The Bat Conservation Trust runs an annual Bat Conference in September each year which is attended by bat groups, enthusiasts and professionals from around the country. They also hold regional conferences once every two years and this year’s Midlands conference was at the end of April. The focus of the conference is not exclusively based in the region, but has talks from local bat group members and researchers as well as spotlight talks from the various bat groups in a region so that neighbouring groups can find out about projects which others in the area are involved in.
The Warwickshire Barbastelle Project
Lois Browne gave an inspiring talk on the Warwickshire Barbastelle Project which has been running in Warwickshire for the last two years. This project studied the behaviour and habits of one of the rarest bat species in the UK through trapping and radio-tracking as well as traditional acoustic survey techniques. The study colony roosts in an ancient woodland site but forages further afield, leaving the woods and foraging in a valley to the south as well as around lakes and woodland fragments within 5km of the roost. Non-breeding bats were found to travel further to feed; up to 7km from the roost. Some bats were found to have very traditional routes which they stuck to each evening when they left the wood to reach their foraging grounds. Boxes erected as part of the project were used by the barbastelles, including use by maternity colonies. They found the Colin Morris design to be used preferentially. The project also carried out targeted work to enhance the local habitat for barbastelles, informed by the findings of their study. So far they have planted 800m of hedgerows and standards to improve connectivity, are developing three new wildflower meadows and have built a new pond.
Emergence behaviour of Natterer’s and brown long-eared bats
Rachel Fryer gave a talk on the emergence behaviour of Natterer’s and brown long-eared bats. She observed two known maternity roosts once a week between May and September and recorded each emerging bat to identify the earliest emergence time, the median emergence time and the number of bats emerging, and correlated this with environmental variables. The earliest emergence times proved interesting with records earlier than the textbook examples. The median emergence time for Natterer’s was 60-64 minutes after sunset whilst brown long-eared bats left a little earlier with a median emergence time of 44-49 minutes after sunset. The number of bats emerging were found to fluctuate between nights – this could relate to some bats remaining in the roost or the colony being split between different roost sites. However, there was a correlation between the number of brown long-eared bats emerging and the average wind speed with fewer bats emerging on windier nights. The light levels also seem to influence emergence behaviour with brown long-eared bats emerging later under higher light levels; and Natterer’s bats emerging earlier when there was higher cloud cover. This empirical information on the emergence characteristics is valuable as existing published information is often sparse and often doesn’t specify whether the time relates to the earliest or the median emergence time.
Species Distribution Modelling for Bechstein’s Bats
A talk given on behalf of Lia Gilmour from the University of Bristol shared the results of Species Distribution Modelling of Bechstein’s bats and the use of the results to identify further suitable habitat for this rare species. The principle behind this modelling is to look at the conditions in which the bats are found and identify further locations where these conditions are present. In theory therefore, if the SDM is modelling correctly, the bats may be found in these locations. This model found four key variables which appeared to be important: the presence of broadleaf/mixed woodland, a relatively low summer rainfall, a minimum January temperature of >7 degrees and a relatively high temperature range. This corresponds well with the southern distribution of this woodland dwelling bat. The model appeared to work well as new records were found to fall within the optimal or marginal suitability distributions predicted by the model. This is a valuable tool in targeting the search for further Bechstein’s colonies to those locations where the bats are most likely to be found. It will however only identify further habitat like the ones in the bats are known to dwell and so new colonies may still be found in unexpected locations outside of the current or accepted range. This problem is further exacerbated for the Bechstein’s as so much of the distribution is known from targeted surveys using acoustic lures to capture and identify the bats. These surveys were largely carried out in locations where the bats were most likely to be found – specifically broadleaf woodland sites in the south of the country and this will have influenced, in turn, the predictions of the models. It is a case of don’t look; don’t find and the risk with this approach is that more borderline sites may be overlooked if the limitations of the methodology are not appreciated.
Alcathoe Bat in the UK
Phil Brown has been undertaking research using DNA analysis of small myotis species bats. A cryptic species was recently identified in 2010 called the Alcathoe bat which is very similar to Brandt’s and Whiskered bats and, whilst known on the continent since 2001, was not known to exist in England. One of the aims of Phil’s research was to see whether these bats could be identified outside of their current known range of Sussex, Surrey and North Yorkshire. 70 sites were surveyed and 395 bats were caught of which 39 were whiskered/Brandt’s/Alcathoe (WAB). This targeted capture and DNA collection was supplemented by samples sent in by other bat workers around the country with the result that a total of 110 WAB samples were tested. 95 of these were found to be whiskered bats; 10 were found to be Brandt’s bats; and 5 were found to be Alcathoe. Sadly, these five bats were all found in Sussex/Surrey and so there remain no records in between their current known locations towards the north and south of the country.
Brumbats Flight Cage
Morgan Bowers from Brumbats gave an inspirational and enlightening talk on the new flight cage they have had built. This allows the bat carers to assess the health and abilities of rescued bats, gives the bats opportunity to exercise and to behave in a more natural manner, and allows them to be rehabilitated and soft-released with a more supportive environment if they take a little longer to build their abilities. This also saves the perennial bat carer issue of bats getting loose in the house and hiding in the most unlikely places – including inside a hoover! The flight cage is a good training tool as well as it offers a safe environment for new bat carers to learn their rehabilitation and handling skills. You can find out more about the flight cage here with some videos to watch too! Another blog on the conference can be found on the Brumbats page here.
White Nose Syndrome in the UK
The last talk of the day was given by Alex Barlow on White Nose Syndrome in the UK. This is a devastating disease in the USA which has seen mortality rates in hibernation sites of 97% for the little brown bat and 49% for the big brown bat. The syndrome is caused by a fungus which infects the bats and gives a characteristic white nose where the mycelium grows. The presence of the fungus leads to increased evapotranspiration and loss of electrolytes which effectively dehydrates the bat and it rouses out of torpor to drink – some bats have even been observed trying to eat snow. The survival of a bat through the winter is a finely balanced process and this wakening uses a large amount of the winter reserves of the bats which then can not find food to replace the energy they have lost. There were serious fears that this disease may spread to other locations but surveys and sampling across Europe have found the fungus but have not recorded any associated mass mortality events. DNA analysis of the fungus has found significant genetic diversity in Europe which suggests that it is endemic to the continent, whilst those in the USA are all genetically similar, suggesting it is a recent introduction. This may mean that the European bats have co-evolved alongside the fungus and will therefore be able to cope with it, whilst it is a novel pathogen to bats in the US and they have suffered badly from its effects. Further active surveys for the fungus are taking place through 2013/14 with 25 sites selected across the UK, especially those used for tourism or caving. The current state of knowledge allows us to be cautiously optimistic that this fungus should not lead to the same level of devastation in the UK as has been seen in the US.
Spotlight Talks on Local Bat Groups
The spotlight talks from the local bat ground included Lincolnshire all the way across to Warwickshire, Worcestershire and Derbyshire taking in Leicester and Rutland, Nottinghamshire and Birmingham and the Black Country on the way. A range of projects are underway including NBMP monitoring of roosts; the Nathusius pipistrelle project for which Nottinghamshire and Derbyshire are amongst the pilot groups; the BrumBats Batlas project which aims to extend their knowledge of bat distribution across the area; and a range of public engagement events including bat walks and talks. For more information on the activities of all of these groups, check their pages which are all linked above. Whatever your level of interest, there will be something to get involved with wherever in the Midlands you are!