Mary Clapp
- @mkclapp
- | she/hers
Hi all! Longtime ARU practitioner here, but new poster to Wildlabs. I am working with some collaborators in northern CA who would like to expand their ARU monitoring into the winter season and are looking for advice on "winterproofing" ARUs. They are using Wildlife Acoustics' SongMeter Mini 2s and monitor in somewhat remote forested environments (so strapping their recorders to small trees). Depending on the winter, precip usually falls as either cold rain or snow. Heavy snowfall is possible but highly variable across years. Because the sites are fairly remote, they are prepared for the possibility of the recorders being out after exceeding battery life/storage space in the event that winter weather prevents them from accessing them. I've deployed recorders in every season except winter, and wanted to provide them with as many useful, field-tested recommendations as possible so they minimize the possibility of units getting destroyed or data being lost. So far, we've got:
-accommodate longer time between visits with a sparser recording schedule
-include desiccant inside units to prevent moisture buildup
-consider building "roofs" with halved PVC pipe to mount on tree above unit
-increase height of recorder from ground to above estimated max. snow/drift height
-orient microphone downward to be shielded by the body of the unit
Have others made similar &/or additional accommodations for winter deployments? Thanks for any advice!
7 November 2024 8:47pm
Depending on how cold it gets too, you may also want to check the ideal temperature range of the batteries and SD card you plan to use, as these can also be influenced by cold temps!
Per the Wildlife Acoustics website, SM Mini 2's have this range: -4°F to +185°F or -20°C to 85°C.
17 November 2024 3:47pm
Hi Mary, I don't have any direct experience with the Mini 2's, but I have lots of experience with Owl Sense in the winter in Montana. One of the biggest factors is going to be the batteries. Alkaline batteries are terrible in the cold. Going with lithium batteries is going to be almost essential. That's one of the primary reasons we chose to use rechargeable lithium batteries over alkaline for Owl Sense.
I generally haven't had an issue of ice or water build up in our acoustic ports, but it is a concern. I think a roof or downward orientation would be well worth it, especially in the Sierras.
Troy
Akiba
Freaklabs
18 November 2024 1:52am
Depending on the conditions, it'd probably be useful to run the system inside the refrigerator (approx 3 deg C) or freezer (approx -20 deg C) to see how it performs in those temperature environments. The -20 to +85C temperature range probably comes from standard electronic IC temperature ranges. However at cold temperatures, things like mechanical and electrochemical parts (batteries) get funky. A microphone depends on a thin moving actuator to generate the sound vibrations that get converted into voltage. At low temperatures, it may affect the frequency range of vibrations, etc.
Hope this helps.
Akiba
Carly Batist