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.
Pat Waring’s set up
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.
eBay IR LED Illuminator set up
Video IR setup from the back
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)
Maglite XL50 LED Torch
Pro’s: Small, light, good light output.
Cons: Care needed to prevent accidentally turning it on when not it use.
LED torches offer two advantages for bat workers; one is improved battery life and the other is next to no heat emission. The Maglite XL50 runs on three AAA batteries and has three light settings cycleable via the push button switch at the back of the torch: high, low and strobe. High offers 104 lumens and a battery burn time of 8h45m; low reduces output to 25% giving a battery life of 36h. On low setting the torch offers plenty of focussed light to check all but the deepest crevices.
The torch is small and light enough to carry day to day although it’s easy for the rear mounted push button to get knocked when in pockets resulting in unecessary battery drain.
The XL50 is a great little survey torch.
Hope R4 headlamp – £225 (at time of press)
Pro’s: Very versatile with multiple light levels. Great flood light in larger caverns Good battery life at lower light settings
Cons: Needs second battery for extended trips underground. Overpowered for day to day surveying.
Hope R4 headtorch
As part of the East Lancashire Bat Group project “Bats Underground” we’ve been undertaking swarming and hibernation surveys of Rossendale flagstone quarry tunnels where I found the light of my Petzl Spelios a bit underpowered in the larger caverns. This is where the Hope R4 headtorch came in.
The 4 x Cree XPG head unit
The Hope R4 is designed primarily as a bike light but comes as standard with a headtorch adaptor to allow it’s use as a “multisport” light. With 4 Cree XPG LED’s sequenced through the top mounted button to offer 6 levels of light including a maximum of 1000 lumens this is a serious bit of kit. In truth it’s probably too much even at it’s lowest level for day to day bat surveying, but for large systems it’s superb. The 2600mah li-ion battery offers burn times ranging from 1.15hours on high to 8.00 hours on low, I’ve alsways found the medium light setting to give plenty of light to navigate quarry tunnels while still offering circa 4 hours of light. A larger 5200mah battery option is available.
- Light Source: 4 x Cree XPG, R5 Bin
- Light Output: 1000 measured lumens, 1446 generated lumens
- Beam: Diffused uniform beam (+/- 12.5°)
- Distance: 105m
- Battery: 7.4v Li-Ion, 2600mAh
- Charge time: 3 Hours
- Weight: 235g (std), 338g (epic), 367g (endurance)
- Power levels: 6 (two sequences of three), including flash
- Burn time: 1:15 hrs – 8:00 hrs
Petzl Spelios Helmet/Headlamp
Pro’s: Great lighting in confined spaces, uses common AA battery, good burn time on LED
Cons: Feels underpowered in larger caverns and tunnels.
The Petzl Spelios is the industry standard for caving helmet/headlight combo’s and for good reason. If you’re considering venturing underground to carry out hibernation surveys or carry out cave research then this is the helmet you need to consider as a starting point.
Spelios showing Duo 14
The lighting element of the Spelios is delivered via an integral Duo 14 LED headtorch which features a switched halogen / LED light. In confined spaces such as small caves and roofspaces the 14 LED array should deliver as much light as is needed but the flood style spread will suffer in larger systems. The Halogen can be focused to an extent but it’s rare that I find a use for it and it obviously has an impact on battery life compared to the LEDS.
Spelios battery pack
The rear mounted battery pack balances the helmet nicely in use and houses 4 AA batteries. A rechargeable unit is available as an extra purchase but I find it’s just as easy to carry spare rechargeable batteries with you.
The helmet is available in two sizes covering head circumferences of 48-56 cm and 53-61 cm.
- Beam pattern : wide or focused
- Max. light quantity : 67 lumens
- Max. lighting distance : 100 m
- Max. battery life : 183 h
- Constant lighting : yes
- Operates on four AA / LR6 batteries or ACCU DUO (not included)
- Battery compatibility: alcalines, lithium, rechargeables ni-mh, rechargeables ni-cd
- Watertightness : IP X8 (waterproof down to -5 meters)
- Spare halogen bulb included
- Certification(s) : CE EN 12492, UIAA
- Weight : 505 g
Alpkit Gamma Headtorch – £15 (at time of press)
Pro’s: Cheap, great varied light options.
Cons: Sells out quick.
I’m a big fan of Petzl headtorches and have been for years but the Alpkit Gamma is a fantastic bit of kit, suitable for every bat worker and you can get three for the price of one Petzl. A bargain.
Gamma close up
The main XPC Cree LED throws enough light for navigating to survey sites, and has two switchable levels should you need to extend battery life. Once on site and for areas where you want minimum light spillage/disturbance a long hold down of the top button switches to cycle through the three smaller 5mm leds which offer white, green or red light. All three settings should offer enough light for tuning detectors, etc.
Battery life is good, it runs on three AAA batteries and even comes supplied with Duracell as standard. If you’re working on dimly lit road transects the rear battery case has a seperately switched flashing/constant red light which aids visibility.
A great addition to any survey kit bag and well worth getting as a back up for underground too.
- 1 x XPC Cree LED (up to 88 lumens)
- 3 x 5mm LED’s Red, White, Green (1.8 lumens)
- Weight: 118g with batteries
- Batteries: 3 x 1.5V AAA alkaline (included)
- Water resistant: tested to IPX4
Lascar USB2 temperature and Humidity Datalogger – £49.95 (at time of press)
Pro’s: Small, cheap and easily programmable.
Cons: Batteries need ordering (ebay is your friend here)
Lascar USB2 Datalogger
The Lascar USB2 datalogger is small, cheap and a very unobtrusive datalogger that’s perfect for recording conditions in bat roosts and hibernation sites. This datalogger is very suitable for monitoring crevices due to it’s size.
Lascar USB2 monitoring Temp/Rh in crevices used by Natterer's bats
Very easy to program with the supplied EasyLog USB software I tend to set them up to monitor at half hour intervals which means the battery lasts one year even in sub zero temperatures experienced during winter in exposed sites. Shorter intervals are possible but this obviously affects battery life.
With a netbook and a pocket of spare 1/2AA lithium batteries you can download and reset dataloggers in the field with ease.
Data downloads can be viewed either within EasyLog or imported into excel or similar spreadsheet programs.