23 November 2010

Tricky Bits At Tygerberg

Camera trapping can be tricky during the best of times, but there are a few things that I really struggle with: dense vegetation and strong wind.

The western slope of Tygerberg Nature Reserve

More than half of Tygerberg is covered by very dens growing shrubs. Below is a map of Tygerberg that shows where I have camera trapped thus far (including a few general observations, mostly tortoises).

Map of Tygerberg and my camera trap spots

As you can see I'm clearly more active on the eastern slope. It's also worth mentioning that the main entrance to the reserve is on the eastern side as well.

I've been wanting to trap more on the western slope, but it can be a tough walk to get to the cameras and back. But mostly I find it very tricky to find a good spot in the dense vegetation.

An "average sample" of the western slope

One of the things I'm curious about is what animals actually move about in this sort of habitat? It is very difficult for me to move from point A to B without a path. Luckily if you look hard enough, every now and again, you might stumble across something that looks more promising for camera trapping: a small or faint trail.

Hidden amongst the shrubs there is a small path (this is one of the clearest I've found yet)

I'm trying to trap in areas that I have been avoiding up to now. I've been avoiding them because they look less promising and trickier to setup the cameras in. The path above looked good, so I placed a camera there after opening it up a bit more by cutting back a few twigs and clearing out the dead branches.

My next source of 700+ photos of moving vegetation in, I predict, 3.5 hours (sans-animal I'm sure)

Another problem is that I have only 3 camera. Two Bushnell Trophy Cams and one Cuddeback Capture. Both cameras models are great under the correct conditions that suit them best, but on the western slope both models have some limitations.

The Bushnells' detection zone is very wide. This week one of my cameras filled the SD card in the first 4 hours after I placed it thanks to the wind and the vegetation on the sides of the path, even after I thought I cleared everything that might lead to a large number of a false triggers. The worst part is that I only checked it a week later, so it was 6+ days lost. (The result of which is this blog post and you, poor readers, now have to suffer the consequences of my reckless, amateurish and irresponsible actions.)

The Cuddeback has the opposite problem. It has a very narrow detection zone and works best when positioned to look across the trail. Under the circumstances on the western slope it is difficult to find a good trail where the camera can be placed sufficiently far back to take decent pictures and still point across the trail. The Cuddeback has severe problems when monitoring an "area" such as a small pool. Even when 2 trails meet can get very tricky to place the camera for optimal coverage.

But, there is some good news also. I believe that it is thanks to these challenges and complications that most camera trappers do what they do and enjoy the good times so much more :)


  1. Would it help if you put some sort of tube. or open ended box in front of your Bushnells that would narrow the field of view to eliminate some of the waving vegetation? Have you tried to set up camera traps in other nature reserves in the Cape Town area?

  2. Yes - if it was easy, it wouldn't be nearly as fun or interesting.

    You gotta try that western slope though - trails and thick stuff. It's a whole different ecosystem and that can mean new species!

    Maybe you can try a set with the camera up a little higher, and pointing down toward the scene to reduce the false triggers from bad sun angles?


  3. Agree with RT. "Go West young man" -- and I'll get back to you soon about the analysis we were discussing.

  4. @John: That sounds like a good idea to try, thanks. Maybe I can put electric tape across the sides of the sensor to create a similar effect. I trapped a bit at Kirstenbosch on Table Mountain last year and I want to do a couple of months at Cape Flats when I have a camera or two available, but at the moment Tygerberg keeps me bussy.

    @RT and Codger: I agree the west is the best.

  5. I hadn't realised that Tygerberg was so closely hemmed in by heavily populated areas. I'm very impressed at the huge number of species you've been able to get there. Amateurish indeed!

  6. @Lynda:
    The northern section (not part of the reserve) of the Tygerberg hills open up to some farmland. I think it makes it easier for the animals to move around. Once the main (reserve's) hill gets completely encircled then I guess the Honey Badger, etc. will disappear.

    I'm also impressed with the variety I've photographed thus far. I set out hoping to get close to 20 species of mammal and I'm already on 23.

    One of the things that appealed to me concerning camera trapping at Tygerberg was that it is a small natural island/finger in the middle of the city. I wanted to know what animals still cling to an existence on the hills.