Nathusius' pipistrelle survey

Nathusius pipistrelle In September 2009 we piloted a new survey at lakes/lochs, focusing on Nathusius' pipistrelle. A summary of results from the pilot survey is available here. We will be repeating this survey in September 2010.

Nathusius' pipistrelle is widespread across the UK but considered nationally rare, though it may simply be under-recorded. This species is migratory and the biggest influx of bats appears to be in September which is the peak month for in-the-hand and bat detector records. The UK also has a summer breeding population of Nathusius' pipistrelles, though only a handful of maternity roosts are known.

The key aim of this survey is to improve our knowledge of the autumn distribution of Nathusius' pipistrelle across the UK. In future we would also aim to gather sufficient data to look for evidence of changes in the levels of activity being recorded of this species across the UK. The survey uses broadband detectors which will also enable us to collect and examine data on other species at lakes/lochs.

Site allocation

When you sign up we will allocate you a lake/loch that is at least 1km in perimeter and close to your address (ideally within 5km of you but not more than 10km). If you have taken part before we will ask you to revisit the site you have previously surveyed unless you state that you would prefer a new site.

Survey method

The survey involves two visits to each lake/loch, one between 1st - 15th September and the second between 16th - 30th September. In advance you will need to visit the lake/loch during the day in order to map out a 1km route around the edge of the lake/loch and mark out ten evenly spaced stopping points on your map. If surveying a repeat site we will send you the route map and spot descriptions from the previous year so that you can follow the same route as before. On the surveys bats are recorded while walking between stopping points and for four minutes at each stopping point. The surveys begin 20 minutes after sunset and should take roughly one hour to complete.

Equipment needed

Ideally you will need a frequency division bat detector (see our bat detectors page for more details) and a digital recorder or mini disc recorder plus an audio connecting lead and headphones. This will enable you to follow the standard survey protocol which will involve making continuous recordings as you walk your route. These recordings will be analysed in order to verify any suspected Nathusius' pipistrelle records. If you have access to sound analysis software and would like to analyse your own recordings then please let us know and we will supply you with the sound analysis protocol for this survey.

If you wish to use an Anabat detector then please let us know and we will send you an Anabat survey form and protocol for this survey.

If you only have access to a heterodyne (tuneable) detector then you can still take part, as the survey protocol also includes instructions for identifying Nathusius' pipistrelle in the field using this type of detector. However, it will not be possible to verify any uncertain records. Sites with “Nathusius’ pipistrelle” or “Unsure Nathusius’ pipistrelle” heterodyne records will be a priority for revisiting with recording equipment in order to try and verify this species’ presence.

For the 2010 survey we will have some frequency division detectors and recording devices available for loan to volunteers taking part in this survey.

How to take part

You will need to indicate what equipment you plan to use so we can ensure we send you the most useful instructions. If you have any questions, please contact us at nbmp@bats.org.uk or on 020 7501 3628.