Background to the Mells Valley SAC Bat Landscape Survey

The Mells Valley Special Area of Conservation (Mells SAC) was designated in 1996, as extensive studies had shown an estimated 12% of the UK population of Greater Horseshoe bats were using the area. However since the year 2000 there have not been an further detailed studies to confirm the bats recent usage of the wider landscape.

This long term project will survey all the bats of the Mells SAC and its Ecological Zone of Influence (EZI) using many low cost static ultrasound recorders. The study area includes most of the active East Mendip stone quarries and their surroundings.

The project aims are:

  1. To quantify and benchmark the bats use of the whole area, to enable future long term monitoring of changes in the bats use of the landscape.
  2. To identify new bat “hotspots”, which may lead to discovery of new bat roosts, with particular interest in Greater (and Lesser) Horseshoe maternity roosts

The project is lead by volunteers from the Somerset Bat Group, and supported by Hanson UK.   It includes community events and stakeholder engagement.

The bat survey involves recording of bats echolocation using using many low cost static Audiomoth ultrasound recorders and analysis of recordings. This is similar to the process used in the Bat Conservations Trusts (BCT) British Bat Survey Pilot, but using experimental software on the Audiomoths so they record only when they detect ultrasound, such as bat echolocation.

It is envisaged to run the project for a minimum of two years, with options to extend, or revise focus of the project over the years.  The aim is for well over 1000 nights recordings each year.

More information in the project proposal document.

The proposed survey area is shown on the map below:

Mells SAC Bat Landscape survey with Key v0-5

Click here to download a hi-res version of this map.


A Somerset Bat Group project supported by Hanson UK hc_hanson