The extent of bat migration between continental Europe and the United Kingdom (UK) is poorly understood. BSG Ecology has been conducting studies looking at whether there is evidence of bat migration into and out of the country since early 2012. Using static detectors at various coastal locations and on North Sea ferries, we have consistently recorded peak levels of Nathusius’ pipistrelle Pipistrellus nathusii (a migratory species of bat) activity during the migration season for the species on the continent.
In 2013, our study was extended to include the analysis of stable hydrogen isotope ratios (d2H) of hair samples taken from Nathusius’ pipistrelle bats found in the UK. Samples were taken (under licence) from 25 Nathusius’ pipistrelles. These included dead and grounded animals, bats deliberately trapped as part of other studies and individual bats found during bat box checks at known colonies.
The results indicate that at least 40% of the sample had moved a substantial distance since they had moulted the previous summer. The data strongly suggest that a proportion of the bats sampled were migratory and that, given the predominant migration direction of this species in Europe (south-west to north-east) and their known distribution in the UK, these individuals originated from areas of northern or eastern Europe outside of the UK. The sample also indicates that some of the bats sampled are resident in the UK.
To view our report that provides full details of the stable isotope research, please click on the embedded pdf below. For further information on our bat migration studies please contact Laura Grant in our Oxford office on 01865 883833 or James Gillespie in our Newport office on 01633 509000.