained the same and this could be for a number of reasons, maybe some of the older trees have fallen.
Simon Lee of Natural England gave us some background on the East Dartmoor National Nature reserve. We learned that Yarner Wood was, in fact, England’s first NNR back in 1952 and many of their wildlife records go back to that time. These are valuable records, and the Pied Flycatcher study is still going on today. Around the reserve there is a series of sensors which are recording temperature and humidity and this will eventually result in a map that will help the site managers to understand the best places for invertebrates to emerge, providing food for birds and bats. The study results available for birds will possibly help to support this Barbastelle tracking project too.
Later in the morning, Helen Parr from Devon Wildlife Trust explained how a new project was being developed to record information on another rare bat that lives in Devon, the Greater Horseshoe Bat. There are 11 maternity roosts around Devon and one of them is at Bovey Tracey. There’s every chance the Bovey Valley Barbastelles may come across the Greater Horseshoes on their night time travels. We were all interested to find out that one third of the UK’s Greater Horshoe Bats live in Devon!
The final spot of the morning was taken by Andy Carr from the University of Bristol. He’s working on a PhD entitled “Bats in Woodland”. A major part of his study is to find out where the Bovey Valley bats go each night; radio tracking techniques are going to be needed to collect the information. There’s a lot of work to be done and Andy is recruiting a team of volunteers to help. He’ll offer a series of training courses and an opportunity for them to take part in a once in a lifetime project. He explained the outline of what will happen over the coming summer. Most people were intrigued but wondering just how many nights without sleep would be needed to follow the bats from roost to foraging grounds and back. One of the essential requirements seems clear – bats will become a big part of the volunteers’ lives!
The afternoon was taken up by a walk in the high oak woodland surrounding the Woodland Centre. Dave Rickwood of the Woodland Trust led the walk, explaining why the character of the oak woods had developed in this way. Hundreds of years of human endeavour, coppicing the oak for charcoal to power local industry, has created this wildlife haven. Oak is a particularly robust timber and the standing deadwood, cracked limbs and decaying branches on the woodland floor will provide perfect roost sites for barbastelles for many years. We had the chance to inspect many of the dark recesses of the trees where bats could be roosting. Endoscopes provide a view into these cracks and crevices that we wouldn’t normally be privy to, but must be used with great care not to disturb any of the residents.
The training of Barbastelle tracking volunteers will begin in April and the surveys will be carried out all through the summer. The final mapping of all this data is going to be revealing and fascinating, but the questions is, what will be uncovered about the nocturnal activities in the Bovey Valley?
Words and images for the Barbastelle Tracking Diary are by Matt Parkins
The Bovey Valley barbastelle tracking project is managed by the Moor than meets the eye Landscape Partnership comprising Dartmoor National Park Authority, the Woodland Trust and Natural England.