Wildlife Acoustics EM3

Wildlife Acoustics EM3 Active Ultrasonic Bat Detector

From: http://www.wildlifeacoustics.com/

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


EM3 packed with everything you need to start recording (gps optional extra)

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.

EM3 first look

EM3 up close

First impressions are here.

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.



Dodotronic UltraMic200k digital USB microphone


Dodotronic UltraMic200k digital USB microphone

From: http://www.dodotronic.com/index.php?center=11&left=1

Pro’s: Real time, full spectrum recording. Futureproof.

Cons: Needs netbook and software so not suitable for transects. Not suitable for all UK species

Dodotronic UltraMic200k

Dodotronic UltraMic200k

Although not strictly speaking a bat detector, combine the Dodotronic UltraMic200k with a netbook and you’ve got a  light and portable mechanism for capturing full spectrum echolocation in realtime (which is where bat detectors are heading) and all for circa £500.

Ultramic200k and Netbook

Ultramic200k and Netbook

With a sample rate of 200k you’ll only record sound up to 100khz with the UltraMic200k so for some species you’re better off spending the extra on the UltraMic250k which captures sound to 125khz. Sound can be captured using BatSound, SeaWave or other software.

Sure it’s more suited to static surveys (I’ve been testing this one at swarming sites), and identification during data sifting is going to take longer; to say nothing of data storage issues associated with large files.

But, and this is a big but, I believe we’re on the cusp of the next stage in bat identification with automatic identification software just over the horizon. Couple one of these mics with a smartphone or tablet running the right software and you’ve got a powerful, affordable and accurate method of surveying and identifying bats in flight.

Link to the User Manual

Expect to see a Ultramic250k review soon.

Anabat SD1 and SD2

Anabat SD1 (now superceded by SD2)

From: http://www.titley-scientific.com/uk/index.php/anabat-bat-detector

Price: £2062 for SD2 and pda kit

Pro’s: Versatile, small data files.

Cons: microphones sensitive to water damage, cost compared to rivals.

Anabat with pda

Anabat set up with gps and pda

The Anabat is a zero crossing bat detector from Titley Electronics and has long been the workhorse for bat workers needing static longterm monitoring. It’s a versatile bit of kit, capable of either static programmed use or coupled with a pda and gps or just a gps to record transect surveys.

I’ve been using Anabat SD1’s and SD2’s for quite a few years now and up until recently relied on them for most of my survey requirements. The live display of sonograms on the pda is a great tool for instant in the field ID and also invaluable as a teaching tool when running bat detector workshops.

The zero crossing analysis files produced by the Anabat are tiny (think kb’s not mb’s) allowing long term monitoring in busy active sites without the need of purchasing multiple expensive data cards. Coupled with a decent external 12v battery it’s possible to leave the detector running up to a month without filling a 2gb CF card. Workflow using AnalookW to analyse all those collected files is reasonably quick too. Note however this is a very visual system with little useful audio output either in the field or back at the computer.

Hi and Lo MIcs

Ergonomically  and weight wise that Anabat and pda are going to be noticeable if you’re carrying one all night although easy enough to handle in the field.

For european batworkers the two mics of interest are the standard mic and the hi mic, the hi mic is recommended where Horseshoe bats may be encountered or where you’re using an extension cable longer than 1 metre.

For me the weak point of the system is the microphone that needs careful thought to protect it from water contact when deploying it in the field. This is easy on open sites where a cover and 45degree sound deflector can be used to keep the mic sheltered. Underground in typical UK 99% humidity conditions I’ve found condensation eventually builds and takes the mic out. Some users compromise recordings and sensitivity by covering the mic in clingfilm to avoid this.

In use with a pda I’ve also had the system corrupt data files in areas of high multiple bat species feeding activity, a frustrating thing to find at the end of what you think has been a good nights survey. Having started using an EM3 this year, I’ve now gone back to connecting the Anabat to a gps only which when combined with BatNav software is a great reliable tool for simple and quick transect work.

In spite of the above drawbacks I still carry two Anabats in my survey bag because they are just so useful to have and use. The anabat is a great system for long term static surveying with low power use and low data storage requirements but with a few tweaks it could be a lot better. In an time of increased competition I’m looking forward to seeing the next iteration of this detector. If it follows the Anabat Roost Logger I’ll be more than happy

Anabat example sonogram

Anabat example sonogram

Anabat users are advised to keep an eye on Chris Corben’s site for the latest firmware and software.