Quick guide to choosing and deploying trail cameras to good effect. Small all-in-one digital trail cameras are now used worldwide to monitor the lives of some of our more elusive and noctural creatures. Follow @animalsocieties
All-in-one Trail Cameras
Small all-in-one digital trail cameras are now used worldwide to monitor the lives of some of our more elusive and noctural creatures. With their small size and weight, long battery life and ability to shoot video, stills or timelapse, these units have become a go-to device for conservation expeditions and projects across the globe. Many projects have deployed large arrays of traps and some are now using citizen science to crack the problem of processing the vast amount of imagery that they produce. Check out Serengeti Snapshot, WildCamGorongosa & ChimpAndSee – and why not help them ID a few mammals while you’re there!
These traps are also a great addition to any trip in to the wild. We often take a couple with us to keep tabs on promising sites. I really like the Bushnell HD units, but there are plenty of makes to choose from. I have found TrailCamPro a handy resource for the latest reviews and comparisons. The strength of these units is their ease of deployment, but a little bit of know-how can really help, so I thought I'd share a few tips and tricks...
Choosing your traps…
Trap quality versus trap number: its worth thinking about the features that you really need, as your overall success may be governed more by the number of traps that you deploy than the quality of each one. So you may get better results by compromising on luxury features if it allows you to buy more traps. It doesn't matter how good your trap is if nothing passes by!
Look for a unit with a short trigger lag: long trigger lags may leave you consistently missing your subject as it has moved out of shot before the image or video is captured (though careful placement can minimise this risk). As models vary greatly in their trigger lags, its worth considering this. Many traps also take much longer to trigger videos than stills, to the point where some projects monitor key sites with two units - one for video and another for stills. It is also worth checking the minimum trigger interval (the time between successive shots), if you're shooting stills.
Think about the lighting that your trap will produce: often we're particularly interested in capturing nocturnal creatures, in which case its worth thinking about how your trap will light the scene.
The cheapest units may take still images using a visible-light flash; this can make your camera very conspicuous at night, may preclude nocturnal videoing, and may greatly increase the trigger interval. You get what you pay for.
Most mid-range units instead use a panel of near-infra-red LEDs to light the scene, allowing for more subtle lighting, the capture of nocturnal video and shorter trigger intervals. The red glow that they emit is still typically visible to the eye though, and so someone passing your trap at night may well notice it, increasing the risk of theft. Many animals can also see this light, which can yield fun videos of carnivores poking at the peculiar light-source, but can also sometimes spook skittish animals.
Higher-cost units may use 'no-glow' or 'black-light' LEDs that emit no light visible to the human eye, making them much more cryptic at night. This can be useful, but they're expensive - and of course they're just as visible to thieves in daylight!
SD cards: there is no need to buy expensive cards with super-high transfer speeds. If you're at all unsure, just check the required transfer speed with your trap's manufacturer.
Placing your traps...
Think like your target animal: game trails, mineral licks, fruiting trees, river crossing points, tunnels, aerial highways, water and wallows can all be great places to place traps if they show signs of use or are rare resources in your animal's environment. Though less photogenic, rubbish pits or bins are often a great place to pick up scavengers - this yielded my first striped hyena!
If placing the trap on a trail, try facing it at 45 degrees to the trail, rather than directly across it. Then you’ll catch your animal on its approach, giving the camera time to start recording, but you should also get a side view which can help with identification.
Think about the sun's trajectory over the course of the day: try to avoid pointing your trap in a direction that is likely to present challenging lighting conditions (e.g. sun within the frame).
Think about what may grow near, on or in your trap: to avoid your trap being triggered by vegetation (particularly when the wind picks up), think about what is currently there and what may grow in to that space before you return. On many traps you can also set the sensor's sensitivity so as to minimise false-triggers from vegetation; its worth weighing the benefits of doing so against the associated risk of missing the movements of smaller animals. If your trap has any ports for cables etc, I'd also ensure they're closed - slugs, termites & potter wasps will all love to set up home in your trap! Finally, if you're working long-term in humid areas, I'd place silica gel packs inside your traps and seal the trap as well as you can; long-term exposure to moisture is a major cause of trailcam mortality!
Consider setting the intensity of the trap's integral lighting: some traps allow you to set the LED brightness, to cope with variation between sites in the expected proximity of your subjects. For example, if its set too high, the monitored area close to the trap may be overexposed, hampering identification.
Consider video: when working with many traps or in remote areas it can be worth shooting stills; your cards will take longer to fill and your batteries may last for longer. But if not, consider video. The movement and sound can really help identification, particularly at night, and often reveal interesting behaviour. For research projects the videos are great for attracting media interest too. Be aware though that video trigger times can be quite a bit longer than still trigger times - check your trap's specs.
Attachment: traps are usually shipped with a strap for fixing them to a tree. But that tree is rarely where you need it, and the straps rarely leave the trap firmly in place at exactly the angle you'd like. So give yourself more options with mini tripods, tree brackets (great for fallen logs etc) and foam pipe-insulation (for securing to skinny trees) - and you can never beat a pile of cable ties! Oh, and if you're around hyenas, bears, elephants or inquisitive primates, you might want to invest in an iron box and some bolts!
Think about labelling your trap (in the local language!): a small label explaining why the trap is there may be enough to make a light-fingered passer-by leave it where it is!
I now use trail cameras most when looking for promising sites in which to place SLR camera traps.
So if you're interested in camera trapping from a photography perspective, you might enjoy this...
Because if you used this...
...you might get this...