09 March 2014

Golden Mole Goodness

Long time readers will know this area as the Woody Cape. In 2012, while helping with the construction I took the opportunity to do a lot of camera trapping in the area. During last year's December holiday I decided to take some camera traps with me again.

I noticed some small mole hills popping up on the new "lawn" and thought that this is the perfect time to try out some subterranean (aka underground) camera trapping.

Scout keeping me company while I clear a hole for the camera trap

I've been toying around with the idea of camera trapping moles for a while, but when I saw Codger's underground adventures I knew I had to give it a try myself.

It was December holiday and I had a camera trap, time and an eager mole at hand. What more can you ask for?

I identified a recently pushed up mole heap and then started to dig it open. I found using my hands worked best, since it was easier to follow the tunnel by touch. Once I reached the main horizontal tunnel I started to clear some space for the camera trap.

I placed the camera trap on the opposite end of the hole as the tunnel

From previous experience with camera trapping small mammals at close range I knew that the video mode works best. At this close range the focus will be slightly blurry, but the animal will be close enough to the camera to compensate somewhat for the blurry images.

I placed my trusty Bushnell Trophy Cam at the far end of the hole and used an old tile to cover the hole. I then covered everything with a layer of soil. And waited...

Video: First signs of life...

My first glimpse of the little fellow was of it kicking some dirt towards the camera. I was frilled! I decided to improve my setup a bit and cleared a larger section of the tunnel.

Over time I was rewarded with one amazing video clip of a Hottentot Golden Mole.

Most Golden Moles have a "metallic" shine to their fur, which you can see reflecting the flash from the camera trap. Golden Moles are eyeless and have no external ears, nor tail. The tips of their snouts are covered by hard skin which, combined with their powerful front claws and webbed hind feet, makes for impressive digging tools.

Video: Hottentot golden mole (Hottentot Gouemol - Amblysomus hottentotus) underground

Getting any footage of these little critters were trickier than one would expect. Firstly, and to my surprise, I got a lot of false triggers. (I'm pretty sure the false triggers weren't super fast moles zipping past.)

At first I had the camera's sensor turned to high sensitivity, but that just filled the SD card with continues false triggers. The camera worked best at the normal sensitivity setting, which resulted in a manageable amount of false triggers.

I think some of the false triggers might by caused by bugs crawling around in the tunnel and over the sensor. I also suspect that the tunnel has some sort of ventilation system which might cause hot air to move around in the hole. The sun baking on the top of the tile covering the hole also can't help the situation much.

Another thing that surprised me was how often the camera would not pick up the mole at all, or trigger very late.

Video: Investigating the camera trap

On numerous occasions I would lift the tile from the top of the hole to find the tunnel filled with loose soil. Expecting great results I would start working my way through the video clips, just to find absolutely no sign of any Golden Mole. Amongst the false triggers I would notice only a sudden appearance of a huge pile of loose soil. Somehow the mole managed to fill an entire tunnel in front of the camera without it triggering even once. My guess is that this is due to either the mole being hidden behind the dirt which it is shovelling, or since Golden Moles are known to enter torpor, maybe they can somehow regulate their body temperature to such an extent that the camera does not distinguish them reliably from the hot air and soil in the tunnel.

It is difficult to make out what is going on in the still photographs, video seems to work better

I felt bad tormenting the little critter by always clearing open the tunnel. Every time I clear it, the Golden Mole would faithfully fill it up with soil again. It clearly doesn't like people messing with it's tunnels. Once it has decided where a tunnel should or should not be it sticks to the decision.

Digging through and moving soil around must be very energy intensive for such a small creature. They are only about 12cm long, weighing about 60g. After a few days of torturing the tiny animal by undoing it's hard work, the little critter decided to send me a message. When I lifted the top of the hole I found the front half of the hole, not just the tunnel, filled with soil. (Again with absolutely no footage of the little fellow actually doing it...)

The camera's view before...

The camera's view after...

