Barbastelles are a medium-sized bat measuring 45-58 mm long, with a wing span of 260-290 mm and a weight of 6-13g. Their fur is blackish on the back and the tips of the hairs may be pale cream or yellow, giving them a frosted appearance. They have a squat face, which gives them a distinctive, pug-like appearance.
The barbastelle bat is one of the UK's rarest mammals. Norfolk is one of the strongholds for this species, and has the only confirmed maternity roost within a building.
(Photo credit: John Kaczanow)
Action Plan Summary
- The barbastelle bat is mainly a woodland species. It uses old buildings and trees as summer roosts and underground sites and other suitable places such as hollow trees for hibernation. Riparian woodland may form an important habitat in some areas. It feeds mainly on lepidoptera taken in flight, but may also glean insects and spiders from vegetation.
- The barbastelle is widely distributed in England and Wales, with centres of population in south-west and mid-west England, and Norfolk. It is believed to be rare in the UK.
- In 1995, the UK barbastelle population was estimated to number 5,000-10,000 individuals (Harris et al., 1995). The overall population trend is not known, although this species has been targeted as part of the Bat Conservation Trust’s recent Woodland Bat Survey (trialled 2004-2006).
- Currently, there are 16 known breeding colonies in England and Wales (SITA, 2007), compared to 2001 when only five maternity colonies were known (Greenaway, 2001 cited University of Bristol, 2005).
- Barbastelles are listed on Appendix II of the Bonn Convention (and its Agreement on the Conservation of Bats in Europe, 1994), Appendix II of the Bern Convention (and its appropriate Recommendations), and Annexes II and IV of the EC Habitats and Species Directive. It is protected under Schedule 2 of the Conservation (Natural Habitats, etc.) Regulations, 1994 (Regulation 38) and Schedule 5 of the Wildlife and Countryside Act 1981. The 1996 IUCN Red List of Threatened Animals classifies this species as vulnerable.
- East Anglia is considered to support a population that is 'highly significant in the context of national distribution', and has been identified as one of the core areas for implementation of the species recovery programme (Harrington, Catto and Hutson, undated). The current known distribution of barbastelles is illustrated in Fig. 1.
- The Norfolk Biodiversity Information Service holds over 120 records dating back to 1857.
- Paston Great Barn (circa 16th century) is the only confirmed example in the UK of a barbastelle maternity roost within a building, and has been designated as a Special Area of Conservation (SAC). The Norfolk Barbastelle Study Group's work has put the significance of Paston Great Barn into its proper context, which is that it is part of a much wider population, albeit important in its own right for barbastelles and other species such as natterer's bat Myotis nattereri, brown long-eared bat Plecotus auritus and common pipistrelle Pipistrellus pipistrellus.
- Research undertaken by the Norfolk Barbastelle Study Group, and consultants' surveys, shows that barbastelles are sporadically distributed throughout most of Norfolk. Results of transects from the last two years show a strong population in north and west Norfolk.
- New records have been found during surveys undertaken as part of the environmental surveys for the proposed Northern Distributor Road. Further studies are being planned in 2009 to obtain a more detailed understanding.
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Current factors causing loss or decline in Norfolk
The threats to this species are poorly understood, but its low population density and slow population growth make it particularly vulnerable to factors such as:
- Loss and fragmentation of a broad mosaic of habitats including ancient semi-natural woodland, mature species-rich hedgerows, ancient trees and wood pasture, invertebrate rich pasture land and sympathetically managed riparian habitats;
- Loss, destruction and disturbance of roosts or potential roosts in buildings, trees and underground sites; and
- A reduction in numbers of insect prey as a result of habitat simplification, stemming from factors such as insecticide use and intensive grazing.
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Current Action in Norfolk
- The Norfolk Barbastelle Study Group has been working in North Norfolk since 2007, developing a standardised methodology to record barbastelle activity that can be repeated along defined transects over time. Surveys have also been undertaken in south Norfolk and north Suffolk.
- Mist net studies are being undertaken at Swanton Novers NNR (near Holt) in order to assist with the management of the wood (owned by Lord Hastings and managed by Natural England). It is hoped that this will be expanded in the future to concentrate on other sites throughout Norfolk.
- A special planning zone has been identified within a ten kilometre radius of Paston Barn (see Fig. 2), in which particular consideration will be given to the ecological requirements of barbastelles when considering planning applications.
- Paston Great Barns is being actively managed for barbastelle bats and restoration techniques are being developed as a blueprint for similar restoration schemes involving barbastelle bats elsewhere.
- The barbastelle colony at Paston Great Barn has been actively monitored since 1998 to assess colony performance and determine effects of external influences on barbastelle survival and behavior.
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Action Plan Objectives and Targets
- Maintain the current range of B. barbastellus in the UK at 68 occupied 10 km squares.
- Maintain the current range of B. barbastellus in Norfolk at 31 occupied 10 km squares (see Fig. 1)
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- 10km squares with records, but no roosts recorded. Roosts recorded within 18 km squares (Richardson, 2000)
- Please note that this figure will be revised following the completion of the Norfolk Bat Roadside Survey which is due to be undertaken 2009/2010. The feasibility of developing additional targets related to density will also be assessed at that time.