I’ve been having a play with the free trial of Kaleidoscope software from Wildlife Acoustics. This was partly prompted by the courses I’ve been running on behalf of BCT for some of the larger consultancies who generate far more data than they can ever analyse manually, so they are very keen to embrace automated processing software. To test it I’ve run through some 10,000 files that I’ve manually looked through so I know what’s on them. These are mostly from a Pettersson D500x, but there are also a large number of files from the SM2BAT+.

The basic interface is modular, in that the file conversion utility is free. You can use this to batch process and convert .wac files to .wav and also zero crossing files. To this you can add the Kaleidoscope viewer (£325) or opt for the Kaleidoscope Pro version which includes the viewer and a set of classifiers for UK bats (£755). You can download and try Kaleidoscope pro for 15 days to try it out, which is what I did.

To start with, there has clearly been a lot of time spent on the interface. It works nicely, is simple and does the job. One minor irritation is that you can select an output directory that is above the data directory. In other words, if you data is in C:\field_data, you can’t put the results either in that directory, or in one above it such as C:\field_data\results. They have to go into a directory at the same level or below the one you are processing. If you are just processing files to classify them, don’t check any of the output file formats unless you want copies of the processed files in your results folder. With 60 GB of data to process, this can cause havoc!

If you are classifying calls, you have the option of switching in and out any of the current 11 species classifiers. Myotis is still lumped together (sensibly), and the newest addition is a classifier for Nathusius’ pipistrelle. There are two classifiers for lesser horseshoe, a normal one and one for the 192 kHz recording mode where lesser horseshoe calls would be aliased.

To start, you select the directory on the left hand side of calls you want to process.  You can also include sub-directories from this which is a nice feature meaning you can batch process A LOT of files. You select or make an output folder on the right hand side for the output files, select the classifiers you want to use (i.e. the species you want to look for), hit ‘process files’ and go away for a cup of tea, lunch or a mini-break to a top European destination depending on how many files you need to process. For my files it took around 10-15 minutes per night of data, which for this type of processing is very very fast. However, as this is very CPU intensive, I couldn’t use my PC for anything else while the processing was going on. If I did try, Kaleidoscope threw up a few file I/O errors claiming that the file was too big to process. So best to leave it to do its job. If you have a lot of detectors for a lot of nights, this could take you a few days, so be mindful of that.

The output is presented as a table, but also output as a .csv file to your selected results directory. It tells you the file name, species ID, number of pulses and certainty of identification. You can then click on each entry and that file opens up in the viewer which is a really nice feature so you can check it and if necessary amend the identification. You can also click on the column heading to sort by species to look for anything that is not a pipistrelle. I have to say I’m not a great fan of the layout and look of the viewer, but then I’ve used Batsound for years so am more used to that. I’m sure you can customise the viewer to suit the look and layout you want.

So how did it fare on identification? Well, I have to say it did pretty well considering. It’s not overly keen to classify things, which I like. I have used other software which is intent on suggesting the most bizarre species. Nothing too odd came out of this, and it did seem to deal quite well with the dreaded pipistrelle social calls which other software turns into barbastelles among other things. There was a category of ‘noID’ which is where the software admits it can’t identify something, which again is pretty honest.

It is quite keen to pull out P. nathusii (I downloaded it with the nathusii classifier). So a P. pipistrellus with FmaxE at 41 kHz was a nathusii, with high confidence which it clearly was not. This happened quite a lot where groups of common pipistrelles were flying together and shifting their call frequencies away from one another. Personally I wouldn’t take any nathusii classification at face value without checking it manually.

It struggled with the big bats group. Obvious N. noctula were right, but some serotine/leislers FM-QCF calls were attributed to N. noctula when they were too high for my liking. Also some higher QCF noctule calls at 22-23 kHz were attributed to N. leisleri when the IPI was far too long to be leisleri. Again, I’d like to have a look manually at all the big bat classifications.

One bizarre occurrence was that high amplitude recordings of P. pygmaeus which had nice harmonics at 110 kHz were picked up with 70% plus confidence as lesser horseshoes rather than pygmaeus, even though they were lovely pygmaeus recordings.  P. auritus also cropped up a few times in the recordings but it was usually a Myotis, so that needs watching. It did a pretty decent job of ignoring pip social calls rather than attributing them to something, again which is pretty good.

