Whilst wildlife is obviously intelligent, an intelligent wildlife detector uses so called artificial intelligence to analyse audio recordings and calculate probabilities that a certain species was roaming around in the near vicinity. Most importantly, the software is open source so it can be adjusted to work in any geographical area on different levels. For example, here in the UK, the system is set up to detect my local bat species and I can also select genus or even just animal, in which case it will give results according to whether the audio was of a bat, a rodent or a cricket.
Obviously not everybody is going to have the skills to hack the software, but to someone who does have the skills, it's actually not that hard to train the system to work on, for example, the local birds in the area. The hard part is actually getting all the recordings and sorting them into the different species.
So, assuming the software is now tuned on the local animals / birds, the device would now be deployed out in the wild to seamlessly record chunks of audio and analyse each one of them on the spot to try and find something interesting. If the system finds something, even just a snapping twig, it will save the audio file, renaming it to 'rubbish' or such like. If it finds nothing, it will delete the file, saving space on the file storage device. More to the point, if it finds an interesting animal it will rename the file with the confidence of successful classification and the animal name and the date. Eg 95%_Nattereri_02:07:2020_18:44.wav. This saves a huge amount of time manually sorting through hundreds of Gb of data and manually naming files.
The device itself has a lot of other functions, including displaying the data in a dynamic bar-chart on a small touchscreen. There's also the capability to transmit some of the data to the cloud via a radio link or the 4G cell phone network although much of our wildlife has the tendency to inhabit rather remote locations, far away from human communication infrastructure. For example, connection to the cloud is not going to work in the middle of the Amazon rain forest without a more expensive satellite transmitter.
It is possible to leave the device out in the wilderness for a long period of time but it would need an external battery and solar panel to keep it alive. It would also need to be hidden and protected from theft or tampering, whether that be from human beings or other curious wildlife.