Need help with a bat?

Follow our advice

or call us on 0345 1300 228

Natterer's bat trends for Great Britain

Myotis nattereri

Species factsheetDistribution and abundance

GB-level population trends for Natterer's bat from the Hibernation Survey and the Roost Counts are shown on this page.

Population trends are also produced for Natterer's bat at a country-level for England and Wales. Insufficient data are available to calculate trends for Scotland.

 


 Hibernation Survey

GB index of Natterer's bat population from Hibernation Surveys

Natterer's bat hibernation survey trend GB

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 2016 is shown as a dashed line to indicate that it is provisional.

The smoothed index is currently 66.4% above the 1999 base year value, equivalent to an average annual increase of 3%. The smoothed index is currently signficantly higher than the baseline year, however this is primarily the result of increases in the index value between 2004 and 2010 - since 2010 the smoothed trend has been relatively stable. Differences between trends for England and Wales are not significant.

From all years for which data are available (1990-2016), counts from 506 sites contribute to the overall trend analysis (sites surveyed in two or more years with Natterer's bat recorded in at least one year).

 


 Roost Counts 

GB index of Natterer's bat population from Roost Counts

Natterer's bat Roost Counts 2016

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 2016 is shown as a dashed line to indicate that it is provisional.

The smoothed index is currently 3.1% below the 2002 base year value, equivalent to an annual decrease of 0.2%. Between 2006-2013 the smoothed index declined gradually, however at no point did it differ significantly from the baseline year. Since 2013 the smoothed index has been increasing, however overall there has been no significant change in the smoothed index since the baseline year. There are no significant differences between trends for England, Scotland and Wales over the last six years, although the limited sample size means that spatial patterns are difficult to assess.

Data from 82 sites contribute to the overall trend analysis from 2000-2016. The baseline year used to calculate this trend has been set at 2002 as very few roosts of this species were counted in earlier years.

 


Summary of survey results

The trend from the Hibernation Survey shows a significant increase in the smoothed index since the baseline year, while the trend from the Roost Count shows no significant change. As Natterer's bat switch roosts frequently (see Robustness of Monitoring), the Hibernation Survey is believed to be a more accurate measure of population change for this species. There is therefore evidence that populations of Natterer's bat in Great Britain have increased since 1999, however this finding should be treated with caution until the effect of this species' roost switching behaviour on the Roost Count trend is better understood.

 


Distribution and abundance

Natterer's bat is locally common and widespread throughout the UK. It is also recorded in the Channel Islands.

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

Country

UK

England

Wales

Scotland

N.Ireland

Number

148,000

70,000

12,500

17,500

48,000

 Source

 

 Harris et al. 1995

 Harris et al. 1995

 Harris et al. 1995

 Russ 1999

 


References

Harris S., Morris, P., Wray, S. & Yalden, D. (1995) A review of British mammals: population estimates and conservation status of British mammals other than cetaceans. JNCC, Peterborough.

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


Return to:

Top of pageSpecies population trendsReport HomeContents page

 

 

Natterer's bat factsheet

 

Listen to how Natterer's bat sounds on a bat detector 

 

Current distribution of Natterer's bat in the UK

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

Natterer's bat distribution

 

 

You should follow us
Bookmark and Share
 
E-bulletin

Subscribe today to receive the latest on bats and BCT direct to your inbox.

Bat Helpline

0345 1300 228