Carmen Gavin Vanegas
- @cvanegas
- | she/her
Hi everyone,
I am a high school science instructor, and my students are carrying out a bioacoustic monitoring project with Song Meter Mini 2s and Song Meter Bat 2s at a restoration site they work at near the city. The goal is to identify bats, flying squirrels, and birds using the site to inform future restoration work to support these species. Researchers in my area who have done acoustic monitoring with these devices recommended placing them above the vegetation in the prairie and below the leaves of trees in edge habitat due to echos and issues with quality of sound files, but that means placing them in a more visible position.
I would love to hear any tips you have for securing the monitors in an urban park where people are likely to see them. I did order the padlocks and cable locks available from Wildlife Acoustics, but am not sure we will have a suitable attachment point for all of the devices (some will be deployed in a prairie, and the city said we cannot install any poles). I also know cable locks are easy to cut and are more of a deterrent than a guarantee that devices won't be tampered with or stolen. I appreciate any tips or advice. Thanks!
13 March 2024 3:01am
Hi Carmen,
I would recommend you and your student do a trial run by installing your ARU devices in the most "secure" position (below prairie vegetation, among the foliage, etc) and its alternative for a short period (a few hours); and check the quality of the sound. If you found no significant difference, especially for whatever analysis you are doing, then there is no need to risk losing the devices whatsoever.
I personally don't think such placement will affect the recordings too much, except maybe for the bats, which I do not have much experience with. I did Passive Acoustic Monitoring in a tropical forest full of poachers, with a history of park management losing their camera traps every time they did a survey. I decided to install my ARU on a tree trunk around the breast-high in the densest area possible off the path, trying to not cut any branches or bushes. There is a concern about the foliage affecting the sound reception, but in my case, I did not find any differences. The key thing is to make sure no branches or foliage can touch and scrape any part of your devices, which will make an annoying scraping sound on windy days.
13 March 2024 7:10am
Have you tried my Raspberry Pi ARU yet? You can build one with a high end microphone (The bulk of the price) for less than 100 euros. With a low end microphone I expect around 50 euros.
And that price is including a GPS for time synchronization. If you had the pipeline you could in principle do real time TDOA sound localization. The cheap price comes at a cost though, you would have to replace the batteries a bunch more.
13 March 2024 11:01am
If you have a system with a GPS, on the Pi based system this would work in any case, then you could effectively geo-fence the unit and send out a lorawan alert if the device moved (And they didn't immediately disconnect the battery). You would of course then have to "Add" a lorawan microcontroller to the system. it would still be a cheap system and it would actually work.
If course, there's the classic question, what do you do then? Are you living close enough to be able to respond ?
If the city had cameras and where very enterprising (Which I seriously doubt). Then you could couple up my security system and send real time video alerts if intruders entered the area where the device was hidden.
19 March 2024 7:57pm
This new paper on effects of receiver height might be useful!
Iglesias-Merchan, C., Llusia, D., & Márquez, R. (2024). Importance of the receiver's height for transmission studies in acoustic ecology. The Journal of the Acoustical Society of America, 155(3), 2065-2074.
Panji Gusti Akbar