To my mind this is an incredible amount of soil to be moved to seal off a tunnel, but I guess if the tunnel won't stay sealed then this persistent little digger won't give up either. Adding this to the heaps of soil I've cleared away earlier I felt to guilty to continue with the camera trapping and removed the camera. I'm sure if Golden Moles can feel satisfied then this little fellow must have done so.

Now, according to the literature I have nothing to feel bad about. These Hottentot Golden Moles are said to by able to dig 4-12m of tunnels per day. This heap might just be the result of a morning's work.

Fast forward two and a half months later and I find myself with some of my camera traps at home for some TLC and a blog post about a Golden Mole in the pipeline.

Now, I already know I have some Cape Golden Moles living in my yard in Cape Town. So I thought I'd try the same trick here at home.

Camera trap setup in my front yard

One particular section of my front yard regularly shows signs of Golden Mole activity, but to be honest I've found their tunnels almost everywhere in my yard. The surface tunnels are less noticeable during the dry summer months, but I assumed they must still be active. I searched for an old surface tunnel and started to open it up, like I did with the Hottentot Golden Mole's tunnel. Sure enough, I soon found a more permanent tunnel deeper down. I used some old roof tiles to cover the hole and placed the camera trap inside.

At first I tried the high sensitivity option again, but again I got lots of false triggers. I selected the normal sensitivity option and tried again. This hole doesn't get as much direct sunlight as the previous one and it was covered by much more soil and old twigs, so I guess the false triggers must be from the mole's built in air-conditioning or bugs.

Video: Cape Golden Mole (Kaapse Gouemol - Chrysochloris asiatica) underground

I've encountered this little gem before. Have a look at my old post over here.

The white marks where the eyes should be easily distinguishes this Cape Golden Mole from the Hottentot Golden Mole found earlier, 750km away, in the Eastern Cape.

Unfortunately not much is known about Golden Moles in general. You'll only find these amazing little creatures in Africa (most of which only live in southern Africa), so don't confuse them with European or American Moles. They are also not even closely related to Mole Rats.

Golden Moles are great in gardens and don't disturb the plants too much, especially if you give them time to establish some permanent tunnels. They eat insects and similar small critters and are in fact a huge benefit to have in your garden. They will consume a vast amount of pesky insects, free of charge, year round. If I have one complaint then it is that my local Golden Moles don't seem to have developed a taste for snails, yet...

Above ground view of the Golden Mole's home in my front yard


  1. Congratulations, and what an achievement! Never thought I'd see subterranean footage of golden moles, but there it is. Wonderful! Did you use a filter to dim the IR array? The lighting is pretty good for close range. I wonder if a piece of non-reflective glass would cure them of plugging up the open space? Kind of like a kid's ant colony between two panes of glass. It would be fun to try a fiberoptic camera in those tunnels. Many years ago, Oxford Scientific Films made some clips of moles coming down the tunnel and the camera lens was moving back as the mole moved forward. Amazing stuff. Since then, a similar short clip appeared on the internet -- done by a clever photographer.

  2. Thanks Codger :D
    I'm also frilled by the results and possibilities.

    Yes, these days I almost always use a piece of textured glass over the flash, especially at close range. I also dimmed the flash a bit more by putting some tape over some of the LEDs.
    I think one can improve the results with some fine-tuning, but I was happy enough with the initial results.
    See http://cameratrap.mywild.co.za/2012/10/on-move.html

    Next up I have to find a location and technique for the huge Cape Mole Rats ;) (Unlike the small Golden Moles I'm a little concerned that the Mole Rats might not think kindly of the camera trap and decide to carry it off... They are much larger than a Bushnell.)

  3. Yes - terrific work Henry. Such a great glimpse into their real lives and behavior. Wonder if any other species use their tunnels?

  4. Thanks guys, it means a lot :)

    @RandomTruth: From what I've read Golden Moles are very territorial towards other Golden Mole species, but will share a burrow system with Mole Rats.
    I'm also curious about other species using the tunnels, but (based on my small sample size) it seems like the Golden Moles are fast and serious about closing off damaged tunnels. Thus making it tricky to get camera trap results over a longer period of time.

    Also I've only tried photographing them a few times so I'm definitely no expert, there is still much to learn :)