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Nathusius' pipistrelle survey

Click here for the current National Nathusius' Pipistrelle Project

The page below relates to BCT's previous Nathusius' Pipistrelle Survey, which ended in 2014.


Nathusius' pipistrelle is considered rare in the UK but may simply be under-recorded. It is often found at large waterbodies, particularly during its autumn migration period.

This is the first systematic UK-wide survey for this species. It is currently on hold while we explore new sources of funding for its continuation.

The video clip below shows a Nathusius' pipistrelle foraging over a lake.


You will need a broadband detector (frequency division/time expansion/Anabat/full spectrum sampling) and a recording device. Equipment for this survey is available to borrow from BCT. Nathusius' pipistrelle presence is verified through sonogram analysis. You can analyse your own recordings or send them to BCT staff for analysis.

A summary of results from the first six years of the survey is available here.

A guide to taking part

This survey is currently on hold but we hope to start it up again in the future.

August - we send you your survey pack

This includes survey forms, full instructions and a survey route map if you are surveying a repeat site.

You will be allocated one or more lakes to survey. If the survey is at a new location you will need to map out a route.

Nathusius' pipistrelle survey route map 

August/early September - visit your site during the day

Seek landowner permission if needed.

Walk the route to check it is safe and accessible. If needed, modify the route to avoid potential hazards when walking at night, or contact us for a different site.

Field Survey daytime recce

September - visit your site on two evenings to carry out surveys

The first survey should be between 1st and 15th September and the second survey between 16th and 30th September.

The survey begins 20 minutes after sunset and usually takes about one hour.

You should not survey alone, so you will need one or more survey buddies. Bring friends or family along for safety and to share the excitement of watching bats!

Nathusius' pipistrelle survey

Connect your bat detector to your audio device (if you are not using a detector with built-in recording). Click here for tips on avoiding some common problems with recording from a bat detector.

Make a continuous audio recording while walking between each of your ten stopping points and while standing for four minutes at each stopping point. You should end up with 20 audio tracks from your 10 walks and 10 stops.

Lake survey

If listening in heterodyne mode tune the detector to 40kHz and log on your field form at which walks and spots you think you hear Nathusius' pipistrelle. Also log where you hear other pipistrelle species.

Send us your results

Once you have completed you surveys, post us your completed forms and recordings.

Nathusius' pipistrelle survey form

Your survey pack will contain full instructions for carrying out the survey method and identifying the species.


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Bat Helpline

0345 1300 228