Noctule trends for Great Britain
GB-level population trends for noctule from the Field Survey are shown on this page.
Population trends are also produced for noctule at a country-level for England. There are insufficient data to calculate a population trend for this species in Wales. This species is only rarely recorded in Scotland, therefore there are insufficient data to calculate a trend for this country.
GB index of noctule population from Field Surveys
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 16.3% above the 1999 base year value, equivalent to an annual increase of 1.0%. The trend has fluctuated since the start of monitoring. It rose to a peak in 2008 and then deckined, although the rate of this decline has slowed in recent years. Overall there has been no significant change in the smoothed index since the baseline year.
Data from 600 sites surveyed between 1998 and 2015 contribute to the overall trend.
Summary of survey results
The trend from the Field Survey shows no significant change in the smoothed index since the baseline year. The population of noctule in Great Britain is considered to have been stable over the period 1999-2015.
Noctule is a relatively widespread species in England and Wales, and it is found into southern Scotland, but it is uncommon. It is absent from Ireland.
The population estimates are considered to be poor and should be treated with caution. Estimates are based on limited population data and are extrapolated from surveys of only part of the population
|Number||50,000||45,000||4,750||250||does not occur|
|Source||Harris et al. 1995||Harris et al. 1995||Harris et al. 1995||Harris et al. 1995|
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.