11 November 2010

Keeping Company With A Shrew

Two rodent species shared the runway with the shrew. The Four-Striped Grass Mouse (Streepmuis - Rhabdomys pumilio) showed itself only during the day.

Video: An adult Four-Striped Grass Mouse made a short visit

The adult mouse made an appearance twice, but a baby mouse also showed up on two separate occasions.

Video: The baby mouse is much smaller when compared to the adult in the above video

Mouse numbers seem to have dropped after much of the grassy slopes were burnt at the end of summer. The new grass that sprouted during the wet winter months are now bearing seed and I'm starting to notice more mice again, especially youngsters like this one.

Video: Youngster hopping along

Not surprisingly the other, and most frequent, user of the runway is our old friend the Vlei Rat. The Vlei Rat seems to be, for the most part, the creator and maintainer of this runway.

Video: Mr Vlei Rat gracing us with his presence

There are a bunch of different Vlei Rat species that look all very similar, but I'm reasonably sure this is the classic Vlei Rat (Vleirot - Otomys irroratus).

Video: It is tricky to place the camera so close to the trail and still get the camera's sensor to trigger in the desired area - the distance between the lens and the sensor becomes a factor...

The interesting thing about the Vlei Rat is that, like the shrew, it is active both during the day and at night.

Video: He is clearly awake and not merely sleep walking


Those of you wondering just what exactly a "vlei" is can check out these links over here and over here. I don't think the word is as common as another Afrikaans word "veld" that is found more frequently in English (over here and over here).

While I'm at it I might even explain where the "berg" part of Tygerberg comes from over here (it means "mountain, etc.").

The Tyger part is a bit older and more confusing. Some of the early settlers sometimes referred to Leopards as Tygers/Tijger (or similar), which implies a tiger. Some where familiar with the true tiger and the word must have spred around and stuck. In modern Afrikaans a tiger is a Tier and the word Tyger is not used anymore. However many rural and older people still refer to a Leopard as a Tier (tiger) even though they know better. Since there are no real wild/native tigers in South Africa it doesn't result in any real misunderstandings or confusion. Further more, historically, a Tyger also reffered to a mythical creature and this might have been another factor in the confusing use of tyger/tijger/luiperd/etc. in historical times.

You can also check out my old blog post for some more info on how Tygerberg might have gotten its name as "Leopard-Mountain", though I have no doubt there were also plenty of Leopard on the hills in the old days, and not the tortoise variaty...

08 November 2010

Seeking The Shrew

I made a quick stop at Tygerberg to switch the SD card on the Bushnell. I was hoping for Shrews. I was very happy when I got home and checked the memory card.

I don't know what it is about these tiny mammals, but I really enjoy them and find them fascinating. I've been on the lookout for a good shrew spot for some time and tried one or two spots with no luck, but when I saw this location I knew I struck gold.

My Bushnell trail camera on the job

I got my angle slightly wrong, but I'll adjust that soon and move the camera back slightly. Still, I'm very pleased with the results.

 Video: Darting past the camera during the day

The shrew in question is the Reddish-Grey Musk Shrew (Rooigrysmuskusskeerbek - Crocidura cyanea).

Video: The shrew gave the camera only a short glimpse

This is not the first time I've photographed a Reddish-Grey Musk Shrew. I photographed one a couple of months ago at Kistenbosch.

Video: This time around a slows down a bit

Some people might confuse a shrew with a rodent, but they are in fact very different and belong to the Soricomorpha order.

Video: Finally some great action in front of the camera

The shrew shared the runway with a couple of rodents. I'll share some of their videos soon.

Video: The last video clip of the shrew before the memory card filled up

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.

04 November 2010

Puddle Of Dreams

Sometimes I find a location for a camera trap that really gets me excited, but then fails to deliver...

The puddle... (I don't know what the proper word/name for this sort of thing is)

I stumbled upon this little natural puddle. It forms in one of the small streams that runs down the hill towards the dam near the main entrance at Tygerberg. I think it makes a very pretty backdrop. I have camera trapped Water Mongoose and Cape Clawless Otter higher up on this stream. I even found some freshwater crabs living in the puddle.

This crab was walking along the bottom of the puddle

My hopes where running high. I decided to leave the Cuddeback behind to monitor the puddle. I knew that the Cuddeback wasn't the perfect camera for this sort of location. It has a very narrow detection zone, but compensates for it by having a fast trigger time. It works best when pointed across a trail. The factor that made me choose the Cuddeback was its natural/white flash. With the Moultrie out of action I only have one white flash camera. I was hoping for some awesome nighttime photos of otters, etc.

You might have noticed by now that none of my hopes or dreams materialized. But it was not a total loss. At least I got some photographs. Two birds a Helmeted Guineafowl and a Black Sparrowhawk (new).

Black Sparrowhawk (Swartsperwer - Accipiter melanoleucus) visiting the puddle

Yet, despite the bad luck with the Cuddeback a very observant reader might have noticed that the first photograph shows a Bushnell Trophy Cam pointing towards the puddle. Well, I'm just not ready to give up on the spot yet. I'm hoping the Bushnell's wider detection zone will stand a better chance recording the action that might, or might not, be happening at the puddle. Beggars can't be choosers and IR images will have to do :)

On a slightly different note: A few posts ago I mentioned having never seen a baby Leopard Tortoise at Tygerberg. Well, I stand corrected. This little fellow rocketed off into the roadside cover when I started pointing a huge lens in its face. I prefer not to interfere to much with the animals for the sake of a simple photograph and I almost never pickup tortoises. The result is that on a warm day these guys move quite fast and I only got a few shots at it before it was gone.

A baby Leopard Tortoise (Bergskilpad - Stigmochelys pardalis) at Tygerberg Nature Reserve in Cape Town
 
Bulldozing his way to peace and quiet

02 November 2010

Tunnel Travelers

It can be tricky to find a good location for a camera. Although I'm not much of an expert and most of what I know is self taught, I'll try and talk a bit about how I go about picking camera trap locations.

The most common area used to place a camera trap is a trail (natural or artificial). Trails can be anything from a gravel road used by vehicles, to a faint path going through the vegetation warn out by the repeated passing of animal feet. The thing to remember is that, in general, if the trail makes it easier for you to get around, then it will make it easier for the animals as well. Animals will tend to follow either the least difficult path or the most rewarding one to get from point A to B.

Caracal (Rooikat - Caracal caracal) using a tunnel to pass underneath a road that intersects the Tygerberg nature reserve

Another thing to look out for is evidence of recent animal activity on the path (such as scat, remains of a kill, tracks and disturbed vegetation). For the above photograph I found plenty of animal tracks in the dry mud inside the tunnel and also a lot of other signs of frequent traffic along the rest of the path.

A Leopard Tortoise (Bergskilpad - Stigmochelys pardalis) also uses the tunnel to get around

You can increase your odds of trapping an animal along these trails by looking for natural funnels and forks in the road. The tunnel is a perfect location because it forces the animals to pass through the small bottleneck to enable them to cross the road and enter the linked section of the reserve.

The Caracal didn't even seem to notice the camera thanks to the infrared flash

I had another camera about 200m down the trail and 1 hour and 43 minutes later the same Caracal walked past the second camera. The second camera was placed in an area where the trail runs close to the fence. The leave litter clearly indicate a well worn out path (mainly thanks to the vigilance of the Helmeted Guineafowls).

Helmeted Guineafowl (Tarentaal - Numida meleagris) eyeing the camera

Trails are by no means the only good places to find concentrated wildlife activity. There are many other "places of interest" that attract animals.