I'm new to recording bat sounds and working with the Audiomoths and i am trying to figure out the best settings to record bat flight and feeding activity. I got advise on the settings from people who worked with them previously to maximise the battery life, since i want them to record for about two weeks.
So far i have the settings on 192kHz with medium gain. Recording from 21.30 to 5.45 with a high pass filter at 16kHz and an amplitude threshold of 2048. These settings seem to be working fine, but i'm unsure about the sleep/record schedule.
I have played around with two AMs with different cycles; one on a 10s/5s and one on a 50s/5s record/sleep period. In the first case i had around 3000 files of very short recording (max 3 seconds), whereas the second had about 1000 files up to 8 seconds long. Both recorded during two nights. With both settings there seemed to be only one recording per record cycle. How does this work when there are two seperate instances of bats passing during a long recording period? Does this produce multiple files or does it combine the recordings into one longer file?
I have seen people use 4minute/1minute cycles or even 1h/5s cycles and cases where they use 10s/5s. I assume it differs a lot depending on what type of activity you want to record but i'm curious about the pros and cons of such schedules.
The long recording periods must be taxing for the battery life. Since i want them to last for 2 weeks this might not be the best option. However, the massive amount of small files isn't ideal either.
I will be recording in an area with few bats, so in case a bat passes I dont want to miss it due to a long sleep period. Additionally, I have heard that a short sleep period (1s) can cause problems where the file isn't properly saved.
Thanks in advance for any advise on this topic!
Great. We normally end up with T.WAV files that are about 1/20 to 1/100 of the size of the equivalent continuous WAV recording depending on how many bats come past and if the AudioMoth has triggered on other background sounds. Reducing the amount of data that is written to the SD card also yields quite a significant energy saving.