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Common pipistrelle trends for Great Britain

Pipistrellus pipistrellus

Species factsheetDistribution and abundance

GB-level population trends for common pipistrelle from the Field Survey and the Roost Count are shown on this page.

Population trends are also produced for common pipistrelle at a country-level for England and Scotland. There are currently insufficient data to produce population trends for this species in Wales.


Field Survey

GB index of common pipistrelle population from Field Surveys

Common pipistrelle Field Survey GB 2015

Note: The graph above shows the unsmoothed index value for each year (green crosses), the smoothed trend (solid line) and 95% confidence intervals (dotted lines). The smoothed trend for 2015 is shown as a dashed line to indicate that it is provisional.

The smoothed index is currently 81.1% above the 1999 base year value, equivalent to an annual increase of 3.8%. The trend has increased consistently since monitoring began. There has been a significant increase in the smoothed index since the baseline year.

Data from 599 sites surveyed between 1998 and 2015 contribute to the overall trend.


Roost Count 

GB index of common pipistrelle population from Roost Counts

Common pipistrelle Roost Count GB 2015
Note: The trend for 2015 is shown as a dashed line to indicate that it is provisional. The figure shows trend analysis results (solid line) with 95% confidence limits (dotted lines).

The smoothed index is currently 51.6% below the 1999 base year value, equivalent to an annual decrease of 4.4%. The trend has declined since monitroing began. There has been a significant decline in the smoothed index since the baseline year. However this trend should be treated with caution as common pipistrelle regularly switch between different roosts, and there is evidence to suggest that this frequent roost switching can negatively bias population trends calculated from Roost Count data.

Data from 488 sites surveyed between 1997 and 2015 contribute to the trend (sites surveyed in two or more years).


Summary of survey results

The trend from the Field Survey shows a signifcant increase in the smoothed index since the baseline year, while the trend from the Roost Count shows a significant decline. Data from the Field Survey are considered to more reliably reflect changes in bat populations than data from the Roost Count, as there is evidence to suggest that for species which regularly switch roosts trends estimated from Roost Count data can be negatively biased. Therefore the population of common pipistrelle in Great Britain is considered to have increased since 1999.


Distribution and abundance

Common pipistrelle is widely distributed across the UK. 

Population estimate 

The population estimates are considered to be poor and should be treated with caution. Estimates are based on very limited population data and rely on expert opinion only.














 Battersby et al. 2005
(incl N. Ireland)




 Russ 1999



Battersby. J. (Ed) & Tracking Mammals Partnership. (2005) UK Mammals Species Status and Population Trends. First Report by the Tracking Mammals Partnership. JNCC/Tracking Mammals Partnership, Peterborough.

Russ, J.M. 1999. The Microchiroptera of Northern Ireland: community composition, habitat associations and ultrasound. Unpublished PhD thesis. Queen’s University, Belfast.


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Common pipistrelle factsheet


Listen to how common pipistrelle sounds on a bat detector 



Current distribution of common pipistrelle in the UK

(Map taken from 3rd Report under Article 17 on implementation of the Habitats Directive in the UK, JNCC 2013)

Common pipistrelle distribution 



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