American-style bathouse

Having to potentially do a pipistrelle exclusion this summer, I thought I'd have a go at making and installing an American style bathouse on the building just to see if it worked. I used some modified plans from the Bat Conservation International (BCI) publication 'The bat house builder's handbook' to construct it. I had to adapt the plans slightly for the metric measurements so used a quarter sheet of 9mm ply and another of 12mm ply. I also used exterior grade plywood for the sides as this would make it more long-lasting I figured. This means you will need a little extra ply for this and luckily I had some scraps laying around. I also left out the ventilation holes as it's cooler in the UK, and added a bottom as well.

The total construction cost was around £70 but if you make them in bulk with four boxes to a full sheet of 9mm and 12mm ply, it should come down. I also added a roofing felt cap over the top to keep the rain off longer.

 

This is the ply all marked out ready for cutting.

This is the timber all cut out and ready for assembly.

The assembled and painted bat house with a 30cm ruler for scale.

View with the bottom door open at the four internal chambers.

Total construction time was about three hours, excluding painting.

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.

Batsound under WINE on Ubuntu 13.04

Well Ubuntu 13.04 'Raring Ringtail' is here, and it makes for an easy upgrade, even on a dual boot Windows 7 machine, my only gripe being that it overwrote my Windows 7 bootloader with Grub-2, the Ubuntu boot loader. Not a problem unless you decide to remove Linux in which case you won't be able to easily boot into Windows. Batsound still works well under WINE but I still haven't sorted out the graphics export problem. The dialogue appears but the resulting image files are corrupted. Not a huge problem since Ubuntu has such a versatile set of screen grabbing and editing tools. I tried out crossover which is a commercial version of WINE to install Batsound.  Again, this worked fine, and now in the export graphics image dialogue box the option to export to .jpg appears but the files are still empty or corrupted. As far as I can tell, all other functions like audio capture and playback work just fine under Ubuntu.

Still plugging away at Batsound on Linux

Not much closer to a solution for the saving of sonogram images from Batsound under Linux. It seems that WINE only has limited support fir JPEG, but then .png files would arguably be better for export anyway, preserving the crisp edges of text labels. It does look like there may be a way of configuring Widows drives under WINE, so that files would not have to be in the Linux partition. That's part of the fun of Linux, problem solving....

Batsound under Linux

After someone asked me about sound analysis tools under Linux at the BCT conference in York it's been on my mind. There is the excellent Audacity, but this has limited tools of interest to the bat surveyor, good though it is. I had an old and very unresponsive laptop that was struggling with Windows XP (20 minutes to boot-up - not good), so I put Linux on it, Ubuntu 12.10. The installation was not without issue, the wireless networking especially, but once it was on I had a working, fast laptop. Now for Batsound....

I was expecting a fight, but it was actually very straightforward. First from Ubuntu software center install WINE (Wine Is Not Emulator). Then right click on the Batsound.msi file. It actually says in the WINE documentation that it will not install from an .msi, but this was fine. This will install it to a virtual C drive which is actually hosted on your Linux home partition. Enter your name, organisation and the serial number and off it goes.

Batsound then appears in your list of applications (DASH in Ubuntu), click on it and it runs! Just as fast as normal. I'll report any issues I find but at the moment the only thing I have found not working is that it won't save the workspace as an image file. Also, you can't access your normal C:\ drive for files. There must be a workaround for this somehow.

Just for fun, I uploaded a few videos of some work I did at Manchster University where we put dead bats into a micro CAT scanner. Taking the 4000 or so x-ray images of the bat as it rotated in the chamber I stitched them together into a film. I hasten to add that the bats had all died from natural causes and had been in my freezer for years. In the first one, of a Daubenton's bat, you can see nice details of the skull, teeth, Cochlea and shoulder.

http://www.youtube.com/watch?v=JxIdHgAy-Yc&feature=g-crec-u

The second is of a long eared bat, you can see the ears as light shadows. Again, nice detail in the cochlea.


http://www.youtube.com/watch?v=VEiUoa6pERw&feature=g-crec-u

Whiskered bats

Still processing the photos from the Top Hill Low batbox check. We found a couple of whiskered bats, which were a challenge to photograph as they are notoriously wiggly and vicious, but I did get some pictures of the tragus and 'gentleman's part' which are identification features.

And those of a more delicate constitution, look away now...