How to take part in a Big Bat Count

Signing up

You can sign up either as part of a community group or on a public Big Bat Count.

Teams of between 2 and 6 adults who know each other are ideal. Children are welcome if each is accompanied by an adult.

Before the Big bat count night

Once booked onto a big bat count we ask:

  1. At least one adult (hopefully more) from each team should install the iNaturalist app from the Google or Apple App store on their mobile internet-enabled phone.
  2. Open the iNaturalist app and create a iNaturalist account.
  3. Join the “Somerset Big Bat Count” project in the iNaturalist App.
    • On Android phones:
      1. In the iNaturalist App, tap the three-line icon (Hamberger) in the top left of the screen
      2. Select “Projects
      3. In the Projects screen, tap the magnifying glass in the top right corner of the screen.
      4. In the “Search projects …” box at the top of the screen type Somerset Big Bat Count
      5. You should see a screen with bat records in the bottom half. Click the small grey “Join” button just above the bat records to the left.
      6. Check this button has changed to “leave”. Before tapping the top right back arrow twice.
    • On Apple iOS phones:
  4. It helps with both pre-event communications, and on the night, if the count leader signs everyone up to a WhatsApp group for the night’s count.

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 species it hears.
  2. The second detector (Magenta) is non-essential and a “nice to have”. It can be set to the frequency shown on the tablet, and allows participants to listen to the echolocation calls the bat is making in real-time

Each team is then given instructions and a map showing an area that they can cover. This can be arranged in advance and could be on the teams 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 to avoid creating ultrasound themselves as much as possible. Keys rattling, small change, rustling cagoules, zips .. etc are all common ultrasound sources.

taking part in the Big Bat Count

The aim is for each team to start the Big Bat Count of their area at Sunset, and carry on for the next 90 minutes.

The process each team should follow is:

  • Switch on the tablet by holding power button for 5 secs. Swipe up to dismiss the opening Amazon sales screen:
    1. Start the Echo Meter app on the tablet.
    2. Dismiss the location warning.
    3. Plug in the EMT microphone, this is directional so ensure it is always pointing upwards.
    4. Press the big green round Start button.
    5. Start recording using the round button with red square in it (auto bat ID only works when recording).
    6. If at any time the Echo Meter app freezes during the night, the quickest way to reset is to hold down the top power “on” button and select “restart” onscreen, to reboot the tablet. The follow the steps above again.
  • Switch on the Magenta bat detector, and set it initially to 45kHz
  • Log into iNaturalist on the internet-enabled phone.
  • Aim to cover as much of the area as you can in the next 90minutes.
  • 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. This will usually be rhythmic patterns of sound.
  • Once a bat is seen or heard, stop for a minute to:
    1. Watch and enjoy it!
    2. Watch for AutoID species suggestions from the Echo Meter app. Try to always tap the top suggested species.
    3. Record the bat species in the iNaturalist app.
      • On Android phones:
        1. In the iNaturalist App, tap the three-line icon (Hamberger) in the top left of the screen
        2. Select “New observation“, then tap “No Media
        3. Type the name of the bat name using the iNat code from the supplied species lookup table into the “What did you see?” box at the top of the screen.
        4. Tap the desired Bat species that appears below
          • If the phone does not have an internet connection, the species lookup in iNaturalist will not work, hence type the full iNat bat species name in manually.
        5. If online, tap the big green “Tick – Select” button below the bat picture
        6. On return to the “Edit observation” screen tap the round green tick button at the bottom of the screen
      • On Apple iOS phones:
    4. Tune the Magenta detector to the peak frequency shown on the EMT so you can also listen to it.
  • After the minute is up move on again.
  • When a different species bat is next heard, or a minute has passed and the same species bat is heard again, stop again for a minute and record the bat species in iNat as above. It may be a new bat, or you may suspect it is the same bat doing big circles. Either way, it doesn’t matter, just add a new record, 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.
  • After the 90 minutes are up, return to the central base, return all the kit to the bat group count leader, and report if any problems occurred.

The close of the count night

All the teams results are available instantly on the iNaturalist app. Hence the count leader will be able to review and give a debrief talk to include the initial results.

After the count

All the results on the night will be unverified flight recordings.

In the days 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, to verify the species from the recordings obtained by the teams.

Big Bat Count


SERC logo

The Somerset Bat Group is grateful to the Somerset Environmental Records Centre (SERC) for funding the new equipment used in the Big Bat Counts.