Survey Results 2017

The Devon Bat Survey results 2017 are in!

Thanks to all those who borrowed a detector in 2017, we recorded greater horseshoe bats at 230 sites out of the 705 surveyed. In total the survey recorded over 750,000 sound files. These fantastic survey results will help the bat project to plan further research. They are also invaluable in  providing targeted land management advice to landowners.

Survey Areas 2017

Survey squares 2017

The map above shows the location of the 705 survey areas using tetrads. A tetrad is a 2km by 2km grid square used for biological recording. Although people selected a 1km grid square to deploy their detector, a tetrad square is depicted to make it easier to view on the screen.

Greater Horseshoe Bat heat Map 2017

GHb Heat Map 2017

This second map shows the greater horseshoe bat ‘hotspots’  identified by the survey results of 2017. The strongest colours show where there were over fifty greater horseshoe passes in one location. This is only based on the sites surveyed. Just because an area of the map is absent of greater horseshoes it does not mean that they are not present here.

As the survey progresses we hope to compile a set of cumulative maps for all years.

Whilst we have some great technological aids for helping us to work out which are bats (and which are birds, crickets and general noise), we still need to manually check lots of the files. As you can imagine, it takes a huge amount of time to process the survey results.

Later in the spring, we will produce a further map showing the number of species recorded in each tetrad, so watch this space!

To take part in next year’s survey keep an eye on the Devon Bat Survey page – bookings will open during March 2018.

Useful links;

To see the 2016 results click here

For an overview of what’s involved have a look at the volunteer instructions

Devon Greater Horseshoe Bat Project