07 November 2010

Playing With The Cool Kids

Here in South Africa the cool thing to do with a camera trap is to photograph Leopards. Not only do their dazzling spots get the heart racing of many a nature lover, but it can also be used to identify individuals. This is a useful feature to get an estimate of Leopard density and population size in a study area.

The result is that because of the Leopard's fancy clothes, bad attitude and social status all the cool kids want to play with them (being the coolest cat om the block). This means that camera trapping over here is often skewed towards Leopards (and other medium to large mammals, especially of the predator variety, that happen to live in the same neighbourhood).

You might have noticed that I haven't posted any Leopard photographs on this blog. That is mostly due to the fact that there aren't any at Tygerberg and I haven't ever trapped one at any other location. Lastly, I never wanted to play with the cool kids at school, much preferring the company of the lesser mortals, so I might be subconsciously avoiding them on purpose...

Camera trapping (and this blog) is a hobby and not part of some research project, etc. It allows me the freedom to pursue my own interests.

Still, every now and again even the best of us stroll off the straight and narrow... What am I on about? Well, last week the Cuddeback (the camera trap of choice for Leopard research) photographed several Leopard Tortoises (Bergskilpad - Stigmochelys pardalis) at Tygerberg. So, I though I'll play the Leopard Research Project game. I will take this opportunity to explain how the cool kids do it... (Not being a cool kid myself, I might be a bit off target with regard to the finer details.)
Research tool of choice: The Cuddeback Capture

Firstly, you preferably need to get a clear photograph of your subject, from both sides. In order to do this the cool kids use two cameras, but because I don't have rich parents I only use one and hope for the best. Last week I was lucky and all the Leopard (Tortoises) walked past the camera in the same direction, freaky...

First up was Tortoise A

Why is the Cuddeback the camera of choice? Well, I think it is because it has a small detection zone and thus only trigger when the animal is in the middle of the frame. The Cuddeback also has a fast trigger speed which means that you can place it at about 90 degrees to the trail and it will be fast enough to snap the photo as the animal walks past the camera. This results in more photographs where the subject is in the centre of the frame and thus makes identification easier.

Tortoise B came by 30 minutes later

The thing about Leopard (Tortoises) are that they have unique spots. It is quite easy to compare the photographs and conclude that of the 7 photographs taken there were 4 Leopard (Tortoises) in a 3 day period that walked past the camera. This is usually done by identifying a few spots in a particular area that form an unique and easily identifiable pattern.

About 50 minutes later Tortoise B came by again

The most curious thing, for me, is that they all passed the camera in the same direction in a relatively short period of time. One individuals even passed by three times, each time going in the same direction.

Shortly afterwards a new guy appeared on the scene: Tortoise C

As with Leopards one can sometimes take a guess at the gender of the animal by the body shape. In this case males have a longer tail than females and a concavity underneath on their stomachs. I'm no expert with tortoises, so I'll rather not venture a guess...

The next day Tortoise A showed up again

These guys warm up well in the sun and move about easily on a nice sunny day. All the photographs were taken in the afternoon and evidently they warm up enough to trigger the heat sensor of the camera. On the last two days the tortoises seem to be more to the left of the image than on the first day, I'm thinking they might have been warmer on those days and moved about faster.

Tortoise A showed up on the last day again

I moved the camera on 5 November. The last Leopard (Tortoises) was photographed on 1 November. Afterwards I only photographed two suspicious looking people passing down the road... I'm glad I didn't loose the camera.

Tortoise D wrapping things up

After my time spent with the cool kids I'm looking forward to (hopefully) spend some time with a few shrews next week.


  1. Leopards are way cool, whether tortoise or cat. Since the tortoises were all travelling in the same direction, does that mean that they roam their territories in circles? Do they even maintain regular territories?

  2. The leopards seem to be winning all the races. Will the hare ever show?

  3. @John: The books say 18-360 ha homeranges, but the core ranges are much smaller. There can be anything from 2-85 tortoises per 100 ha. My general impression is that they just wonder around, and happen to stay in the same core area. (Captive animals have been known to perform long return journeys).

    @Codger: I've been wondering that myself. No bunnies at Tygerberg, yet... I'm hoping that they are around and that I'm just picking the wrong locations.