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Summary

 

  • This report covers the period 1997 – 2007 of the NBMP. The primary aim of the programme is to produce statistically-defensible population trend data for all resident UK bat species.
  • Effective bat conservation relies on gathering information to identify changes in populations that are of conservation concern.
  • The main monitoring techniques employed by the programme are the Field, Waterway, and Hibernation Surveys and summer maternity Colony Counts.
  • Newer monitoring techniques involve the use of broadband bat detectors to record a range of species along roadsides and woodland transects.
  • Volunteer surveyors collect data and are supported by the monitoring programme through training workshops and the office team.
  • In 2007 970 volunteers took part. This is a slight increase of 0.3% compared to the number taking part in 2006.
  • The total site network now stands at 4,119. In 2007 a total of 1,839 sites were monitored of which 76.4% were repeat sites. There has been a 2.5% decrease in the total number of sites monitored compared with 2006.
  • At present sufficient data are collected to produce population trends for 11 of the UK’s 17 resident bat species.
  • Significant positive trends were reported for greater horseshoe (Colony Count), lesser horseshoe (Hibernation Survey & Colony Count), Natterer‟s bat (Hibernation Survey), common pipistrelle (Field Survey), and, for the first time, brown long-eared (Colony Count).
  • The greater horseshoe and brown long-eared Colony Count trends should be treated with caution.
  • Daubenton‟s bat is showing an increase in the Hibernation Survey and Waterway Survey but these trends are no longer quite significant.
  • Significant negative trends were reported for common pipistrelle and soprano pipistrelle (Colony Counts) though these may simply reflect the mobility of these species. Field surveys for each of these species are presently considered more robust.
  • Surveys for other species showed no significant changes.
  • Data have contributed to major UK reporting obligations. NBMP staff have participated in UK and European knowledge-sharing workshops.
  • In May 2008 NBMP data enabled bats to be added to DEFRA‟s set of „indicator species' which help measure progress towards the Government's target of halting biodiversity loss by 2010.
 
 
 
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