Wildlife Acoustics EM3 Active Ultrasonic Bat Detector
Price: £979.99 plus £199 for GPS
Pro’s: Compact system, full spectrum and zca recording, simplicity.
Cons: ZCA file production needs tweaking, gps noise interference
The Wildlife Acoustics EM3 is a full spectrum bat detector / recorder with the capability to georeference recordings via an optional plug in gps unit. One of the bonuses from a workflow point of view is the ability to record in wav/zca setting which produces both a realtime full spectrum recording and a zero crossing data file suitable for analysis in AnalookW. This in theory allows you to process zca files to identify easier species such as Pipistrelles but have the use of full spectrum calls for more in depth analysis of harder to identify species.
I’ve been using the EM3 for a full survey season now and have to agree with Dave Dodd’s that whilst it’s the detector I reach for automatically for most work it is also capable of slowly irritating me over the span of a night.
Ergonomically I’m happy with the package of EM3 and gps puck, it’s easier to hold and lighter in the field than an Anabat, gps and pda. I’m still working on eliminating the inevitable sound files created as you shift it in your grip, something a silicone sleeve might resolve. The detector is a perfect set up for transects and with the option of a seperate wired input for an additional microphone should work perfectly for car use too. Although capable of static programmed surveys I think I’d rather leave that to the SM2Bat+ which is designed for the job.
Recording wise the detector took a fair bit of tweaking in threshold settings before I was happy with the production of zca files, this isn’t such a great issue now that Wildlife Acoustics have now released Kaleidoscope a very handy utility for converting wav files to zca that seems to produce very reliable results. Recordings are crisp and clear and the live black and white sonogram display is great for in the field ID of easier species.
The main advantage over the Anabat SD1 and pda is the lack of connections and potential for issues arising from them. Previously with the Anabat SD1 there were weak points between anabat-pda, pda-bluetooth gps that had the potential to decide out of the blue to not talk to each other; a frustrating scenario when you’re out on site and in the dark. I often carried a separate gps and serial lead “just in case”. With only the gps puck to plug in to the EM3 that’s all disappeared, I no longer have that worry at the back of my mind.
I’ve found I tend to monitor calls in the EM3’s RTE mode, effectively a realtime time expansion and keep the four option buttons programmed to flick between 20,45,55, and 110khz hetrodyne modes. A nice and simple system to flick between even in dark conditions.
All good so far. So that annoyance?
It’s a frustrating one; without the gps plugged in headphone sound is superb but once the gps connects it’s a different matter with a low level variable shussing feedback that inevitably becomes a distraction. This seems to happen regardless of whether you’re listening in hetrodyne or rte mode and is the only downside to what could be a very capable detector. Hopefully it’s something that can be cured with a frimware update, support is one thing Wildlife Acoustics have certainly got dialled with user forums and firmware updates.
*Update: After speaking to Sherwood from Wildlife Acoustics at the BCT National Conference it appears the gps noise issue is to do with hardware so unable to be solved by software. It’s a niggle we’re going to have to live with.