@nprofile1q... I'm using AudioMoths, specifically the AudioMoth Dev board plugged into a battery pack with three rechargeable AA batteries and connected via its headphone jack to a better microphone (AOM-5024L-HD-R, which I'm told is, or at least was, the microphone specs inside the DOC AR4 units). That's all stuffed into a small waterproof Systema box. My wife came up with the set up (she's the bird audio expert in our family). I can send you the complete parts list if you like.
As for software, the AudioMoths come with software to program them. I've been using Cornell University's BirdNet to auto-detect the bird songs in the recordings, while I wait for the more NZ optimised systems that are being worked on. BirdNet makes mistakes (eg it frequently confuses korimako and tūī) but it's generally pretty good (and excellent at the exotic birds).
The hidden cost in all this is storage. I've had 14 pairs of units (day and night) running in the Port Hills for the past 10 months and I'm at about 5 TB of storage. It's going to add up fast if I keep this going long-term. Earlier this week I wrote a bash script to convert the WAV files to FLAC to save some space.
https://www.openacousticdevices.info/audiomoth#EcologicalMonitoring #AudioMoth #birds