How to take part in a Group Big Bat Count

Signing up

You can take part with your community group, or book onto a public Big Bat Count.

You will need to be in a team of between 2 and 6 adults with people you know, three adults per team is ideal. Children over 5 are welcome if each is accompanied by an adult.

On this page are sections for:

  1. Before the Big Bat Count – The things you need to do before the night.
  2. On the night preparation – What will happen on arrival at the Big Bat Count?
  3. Taking part in the Big Bat Count – This will all be covered on the night in the briefing, but it helps if you can read this before the night to familiarise yourself and your team with the process.
  4. The Close of the Count night.
  5. After the Count.

1/ Before the Big bat count night

To prepare for your Big Bat Count we ask that you do the following before the count night:

  1. At least one adult (hopefully more) from each team should install the iNaturalist app (not Seek) from the Google or Apple App store.
    • On Android the app is called “iNaturalist”
    • On iOS (Apple) it is “iNaturalist Classic” .
  2. Open the iNaturalist app and create an iNaturalist account.
  3. Your local Count organiser may ask you to join a local iNaturalist project.
  4. If you would like use our Ultrasound Microphones attached to your own phone to detect bats. Then also download another app. to your phone:
  5. It helps with both pre-event communications, and on the night, if the count leader signs everyone up to a WhatsApp, Facebook or email group for the night’s count.

2/ On the night preparation

On the night of the count, the teams of people meet at a central location to collect two bat detectors per team:

  1. The first detector is an ultrasonic microphone (Echo Meter Touch2 – EMT) attached to a tablet that can record and most importantly automatically identify the bat echolocation calls it hears.
  2. The second detector (Magenta) is non-essential and a “nice to have”, and given out to teams of 3 or more. It can be set to the frequency shown on the tablet and allows participants or more to listen to the echolocation calls the bat is making in real-time

Each team is then given instructions and a area or map showing an area that they can cover. This can be arranged in advance and could be on the team’s local streets, or open space.

During the preparation, the bat group leader will make sure that all teams:

  • Are aware of their area and the survey process to follow.
  • Have the required kit and know how to use it.
  • Have a copy of the “species lookup for the 15 species of Somerset Bats” laminate.
  • Have received the safety briefing, and have at least one hi-vis “BAT survey” vest per team.
  • Are aware all sounds will be recorded, and avoid creating sounds themselves as much as possible. Keys rattling, small change, rustling cagoules, zips .. etc are all common ultrasound sources.

3/ Taking part in the Big Bat Count

All the information below will be covered by the Bat Group leader, in the briefing before the event. However, you may want to familiarise yourself with the process in advance by reading below.

The aim is for each team to start the Big Bat Count of their soon after area at Sunset, and then survey for the next hour.

The process each team should follow is:

At the start of the Count

1/ Switch on the tablet by holding the power button on the side for 5 secs, it is marked in black on the case. Wait until you see the Big Bat Count opening screen with instructions on, then swipe up within 10 seconds. Click OK to any randon messages that may appear:

  1. Ensure the EMT microphone is securely plugged in..
  2. Start the Echo Meter app on the tablet, using the icon in the middle of the screen.
  3. Press the big green round Start button.
  4. At the bottom of the screen are 5 buttons, these need to be configured as follows:
    • Start recording using the round light grey button with a light red square 2nd from left. (bat autoID only works when recording).
      • When recording the button turns dark grey with a red square, and a flashing red/green dot and timer appears next the words “LIVE MODE” at the top of the screen.
      • The grey button 2nd right, with three vertical lines should be dark grey, not light grey (expanded display, always scrolling, impossible to use)
  5. The EMT microphone, this is directional so ensure it is always pointing upwards, or towards any bats
  6. Start recording at the start time of the count, and leave it recording the whole duration of the count. Only click Stop (the 5th button at the bottom) at the end time of the count.
  7. It is possible to “scroll back time” to look at past recordings. However then the tablet stops showing current bat calls. Click the tiny “Return to real-time” link in white text in the upper right corner of the screen to correct this.
  8. If at any time the Echo Meter app freezes during the night, the quickest way to reset is to restart the tablet. Hold down the side power button and hit the “restart” button onscreen twice. Then follow steps 1-5 above again.

2/ Switch on the Magenta bat detector, and set it initially to 45kHz

3/ Log into iNaturalist on the internet-enabled phone.

How to carry out the Big Bat Count

  • Aim to cover as much of your area as you can in the next hour after sunset
  • Always stay in public places, footpaths, parks etc. Never enter private land, even to follow a bat.
  • Ultrasound (sounds beyond our hearing) is very common. From cars, to birds and crickets, ultrasound is everywhere. Hence the EMT device will be recording most of the time, and will often come up with no bat detected, or “No ID”
  • Keep moving around your area until a bat is seen or heard, in real life, or via the detectors. These will usually be rhythmic patterns of sound.
  • Once a bat is seen or heard, stop for a couple of minutes to:
    1. Watch and enjoy it!
    2. Watch for AutoID species suggestions from the Echo Meter app. Try to tap the top suggested species (in yellow) when they appear. Callout the top name only to the team.
    3. Tune the Magenta detector to the frequency in the Magenta column on the species lookup laminate so the team can also listen to the bats echolocation calls.
    4. Record the top bat species (only) in the iNaturalist app using the name (and iNat Code) in the green column of the species laminate by following the instructions for your device below:
  • After the couple of minutes is up, move on again.
  • When the next bat is seen:
    • If it is a different species of bat, add an observation in iNaturalist as above.
    • If the same species bat is heard again, ignore it until you have moved 30m+ from your previous observation of that species. If you are 30+m away, stop and record the bat species in iNaturalist as above. It may be a new bat, or you may suspect it is a bat you have seen before doing big circles. Either way, it doesn’t matter, just add a new observation in the new location, then move on again once the minute is up.
  • Within your area, feel free to follow the direction a bat went in, but try not to go over the same ground too much.

At the end of your count

  • After the hour is up, stop recording on the tablet using the red “Stop” button at the bottom right of the screen.
  • Switch off the tablet (press and hold the side power button, then select “Power off” onscreen twice).
  • Switch off the Magenta detector.
  • Return to the central base.
  • Return all the kit to the bat group count leader, and report if any problems occurred.

4/ The close of the count night

All the team’s results are available instantly on the iNaturalist app and website.

Hence the count leader will be able to review and give a debrief talk to include the initial results.

5/ After the count

All the results on the night will be unverified “casual” flight recordings. Some of the species regarded as threatened in iNaturalist may have their locations and time of observation obscured, by moving them to a random point within 10km.

In the days or months after the count experts from the bat group will be able to review the recordings made on the devices, and for the key bat sightings, upload screenshots and sound files, to allow verification of the species from the recordings obtained by the teams.

These verified records will then be uploadable into the Environmental Records Centres databases.

Big Bat Count

Thanks!

The Somerset Bat Group is grateful to:

SERC logo
Hinkley Point C Community Fund
Somerset Community Foundation