Need help with a bat?

Follow our advice

or call us on 0845 1300 228

Lesser horseshoe bat population trends

The results of the population trends for lesser horseshoe bat from the Hibernation Survey and the Roost Counts are shown on this page, and interpretation of survey results.

Click here for details on how the population trends are calculated.


Hibernation Survey

UK Index of lesser horseshoe bats from Hibernation Surveys (1997-2012).

Note: The trend for 2012 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).

Lesser horseshoe bat Hibernation Survey 2012

The 2012 index is lower than in 2012, but overall the index is currently 77.2% above the 1999 base year value, equivalent to an annual increase of 4.5%. The upward trend is significant.

From all years for which data are available (1990-2012), counts from 256 sites contribute to the overall trend analysis.

There is no statistically significant difference between English and Welsh trends.

Number of Hibernation Survey sites

Period Total no. sites No. sites with bats

2012

416 133

1997-2012

983 313

Roost Counts

UK Index of lesser horseshoe bat roost size from Roost Counts (1997-2012)

Note: The trend for 2012 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).

Lesser horseshoe bat Roost Count 2012

The index is currently 67% above the 1999 base year value, equivalent to an annual increase of 4.0% and the upward trend is significant. Data from 242 sites contribute to the overall trend analysis.

England: average annual rate of increase is 4.6%

Wales: average annual rate of increase is 4.0%

There is no statistically significant difference in the rates of increase between England and Wales.

Number of Roost Count sites

Period No. sites UK No. sites England No. sites Wales Roost size
2012 180 (178 with bats present)  73 107 Average 135
1997-2012 297 (293 with bats present)  122 175 Average 116  

Interpretation of survey results

The significant upward trend from both surveys indicates that the population has increased since the start of the monitoring programme. The increase in lesser horseshoe bats is likely to have resulted from a succession of mild winters over this period enhancing winter survival, and direct positive conservation action. The increase is seen in both England and Wales.

Return to Species population trends

Return to Contents page

 

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

0845 1300 228