Hibernation Survey

The NBMP Hibernation Survey is continuing again in winter 2023/24 in line with IUCN guidance on preventing human-to-bat transmission of SARS-CoV-2 (the virus that causes the disease COVID-19). A precautionary approach is essential until we have a better understanding of the risks to bats. We have put together a set of risk assessments (download here) to help surveyors assess the potential risks to bats and inform whether it is appropriate to survey each site this winter.

Click here for more information.

Many hibernation sites are surveyed regularly by individuals and bat groups throughout the UK. Through the NBMP we aim to collect and analyse counts on a UK-wide scale in order to produce annual species population trends. Local temperatures and the structure of the site can affect the number of bats using sites in winter. These factors need to be taken into consideration during any analysis so that conclusions can be made on bat population trends and not bat behaviour. We aim to identify changes in numbers of bats over and above ‘natural’ fluctuations, and highlight any signs of significant change.

Steps you need to take for the Hibernation Survey

Receive your survey pack in November

In order to take part in hibernation surveys you need to hold a bat licence that permits you to carry out hibernation surveys or know of a licensed surveyor who can accompany you. For further information about the relevant licence required, please contact your Statutory Nature Conservation Organisation (SNCO) headquarters or BCT (nbmp@bats.org.uk).

The pack includes survey forms and instructions to carry out this survey. The pack will be sent by email or by post depending on your preference. Please read these important health and safety documents below before you start your survey. Download an example risk assessment form for use at hibernation sites. Download BCT's safeguarding policy statement.

Carry out surveys from December-March

The standard survey method for the NBMP is to make one count in January and one count in February. We are now able to use counts from December to March in trend analysis so please do submit any counts you make, even if they are not within the January/February survey period. Try to ensure that there is at least one week between each count. If you cannot make a count between these dates, then you can choose the next closest date. Please mark it clearly on the count form. We are aware that at some sites counts are made outside the January/February period to ensure consistency with long-term monitoring at these sites.

Submit your counts

Once you have completed your surveys, submit your counts online or post your completed survey form to Freepost BAT CONSERVATION.

Your online recording pages enable you to view and download all data you have submitted. Read here how we share data via the NBN Atlas.

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