The software did fail to deal with recordings which had more than one species in them, but that’s not terribly surprising.

One potentially more alarming issue was that I had about five nights of data from inside a church which had a brown long-eared roost in it. The software failed to find a single long-eared call even though there were plenty of classic (weak) calls in the recordings, as well as the usual social calls. This happened even when I turned the sensitivity up on the classifier (there is a more accurate/more sensitive switch).  I wouldn’t be happy using this to find long-eared bats in barn conversions for example without manually going through the data. I even edited out good long-eared recordings and put individual files through. It wasn’t that it didn’t classify them, it just couldn’t find them.

In summary, it did a pretty good job as a pipistrelle filter, and can be great for sorting out other species to check manually, but I’d still want to have a look at any file that wasn’t a P. pipistrellus/pygmaeus to check the classification. The software can save a great deal of time, and in some larger scale surveys may be a necessity, but I would be reluctant to accept any non-common or soprano pipistrelle identification at face value without having a look at it first.

D500x firmware upgrade

The new D500x firmware version 2.2.2 has been released. The trigger sensitivity option now allows for better rejection of noise events and there is a new timer option that can start and stop the detector relative to sunrise and sunset when you put in your latitude and longitude. Both are very welcome additions.

One of the most useful features I've found though is that the log file created during recording events shows the battery voltage through time. This really helps in choosing the right batteries for the duration the detector is used. I trialled it with an external battery case with four NiMh 'C' cells which gave out 4 x 1.2v = 4.8 V. You could see the voltage change through time until the detector got to 4.2 V when the detector stopped working. I'm sure with four alkaline C cells at a total of 4 x 1.5v = 6 V it would have been fine.

While we all want to be responsible and use rechargeables, it often just does not work with devices like this when you need them to be reliable and are not checking on the batteries all the time. Most of my NiMh AA cells are unusable after two seasons as they suddenly lose charge. I think the best power source is still a 6V lead-acid battery for long periods in the field.

I've had some lovely long-eared recordings from my D500x from a church recently, plus a load of very varied but wonderful social calls. Long-eard bats are certainly very talkative.

I've been looking into getting a remote monitoring system for bat echolocation. I ruled out the EcoObs batcorder due to cost, so it was between the Wildlife Acoustics SM2+ and the Pettersson D500x. It was not an easy decision, but after weighing up cost, recording quality, expandability and integration into Batsound I went with the D500x. This is to deploy at a couple of sites this summer to be used in conjunction with transects so it's likely to be out in the field for a few months. Needless to say, I'll be testing it in the garden first, let's see if I can get further than the usual species list of P. pipistrellus.

More writing for the BCT 'Planning and Designing Large Scale Surveys' course. Slightly complicated by the fact that the Infrastructure Planning Commision (IPC) which would have dealt with major infrastructure projects will hand over it's responsibilities to the Planning Inspectorate on the 1st April 2012 as part of the Localism Act (2011). This means that the planning process (and hence enivironmental impact assessments) are somewhat in limbo until there is a bit more of a steer on how the new processes will work. At least the course will be hot of the press.

Two new snippets of interesting photography news over the past week. The first is a rather sad one in that Kodak will discontinue all E6 reversal films (more commonly know as slide film). While I moved over to Fuji colour reversal filsm some time ago, this is still sad news as it puts further pressure on maintaining E6 processing lines in photo labs. While I admit that taking, processing and then scanning 35mm E6 film is a bit of a chore when I could have just taken digital, the quality from medium format prints from slides is just staggering. It would be a great shame to lose that option.
The other piece of news is that Nikon have finally released the long awaited sucessor to the D700, called unsurprisingly, the D800. This has the frankly staggering resolution of 36.3 Megapixels. Nikon has rather wisely kept out of the megapixel race for some time, but this does put the cat among the pigeons. I have to wonder what anyone will do with that resolution. My favourite lab, Peak Imaging uses a Durst Theta printer which outputs at 254 dpi. This means that the rather meagre 6 MP of my D100 can print perfectly good full frame prints at 12"x8", which is the usual size I print to. A D700 at 12 MP can print to 17"x11" which is quite big, but nice for hanging in a large room, while the new D800 could print to 29"x19", which to my mind is a little over the top unless you want to make a billboard. You could of course say that it gives you more options to crop in post-processing, which is of course true, though to my mind it is always better the get the shot right 'in camera' in the first place.

