BSG Ecology has started work on a range of new research projects in 2014. This article summarises progress to date on new bat research.
Bat Detectors on North Sea Ferries
Matt Hobbs and Gareth Lang have deployed bat detectors on two ferry routes that cross the southern North Sea this spring. The first was deployed on 12 April on the Pride of York, a P&O vessel that runs between Hull (East Yorkshire) and Zeebrugge (Belgium); with a second deployed on 1 May on Flandria Seaways, a DFDS freight route that runs between Felixstowe (Suffolk) and Vlaardingen (Netherlands). The key aims of the study are to see whether bats are recorded in offshore areas to provide more direct evidence of bat migration than using fixed onshore locations. Regular detection of bats over central areas of the North Sea in spring and autumn would provide a clearer indication that migration was occurring. The study is being supported by MARINELife (who run cetacean and seabird surveys from both vessels), the Chief Officers onboard each vessel (who are downloading the detectors and returning the data to us), and by Envisage Wildcare , a wildlife equipment supplier, who have generously provided all of the survey equipment.
During the past few years BSG has deployed bat detectors at a number of coastal locations on the east, south and west coasts of England in order to look for any patterns of occurrence of bats that could indicate migratory movements between the UK and continental Europe. A particular focus has been the southern North Sea coast and the results have been very interesting, with encounter rates of Nathusius’ pipistrelle increasing in spring and autumn, when this species is known to be migrating in continental Europe (some of our recent work can be found here ). The ferry study is a logical next step to try and record direct evidence of migration at sea.
It remains to be seen whether there will be problems collecting data on the ferries, as the conditions at times will be extremely inhospitable and there may be no strong reason for bats to fly close to ferries when migrating. The results are starting to come in, however, and we will report back in winter 2014/15 on our findings. We have already recorded single Nathusius’ pipistrelle from each ferry in May and are look forward to what the summer and autumn may bring.
Bats on the Pembrokeshire Islands
Rachel Taylor and Matt Hobbs are leading a project looking at seasonal variation in bat encounter rates and species diversity on the islands of Skomer, Skokholm and Ramsey. The islands are all situated off the west Pembrokeshire coast: Skokholm is the most southerly and the smallest of the three, being less than 2km in length; Skomer is approximately 3km north of Skokholm and is approximately 3km in length; Ramsey is in excess of 12km north of Skomer, and is also approximately 3km long. The islands lie between approximately 900m and 2.6km from the nearest mainland, with Skokholm being the most remote. Ramsay is run by the RSPB and the other two islands by The Wildlife Trust of South and West Wales.
In 2014 single bat detectors have been deployed on each of the islands. These are being maintained by the wardens on each island, who are downloading and sending it to BSG for analysis. They will remain on the islands until the end of October 2014. The work complements studies such as that being undertaken on Skokholm, where the wardens are keen to understand whether bats are using coastal sea caves (horseshoe bats do this along parts of the coast of mainland Pembrokeshire).
Our interest is focussed on whether there is evidence of seasonal change in the bat species on the islands. It will be of particular interest to note any apparent increase in the frequency of records of Leisler’s bat, as this species is widespread in Ireland, or of Nathusius’ pipistrelle, a species which our recent studies on the east coast have strongly suggested makes seasonal movements into and out of the UK; and for which there are also at least two known breeding colonies in northern Ireland. The data will also be of interest in that there is little baseline information about the bat fauna of these Welsh islands, so it will be good to help fill a gap in our current knowledge.
Stable Isotope Analysis of Nathusius’ Pipistrelle fur samples
In late 2013 we sent a large number of Nathusius’ pipistrelle fur clippings collected under license in the UK to the Institute for Zoo and Wildlife Research in Berlin for stable isotope analysis. The work has now been done, and we are in liaison with the researchers who have completed it to start interpreting the results.
We hope to update and issue a final report that brings together the result of all of the coastal bat research we undertook in 2013 over the next few months. This will include the results from the stable isotope analysis work.
BSG is also supporting research projects on Dartford warbler in South Wales; the use of artificial tunnels by great crested newts; and continues to work with Buglife with regard to monitoring the success of restoration and habitat creation initiatives on brownfield land. Summaries of these projects will appear on our website soon.
Top picture shows Greg Morgan, a RSPB warden at Ramsey Island, with an Anabat that will be deployed on the island until the end of October.