BattyBirdNet-Pi

Its 7 or 8 years since I last did any bat monitoring.

 

To be honest, I got a bit bored with it.

But now I've set up a BattyBirdNet-Pi system ...I'm back!

The difference this time is that I'm using a system based upon BirdNet, so data is presented in a better way, and calls are identified using much smarter software.

BattyBirdNet-Pi seems to be based on the McGuire version, presenting data on a daily basis. However, bats are creatures of the night, so I've hacked the code into a 'Nightly' format.

I'm currently testing with my old Dodotronic Ultramic hanging out of an upstairs (1st floor) window. I'm using a Raspberry Pi 4 with only 2GB RAM, which some have suggested might be too little. But it seems to cope ok inside a 'heat-sink type case' where the temperature remains around 60'C for a 20'C ambient temperature.

Initial impressions are good, although I seem to get an awful lot of saved analysis images; several within a second, which just look like duplicates. So I probably need to tweak a few settings.

Many detections are clearly bat calls, but some just look like noise, so I'm running with 90% minimum confidence to reduce these (...actually, I'd quite like to eliminate these).

I have no desire to save hundreds of spectrogram images/call, so the built-in Database Management tool is very handy for doing bulk deletion of records, but I still have to go through the BirdSongs directory and delete files.

a few captures... 

 

This call sequence is reported as a Nathusius Pipistrelle; it starts with a typical feeding buzz, where it emits pulses closer & closer together as it chases some kind of flying insect, before dropping the frequency at the very last minute. It then resumes just-looking-about mode.

Same again, but this time from a Soprano Pipistrelle. The basic call is about 10kHz higher in frequency.

Another Soprano Pipistrelle, this time with a couple of lower frequency, social calls. These are so loud, they overload the system. Its a good job we can't hear much above 20kHz as this would be deafening to us if we could.

Two sopranos arrive each evening about 20 minutes after sunset. It looks like they find the time to chat while they hunt!