Wales Bat Conference & Workshop 2013 Abstracts

Transcription

1 Colin Morris, Vincent Wildlife Trust Castles in the Air Wales Bat Conference & Workshop 2013 Abstracts Despite a widespread distribution over the central southern counties of England, by 1990 records of Bechstein's bats (Myotis bechsteinii) in the 20 th century only numbered some 100 animals. The low number of records was due in part to their roosting ecology, typically using difficult to find hollows in trees during both summer and winter. In addition, advances in bat detector technology at this time was of little use in detecting this species as they have a very quiet echolocation call, which also couldn t be distinguished from other Myotis bats. When reports from Europe indicated that German researchers had successfully attracted colonies of breeding Bechstein s bat in the 'new' Schwegler woodcrete bat boxes, the Vincent Wildlife Trust saw an opportunity to trial them in the UK. In 1993 the Trust imported 50 2fn boxes and erected them in broadleaf woodland in southern England alongside 50 traditional wooden boxes. This comparative study was aimed at determining bat box selection preferences in this elusive, and any other bat species that might use the boxes. Maggie Andrews, Liverpool John Moores University Monitoring a P. pygmaeus roost for 20 years: what can we learn? Peter T. Andrews, Oliver Lodge Laboratory, The University of Liverpool, L69 3BX, UK. Robin G. Crump, Thrustle Mill Cottage, Freshwater East, Pembrokeshire, SA71 5LT, UK. David J. Harries, Somerton Cottage, Hundleton, Pembrokeshire, SA71 5RX, UK. Margaret M. Andrews, * Liverpool John Moores University, Liverpool, L3 3AF, UK. * m.m.andrews@livjm.ac.uk deceased Visual counts of Pipstrellus pygmaeus emerging from an established nursery roost have been recorded weekly for 20 years from April to September. The methods used and the benefits of long-term quantitative studies are discussed in relation to the need to monitor the activity of endangered insectivorous bats and the influence of weather in Spring, after the bats have emerged from hibernation. Henry Andrews, Andrews Ecology Ltd SHAPES A holistic approach to finding tree-roosts; just sit back, relax, and watch the pretty patterns John Haddow, Central Scotland Bat Group, and Auritus Wildlife Consultancy Looking for Leisler's" subtitle: How rare are these bats in Scotland? Leisler s bat Nyctalus leisleri was first recorded in Scotland in 1988 and since then a population of the species was known to exist in a small area of Dumfries-shire, mainly from

2 checks of bat boxes in forests. In 2009 the re-roofing of a school building where Leisler s bats were periodically recorded prompted the need for more knowledge of the Scottish population of the species. In 2010 a project aiming to find out more about the species involved catching and radiotracking four individuals in the Cree Valley and Glen Trool area, north of Newton Stewart. These four bats roosted in bat boxes or tree holes, and no evidence of a maternity/ nursery roost was found in the area. Better knowledge of the species and its echolocation calls, compared with noctule Nyctalus noctula, led to an examination of recordings from monitoring sites across Scotland. This revealed that most of the recorded Nyctalus type calls from the southwest of Scotland were Leisler s bat, while only noctule was recorded in the southeast. The likely breeding distribution of both species has been shown to extend north to a line between Glasgow and Edinburgh. In 2011 and 2012 the project focused on Culzean Country Park in South Ayrshire (managed by the National Trust for Scotland) and a nursery roost of around 40 females was found within the park. Females from the roost were followed by radiotelemetry in both years, as well as three males in total, and data was gathered on foraging areas and range in and around Culzean. A total of 14 trees have been identified so far to have been used for roosting, all within the country park and within a circle of 1km diameter. Tree species include oak, ash, beech, poplar and Scots pine, but the main nursery roosts have been in rot holes in mature Scots pine trees. To date this is still the only breeding location for the species recorded in Scotland. Dr Sandie Sowler, Ecological Consutlant The application of Percentage Confidence in the identification of big bats -,Noctule, Serotine and Leislers. You can never have 100% confidence in any sound identification (without a bat in the hand or DNA analysis). Other criteria are important to take into consideration. This presentation discusses the situations when >90% confidence can be applied to big bat sound files and how to work out confidence in sound files when big bats have been recorded in clutter, foraging or socialising. It also looks at the key criteria for these three species. Sam Dyer, Sam Dyer Ecology and Gwynedd Bat Group The North Wales Serotine Project In June 2010 a recording of a serotine bat was made in the village of Llanddulas on the North Wales coast. This, being so far out of the recognised distribution of the species, was of great interest and sparked the beginning of the North Wales Serotine Project, a collaboration between Clwyd, South Lancashire and Gwynedd Bat Groups.

