I was so impressed when I saw Pat Waring’s video presentation at the BCT northern bat workers conference I thought I’d build something similar. While Pat’s system from www.batmanagement.com was great it was also quite pricey and would involve importation from the states.
So I headed off the eBay.
I quick search of the term “IR LED Illuminator” brought up a fair array of choices, most of which were located in China or Hong Kong but given a max price of £10 for a 48 led 850nm unit I guessed it was worth a punt. Sit back for a few weeks until the units arrive and then a quick trip to Maplins for the necessary leads and fittings.
For just under £50 I managed to get a 4 x 48 IR LED Illuminator set up which runs off the same 7ah 12v battery I use through autumn to power remote Anabats monitoring swarming sites.
I’m using a Sony HDR SR5 video camera which has the all essential 0 lux nightshot setting and records direct to a 40gb hard drive (again an eBay purchase – £100 brand new unused).
Note the 850nm illuminators have a very dull red glow when on, but emerging Brown Long Eared bats haven’t been affected by them so I figure in a barn setting they’re unlikely to be a disturbance factor. Last night they managed to pick up non echolocating BLE’s light sampling in the apex of a barn roof it would have been easy to miss if you were relying just on detectors (I was using both Anabat and Pettersson 240x, Anabat missed them and the 240x only recorded very faint echolocations which couldn’t be seen in Batsound v4).
If you’re surveying sites such as barns likely to have Brown Long Eareds or Myotis sp can you afford not to use video to strengthen your survey methodology?
Here’s an example of the footage and detail you can capture (actual footage is fullHD out of the camera)