The PippyG is a low-cost, static, passive bat detector made by Apodemus. The construction consists of a Raspberry Pi board with an additional ultrasonic microphone. The unit was designed to open baseline monitoring of bats to landowners, researchers, and the wider public, aiming to be as accessible as possible. Requiring only the device, a micro-SD card, and either a USB-B battery pack or 3 AA batteries. Analysis is easy with the PippyG as recordings are formatted ready for the BTO pipeline, a free online platform for auto-analysis of ultrasonic bat calls, providing species ID, and even behavioural tags for each call (see table below).
Currently, there is no official waterproofing option. However, this leaves the option for experimentation open. A few makers have very kindly created freely available 3D print designs if you have access to a printer, otherwise, I have heard of people trying various options, from leaving them out as is to using a plastic takeaway box with a microphone-sized hole drilled in.
Unfortunately, I do not have access to a garden or any land to demo the PippyG; instead, I had to settle for the alleyway, which my flat backs onto. A Good test for urban environments where most of us (and some bat species) spend a large proportion of our time. I opted for a setup using a battery pack and a long USB-B cable, which I attached to the PippyG and used as an anchor to hang out of my window.
Choosing the settings is simple and easy using the Pipistrelle app available on both the Google Play Store and the App Store. I decided to test for 2 hours from 22:00 till 12:00, with the trigger setting at 72 (considered low, but I was wary of the rabble emanating from the pub garden next door). Once I decided on the appropriate settings, I held the speaker of my phone to the mic and “chirped”.
The concept of chirping was a new one to me, but it’s simple and fantastic. Rather than connecting directly to the device using Bluetooth to establish your desired settings, the “chirp” encodes the settings into sound waves that the Pippy G picks up using its built-in mic.
The device flashed, indicating it was ready and the “chirp” has been successful. Time to hang it out of the window and wait.
The following day I excitedly transferred the data from the PippyG onto my computer, ready to upload to the BTO pipeline.
And the results are in…
One species of bat, A Common Pipistrelle, most likely emerged from my upstairs neighbour’s roof. Looking at the results, it was in a feeding frenzy with 56 echolocation calls recorded in 2 hours. Interestingly, even though the device was set to record at the ultrasonic level, it still picked up a few bird calls, most likely the seagulls that like to occupy the rooftops on either side of the alleyway.
In the future, I would love to put it to the test with a longer deployment in a less urban environment with the hope of catching more of the 18 bat species the UK has to offer.