3 The first phase of the project involved detector surveys in 2010 and 2011, leading to two radio tracking sessions in This project resulted in the location of the first known maternity roost for the species within the region. The radio tracking results have given some fascinating insights into the behaviour of this species at the study site, and also has given rise to the bigger question: What is the true distribution of serotines within North wales? Jean Matthews, Mammal Ecologist, Natural Resources Wales Discovering bats in Gwynedd two approaches to bat surveying Jean Matthews 1, Sarah Cartmel 2, Alison Johnston 3 & Geoff Billington 4 1 Gwynedd Bat Group & Natural Resources Wales, 2 Ecology Matters, 3 Alison Johnston Consultancy, 4 Greena Ecology We will describe the methods and results of two approaches to bat surveys in Gwynedd. A radio-tracking study that was undertaken in 2009 to identify foraging areas and additional roost sites used by lesser and greater horseshoe bats at a mine in the Conwy Valley. The site has been monitored by the Gwynedd Bat Group since the 1980s. At least 3 individual greater horseshoe bats have been recorded at this site the first in 2001 amongst the furthest north records for the species. Bat Camp has become an almost annual event when a group of Gwynedd Bat Group volunteers descend on a local estate with the aim of finding out more about the bats in the area, providing training in survey techniques and having a good time in the process. Alan Brown, Senior Remote Sensing Manager, Natural Resources Wales Remote monitoring It is possible to access for free, LANDSAT imagery for anywhere in the world. There are also two open-source software programs suitable for looking at satellite imagery and air photography. LANDSAT is now readily available and important because it has wide coverage, an unrivalled archive stretching back to the 1980s, a comprehensive set of spectral (colour) channels and excellent calibration. A new satellite in the same series has recently been launched, giving continuity over the next decade. QGIS was used to read in a stack of individual LANDSAT channels to form a false colour image. After a description of the channels in relation to the way vegetation reflects light, the image was then cropped, registered to the local projection, and the colours stretched and balanced to optimise the colour information shown on screen. A second programme, Imagej, was used to further enhance the colour information in a satellite image or air photograph, by decorrelating the three channels corresponding to red, green and blue on screen. This showed the potential information hidden in apparently uniform or low contrast air photographs. Marine examples were used to illustrate this. Finally, the concept of pan-sharpening was briefly introduced. This free software is available to everyone and can be used to look at freely available images, enabling anyone interested to start understanding the properties of satellite imagery. For example, the colours corresponding to features of interest, the spatial resolution and the potential to map objects by analysing not only shape and texture but

4 colour information. Though remote sensing analysis will need expert help, anyone can do a great deal towards understanding in a visual way the information content of imagery in its most familiar context: field observations.` Henry Andrews, Andrews Ecology Ltd Bat Tree Habitat Key Bat Tree Habitat Key is a new initial assessment tool designed to assist in the performance of predictive assessments of Potential Roost Features in trees. It was released for fieldtesting in December 2011 and is free to anyone who wishes to use it ( see the downloads tab). Following feedback already received they key will be integrated into an enlarged field-guide which will be free to download in December However, it is intended that the guide will be updated annually (and will remain a free web-hosted document) as more information becomes available, and to this end delegates are invited to participate in its ongoing refinement and provide feedback to Henry at henry.andrews@aecol.co.uk. Stephen Davison Monmouthshire Bat Group Barbastelle and Bechstein s do not exist in South East Wales? Bechstein's and Barbastelle bats were not known from Monmouthshire in spite of what looks like plenty of suitable habitat. This presentation looks at the design, modification and results to date of a project run by the Monmouthshire bat group to look for these elusive bats. Dr Jane Sedgeley, Vincent Wildlife Trust Our Beacon for Bats, Safeguarding lesser horseshoe bats in the upper Usk Valley A Project Update The Vincent Wildlife Trust s Our Beacon for Bats Project is a three- year project funded by the Brecon Beacons Trust, the Heritage Lottery Fund and Natural Resources Wales. The project is based in the upper Usk Valley, home to one of the most significant populations of lesser horseshoe bats in Europe. Working closely with partner organisations such as Brecon Beacons National Park Authority, Brecknock Wildlife Trust, and Brecknock Bat Group, we are promoting the presence of lesser horseshoe bats by providing learning opportunities for schools, local community groups and individuals. We are also working with local landowners to enhance habitats for lesser horseshoe bats to better link day roosts, night roosts and feeding areas. This presentation summarises our achievements in 2012 and describes our work for this year and for the future. In 2012, we were involved with 16 events (public talks, a training workshop, roost visits, surveys, agricultural shows and bat walks) visited seven schools, surveyed 20 km of canal

5 and used Anabat detectors to assess hedgerow use. A total of 673 volunteer hours were clocked up between May and September. So far in 2013, we have worked with farmers, contractors and an army of volunteers to plant 2,500 wet woodland trees and 6,800 hedgerow trees equating to approximately 2.9 km hedgerows and 2.07 ha of wet woodland. As part of a trial to enhance night roosting opportunities, we have installed three bespoke kit-set roosts and have adapted a garden shed and three WWII pillboxes. We have run a workshop specifically for planning and historic building professionals, two bat detector and survey training days for volunteers and a hedgerow and wildlife training day for highways staff is time-tabled for August. We are currently planning a legacy for the project. This will include a comprehensive GIS bat map of the area, to include key features such as day roosts, night roosts, foraging areas, commuting routes and important hedgerows. This map will be made available to the local records centre and planning authority. We will also be providing bat detectors for schools and a bat detector loan service.