by Sam Smith ~ Bat Ecologist

Early one spring morning four members of Cornwall Bat Group met at the ferry terminal on Penzance Harbour. Despite being a little sleepy there was much excitement and anticipation, we were about to embark on a trip to the Isles of Scilly in the hunt for elusive Nathusius pipistrelle.

The trip was to form part of the National Nathusius' Pipistrelle Project, the project was launched in 2014 by the Bat Conservation Trust to improve the understanding of the ecology and current status for Nathusius' pipistrelles.

Nathusius pipistrelle is best known for being a migratory bat with many research projects being undertaken in Europe, however, very little was known about its distribution status in the UK.  Cornwall Bat Group started to take part in the project in 2017 and as a member of the Isles of Scilly (IOS) Bat Group I was absolutely delighted to be invited over to the Islands to try to find this rare species.

Our first day set the pace well, the weather was glorious and the sea flat calm with Risso’s dolphins spotted on route.  On arrival the equipment was to be transferred to the wonderful Longstone Lodge while we enjoyed lunch in the sunshine with members of the IOS Bat Group and the Royal Society of Biology.  This was followed by a quick recce of potential bat sites before heading out for the evening.  Mike had very kindly supplied the location of bat detector records of Nathusius pipistrelle and along with studying aerial photos suitable sites had been identified but needed to be ground truthed.

Harp Trap in place at Higher MoorsOur first night we were based at Lower Moors so we could demonstrate the use of harp traps to the participants on the Bat Group walk.  The project is carried out under a Natural England license and this allows those named on the project licence to use special acoustic lures to attract bats into harp traps.  Once bats are caught the size, weight, age, sex and reproductive status of each bat is assessed before they are safely released.  Fate was on our side and when we checked the harp traps with the members of the bat walk we had our first bat, a Common pipistrelle!!  No Nathusius pipistrelle was caught on the first night but it didn’t dampen our spirits, we have some sight seeing planned for the next day!

After a super day on St Agnes we stocked up on supplies and headed out to Porth Hellick, I have travelled all over catching bats but this was one of my favourite locations, what a view for processing bats!

The traps were set up and while we prepared the processing area we watched as the many Swallows were finishing up the day shift.  There was a short break in activity before the night shift commenced, there were Common pipistrelles hunting over the water, vegetation and the strandline.  It wasn’t long before there were a number of Common pipistrelles to process and on the second check of the harp traps there was a noticeably larger bat.  Not wanting to get too excited we processed the bats in order until it was turn for the bigger one!

After taking every measurement that was needed, including measuring the fifth finger, everyone was absolutely over the moon to confirm it was indeed a Nathusius pipistrelle.  Such an achievement to confirm the species is present on the Island but at the same time asks lots more questions.  To make the evening even more special the Manx Shearwaters could be heard out to sea and we suspect possibly coming into land.

The last day was spent exploring St Mary’s before we headed back on the Scillonian that afternoon, we all had big smiles and were busy planning the next trip.

It is hoped that, with the use of bat detectors, more records will be confirmed this season to try to establish the distribution of this species on the Islands.  This can start to create an understanding of where they are, potentially identify roosts and maybe inform future trapping projects?

Huge thanks go to IOS Bat Group for inviting us and the very kind donation made. A massive thanks also go to the amazing volunteers Andrew, Rick and Marion. Without these guys I wouldn’t be able to run the project let alone combine holidays with catching Nathusius!

All photos and text provided by Sam Smith | Bat Ecologist