Ultrasonic Bat Recordings – How to ID.

I have some ultrasonic bat recordings from an old Wildlife Acoustics recorder.

But no software to interpret. Unless I pay hundreds of pounds for a moment of curiosity.

Any Bat experts here who could suggest something free or online?

The machine still works and we had loads of bats in the garden last night.

Any thoughts.

I think you might be able to use Audacity in its Spectral Analysis mode to display the frequencies of the bat calls and then look up which bats produce those frequencies:
https://support.audacityteam.org/audio-analysis/spectral-analysis

Do you know how your bat detector works?  Some use heterodyning, some use frequency division.  If your recorder is “old” then it’s probably not recording the actual frequencies, but some interpretation of them.  You’ll need to bear this in mind if you use a spectral analysis of the recordings as I’ve suggested above.

There are a couple of free Raspberry Pi projects for doing exactly this. I’ve looked into doing it before as the mrs is a bat-nut & we get loads in our garden, but balked at the cost of the USB wide-spectrum ultrasonic mic (about £300!)

http://www.bat-pi.eu/EN/index-EN.html (this looks the best/fully featured)

https://www.instructables.com/Intelligent-Bat-Detector/ (you could probably just download + run the audio extraction software & classifier that the guy has developed, since you already have recordings – this might be the easiest option, assuming you are OK with Pi stuff/linux/coding or willing to learn!)

Depending on the age it will probably be an SM (Song Meter – developed for recording bird sound, but then adapted for bats (SMBAT). They then released a handheld version EchoMeter (EM) and then a version that plugs direct into handheld phones/tablets. These have then been updated over time. They are a full spectrum recorder, rather than heterodyne.

Wildlife Acoustics do their own Kaleidoscope software (Lite version is free) which if you just want a look see is perfectly useable.

Its been  a while since i helped witha bat survey but i think nerd pretty covers the biggest clue.

Take a guess at what you might have based on location, habitat etc

If you have a date and or time for the recording you can use proximity to dusk to give you a good indication of which species, especially if you have long recordngs you should get “waves” of different species.

Frequency will finalise your best guess. However, it depends what your audio is. If its been adjusted prior to recording you might have to do a bit of digging to find out how the compensate from any frequency adjustment (lowering so humans can hear it)

If they are singular noises they are commuting if you get a whole bunch of noises that aren’t farty they are hunting the fart noises are them catching food.

Hmn somewhere along the line my caveat seems to have gone walkies.

I could be talking out my arse fully or partially.

If only it was that easy Josh.

If they’re full spectrum recordings BTO Acoustic Pipeline is your friend.

https://app.bto.org/acoustic-pipeline/public/login.jsp

Get a free account, get 100 credits for auto ID, select Citizen Science/share data, upload recordings, get results with probability score for species.

Job done.

Thanks guys.

Box is a Wildlife Acoustics son meter mini bat

Wav file to follow.

Last nights Bat 🙂

Looking into trying to ID.

The meter is a Wildlife Acoustics, Song Meter Mini Bat

The recording if anyone wants a play… ID

https://file.io/eVQO6cyMfqTm

Interesting, how did you end up with an SM Mini? It’s a deployable-static type detector, we generally use them in longer term surveys for bat activity where we leave them in place in woodlands etc.

Thing is, they aren’t designed to be that user-friendly compared to the more hand-held detectors that have easy-access apps and auto-identification. That is going to make it harder.

You say it’s old – the WA SM Mini only came out in 2020, if I recall.

If you’re using a Song Meter you’d be better using Wildlife Acoustics software. You can download the free version here:

https://www.wildlifeacoustics.com/products/kaleidoscope/kaleidoscope-lite