The warm end to February has also brought out the bats, with several sightings of pipistrelles in the evenings. I wonder how they fared this winter, being mild then very cold for a short period. Not an easy thing for a hibernating mammal to deal with, unpredictable winter weather.

Spring is most certainly upon us, judging at least by the number of squashed amphibians on the local roads, and also by the sudden influx of things to do and the exflux of time to do them in. I'm starting to get to grips with the 'Planning and Desiging Large Scale Surveys' course that I'm writing for the Bat Conservation Trust (BCT) in collaboration with David Shepherd of Baker, Shepherd and Gillespie in Oxford. While most of the surveys methods are very familair to me, the planning process for these large projects will be an interesting thing to learn about.

The Wildlife Acoustics new EM3 bat detectors is now available from nhbs at a tad under £1000. There's a lot of technology in there and I haven't got to grips with the full specification yet, but it looks like full spectrum 16 bit 384 kHz sampling rate streaming to SDHC card, plus being able to listen in frequency division and heterodyne. The big difference is that it also has a screen that shows spectrograms in 'real' time. Not sure how useful this would be in the field compared with off-line analysis in batsound or similar, but it certainly looks good! It's not the first sound analyser for bat echolocation to be able to give a visual output in the field mind you. That honour goes to the Ultrasound Advice 'PUSP' or portable ultrasound processor which has been available for well over ten years now. The technology is looking pretty long in the tooth now, but it's still a very flexible instrument, especially for ultrasound output in the field.

EM3 bat detector

Was sent the latest update from Wildlife Acoustics on how their new SM2BAT+ remote bat echolocation recording device fits into the survey requirements for the endangered Indiana bat. This is not something that would really affect us in the UK, but they do make a big thing about how their microphone is 'omnidirectional' compared with the more traditional directional designs. This is an interesting comment as the directionality of microphones in the ultrasound range is largely a function of their size and geometry, and that's a basic law of physics. They are understandably cagey about talking about their proprietry microphone technology, but we've spent a lot of time and effort on making microphones as omnidirectional as possible for our bat tracking arrays and have only ever managed it using multiple microphones on a single head and mixing the outputs, and this results in some really horrible phase responses which seriously affects the frequency response. I'd be interested to know how they did it.

Have been finalising the dates for BCT Training courses. I will now be running the "Bat Ecology and Conservation" course at Juniper Hall, Surrey on the 16th April and Clumber Park, Nottinghamshire on the 16th July as well as the "Bat Detectors and Sound Analysis Level 2" course in London on the 9th May and Birmingham on the 22nd August. I will also be co-tutoring the two day "Surveying Bats" course at Clumber Park on the 3rd and 4th September.

Was very kindly sent the latest version of Batsound by Lars Pettersson. This is now version 4.1.4 and has a number of added useful features. The first is that you can now play back sounds at reduced speed without having to fiddle about with the time expansion factor. This used to be a real pain if you had recorded something on a D1000x at 500 kHz and then wanted to listen to it at 10x time expansion as you had to put in a time expansion factor of 500/44.1 = 11.34. The second is that you can now export graphic images in a variety of formats icluding windows metafiles, jpeg and png. This is a big improvment as the bitmap images in the previous versions were HUGE when imported into powerpoint. From my point of view, the best new feature however is that you can now more easily extract GPS information from files recorded from a D1000x or D500x with an attached GPS unit This makes import into Google Earth or GIS software a whole lot easier as you can extract all the GPS information from a whole folder into a spreadsheet. Nice

Wildlife Acoustics have launched the new SM2BAT+ ultrasonic monitor. Superficially similar to it's predecessor, this new incarnation can now natively record in zero crossing mode as well as full spectrum. This is now implemented in hardware rather than the cumbersome software conversion previously. This should improve sensitivity as there were reports of the conversion of full spectrum to zero crossing losing a lot of weaker calls. The file format is now standard .wav format rather than the in-house .wac format which took an age to convert from. It will be interesing to see if Anabat comes back with anything in return now that PDAs are getting harder to source as they're being replaced by smartphones.