In 2014 we deployed bat detectors on two commercial ferries sailing routes through the southern North Sea. The two vessels were Flandria Seaways (DFDS Seaways) and the Pride of York (P&O Ferries), which sail from Felixstowe (UK) to Vlaardingen (Netherlands) and from Hull (UK) to Zeebrugge (Belgium) respectively. The aim of the study was to investigate the occurrence of bats over the North Sea, and to see if there were any clear patterns to records indicative of migration.
This study recorded Nathusius’ pipistrelle over the southern North Sea during both spring and autumn. Most of the records were considerable distances from shore. Other species recorded at sea, but close to land, were soprano pipistrelle and Leisler’s bat.
The timing of some of the Nathusius’ pipistrelle records, i.e. very close to dawn, indicated they may have been drawn to the ferries to roost. Most of the records were during periods of light, following winds, with three autumn records during a prolonged period of high pressure with an established airflow from the north and east. Arrivals of continental birds were noted almost daily during this period along the coastline of the southern North Sea.
We believe the study is the first that has been published that provides evidence of bat migration recorded from offshore ferries in UK waters.
If you would like more information about this study, please contact Owain Gabb.
Top photograph courtesy of P&O Ferries- Pride of York