As many of you may know, camera traps are triggered by a combination of heat and movement. They require these two variables to be present at the same time to work properly, so if something that is warmer than the ambient temperature moves passed the camera then bam – you get your capture.
But what about animals that aren’t warmer than the environmental temperature? Cold-blooded animals like reptiles that certainly move quick enough for the camera trap to detect them, but are not warm enough for the camera to trigger. Well, that’s straightforward to solve using natural or artificial basking sites and making use of time lapse features.
But what about animals that aren’t much warmer than the outdoor temperature and don’t move fast enough to be picked up either??
That was the problem we faced when Dr Becky Cliffe from The Sloth Conservation Foundation (SloCo) got in touch with her sloth conundrum.
Sloths are notorious for being incredibly slow creatures (this is actually a very clever adaptation as their small, slow movements go undetected by predators such as big cats and also conserves energy) but they also have very low body temperatures that often match that of the environment.
Couple that with the issue’s camera traps can face in rainforest climates (camera traps are weatherproof, not waterproof, and can sometimes struggle with humidity and monsoons etc.) – it was proving near impossible for Becky and her team to monitor and evaluate the success of the conservation work being done to help the sloths.
Part of the incredible work SloCo carries out is the installation of sloth canopy bridges – these rope-like bridges are set-up to enable safe passage and continued connectivity between their ever decreasing and fragmented habitat in semi-urban areas.
With the loss of more and more trees, without the canopy bridges sloths have no choice but to make the journey between their little bits of habitat across busy urban roads. Slow sloths and fast cars are making for a devastating combination with daily sloth fatalities. If that wasn’t sad enough, being forced to move along the ground rather than from tree to tree – the sloths are left exposed with no chance of a quick escape and are often subjected to attacks by feral dogs.
The success of the canopy bridges is therefore incredibly important for sloth conservation – but previous attempts to try and monitor their use and success has been difficult when the camera traps they’ve used have struggled to even notice the sloths.
So what could we do?
We met with Dr. Becky Cliffe to discuss what she’s already tried and the problems she faces and came up with a couple of ideas that may help with more successful sloth bridge monitoring!
Although all camera traps are fundamentally the same, the qualities of each can be dramatically different as each manufacturer tend to focus on a specific design feature – such getting the highest quality videos or speediest trigger. Each project is very different too and will need one feature primarily over any others.
For SloCo, they just need to know if the sloths are using the bridges and so the aim was ensuring getting reliable records of sloths and not missing any, rather than obtaining prize winning imagery. For this reason, we gave SloCo two different camera models to go back with and try out – each bringing to the table features that we thought would work best.
The first was a SpyPoint Force Dark. This seemed to us the most obvious camera to trial as it is one of the most sensitive cameras on the market with an incredibly fast trigger speed (0.07 seconds for photos and 0.5 seconds for videos). They also have the best battery life of all the cameras out there out the moment, so ideal to be able to use and leave at rope bridges for a long time. The downside of these cameras is that the quality of photos and videos are pretty standard compared to others, so for that reason we also gave them one of our most popular cameras to try out; the Browning Recon Force Advantage.
This is currently our favourite trail camera and the one we use in almost all our current projects. Really easy to use, the photo and video quality are also excellent and with a trigger speed of 0.4 seconds it’s super quick. The other major advantage of this camera is that we know it holds up well in rainforest environments having worked with other researchers and NGOs in the tropics.
We also gave a few pointers about camera set ups to get the best chances of capturing all the slow sloth action; such as good positioning being key to give the sensors the best chance of picking up the sloths’ reliably. We also gave some pointers on what settings would be most appropriate, e.g. using multi-shot photo mode on the Browning camera as it gives a photo sequence 2 seconds apart, giving the sloth more time to move in to frame.
But… have they worked??
So far, the cameras have been tested out in the sloth orphanage with the initial results being very promising and picking up the sloths! The cameras have now been installed on the rope bridges and we have everything crossed they work well and help SloCo understand more about how well their bridges are working to help these slow sloths.
You can head to The Sloth Conservation Foundation website to find out more about the amazing work they do, and for their take on the camera traps and sneeky sloth problem!