Carrying out a survey
Before the survey
- Select your survey dates. Surveys should be conducted on non-consecutive nights between 1st July and 11th August.
- Check the weather forecast. Avoid surveying in strong wind, heavy rain or if the temperature at sunset is below 10 degrees.
- Check your equipment. You will need:
- Blank SanDisk Extreme 32GB micro SD card and adapter
- Three AA batteries
- Weatherproof case
- Padded envelope
- Guy ropes and pegs (optional)
- Tape measure (to measure deployment height of 2m)
- A way to secure your AudioMoth to the pole (e.g. duct tape or narrow cable ties able to pass through the mounting holes on the weatherproof case)
- Scissors (to remove Audiomoth from pole after the deployment)
- Flat head screwdriver or similar (to open weatherproof case after deployment)
- Cloth (to dry case before opening)
- Survey instructions
- Survey point details form (download here), or a copy of the form you previously completed as a reminder of your survey point location
- Risk assessment form (download here), or a copy of the form you previously completed.
- GPS, or smartphone with GPS app installed
- If you haven’t already done so, gently insert a blank SD card (print facing down) and batteries, and follow these steps to configure your AudioMoth.
- Activate your AudioMoth. Slide the switch to CUSTOM. The green LED will flash every two seconds to indicate that it is sleeping, ready to record. If other LEDs flash, click here to see what this means.
- Insert the AudioMoth into the lid of the case first. Press the circuit board of the AudioMoth into the gap in the foam padding, ensuring the microphone on the AudioMoth lines up with the hole in the lid. Place the pack of silica gel alongside the battery case on top of the lid. This will help to keep the case interior dry. Please make sure the silica pack does not cover the microphone or is placed on the circuit board.
- Attach the box to the lid. Gently press the box down onto the lid (with AudioMoth). Press the lid down gently to minimise air pressure against the weatherproof mesh.
- Place the weatherproof case inside the padded envelope ready to travel to your survey point.
At the survey point
- The AudioMoth will start recording at 20:00, so aim to have it deployed before then.
- Complete a risk assessment. Click here to download the risk assessment form.
- Set up the pole at your survey point. Remember the survey point should not be lit by artificial light and be at least 1.5m away from:
- Vegetation or other obstructions that could mask bat calls.
- Hard surfaces such as tree trunks or walls, which can cause echos that distort recordings.
- Water - the reflections of sound off the water's surface can distort recordings.
- Important - attach your AudioMoth to the pole 2m above the ground, vertically oriented, with the microphone uppermost and facing away from vegetation or other obstructions.
- If this is your first survey, fill out the survey point details form. Click here to download the form. Take a GPS reading at your survey point. Please provide a detailed description of the exact location that you deploy your AudioMoth, so you can find it again next time!
After your survey
- Collect the AudioMoth. The AudioMoth will finish recording at 6:30am so can be collected any time after that.
- If you are surveying multiple squares, please remove the SD card from the AudioMoth, place it in an envelope and label the envelope at your survey location, to avoid mixing up which card came from which site. If you are surveying a single square you can wait until you get home to remove the memory card.
- Open the box. If the box is damp give it a quick wipe before opening it, to prevent water getting on the AudioMoth. Insert a flat head screwdriver or similar into the slots on the side of the box and twist gently. The lid should pop open. As you remove the lid, take care that the Audiomoth doesn’t fall out.
- Remove the AudioMoth from the lid. Hold the circuit board and ease it away from the foam padding. Watch that the SD card doesn’t spring out of its holder.
- Slide the switch to USB/OFF to turn the AudioMoth off. As you do this, count the number of times the red LED flashes. If the battery voltage is below the minimum threshold it will flash rapidly for about 2 seconds, and you should replace the batteries and reconfigure the AudioMoth before the next deployment. If it is above the minimum threshold it will flash from 1 to 4 times depending on battery voltage, with 4 indicating full. Remember that if you do remove or dislodge the batteries you will need to reconfigure the AudioMoth.
- Remove the memory card from the AudioMoth. To release the microSD card press down gently onto the card and it will spring out of its holder. Remove the card and place the card into its black plastic adapter. Place the adapter into one of the Freepost envelopes provided and write your survey point name on the back of the envelope. Without your survey point name we will be unable to process you recordings. Post back to BCT as soon as possible, you don’t need to wait to complete subsequent nights of surveys.
If the batteries have sufficient power and are not removed or dislodged then the AudioMoth with remember it’s settings and will not need to be reconfigured. Insert a blank SD card and you’re ready for the next survey.