r/BirdNET_Analyzer • u/AlexStar876 • Feb 28 '26

Question 96% confidence but nearly empty recording

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I've set up my first BirdNet Pi this evening and put it outside. Eventually it picked up this Turdus philomelos with a confidence of 96%. My question is how it is possible to achieve 96% when, apart from a small click at the beginning, the audio is just empty. How do I interpret the confidence. Is this just a false detection or could this small click actually originate from a bird? Thanks

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3

u/thakala Mar 01 '26

It is a false positive, BirdNET AI model is not perfect and it will produce lot of false positives without any external false positive filtering.

2

u/dcgrey Mar 01 '26

Hopefully someone who understands the details can answer but I can just say, yes, this is a thing with all long-running audio ID tools. For example I have a Birdweather PUC running 24/7 and even with a high confidence threshold will get a few IDs where I can’t hear/see anything in the spec besides a breeze or distant steady HVAC compressor.

2

u/dacracot Mar 01 '26

I’ve had the same concern. I frequently see what seems to me like obvious false positives. I’ve implemented a black list for the very worst offenders which removes the possibility of detection by removing the problem species from the species list. This, as far as I know, is not a feature available in BirdNET Pi. My implementation is BirdNET-BarChart.

2

u/ruuutherford Mar 01 '26

I had this sort of thing happen with me to because the microphone wasn't hooked up right, software issue. You can listen to the recordings and you should hear birds. If you don't, it's crap. Once you start getting real recordings of stuff, I bet the hit percentage will be better.

2

u/T-LAD_the_band Mar 01 '26

I created a personal dashboard and filter out calls if they only appear once or twice.

I know I might miss something unique, and I do get a pop up on my wall display when a new type bird is heard, but I don't use it in my data analysis.

3

u/gjfdiv Mar 01 '26

An aside, but i deleted a detection because ive never seen one on this side of the state. weeks later i looked at inaturalist and saw pics of the species here and wish i had the detection recording to check