06 May 2017

Slimy Surprises

I have been fortunate enough to enjoy some holiday time at the coast in the Eastern Cape. One of the things I wanted to make time for on my trip was to visit the rock pools during low tide.

A Triton snail (maybe Ranella Australasia gemmifera) at the Woody Cape

My exploration started off with a bang! One of the very first creatures I saw was this amazing Four-Tone Nudibranch.

Four-Tone Nudibranch (Godiva quadricolor) gliding along the edge of a small rock pool

From what I understand the nudibranch is basically a kind of predatory sea slug-like animal. It feeds on sea anemones and other nudibranch-like animals.

This encounter inspired me to try and return to the rocks at low tide on subsequent days in search of more interesting sea slug-like-things.

Blue-Speckled Dorid (Dendrodoris caesia) hiding under a rock
I turned over many rocks in search of interesting creatures. At first I didn't notice the Blue-Speckled Dorid under the rock, but when I dropped it back into the water it magically transformed.

The Blue-Speckled Dorid unfolded in the water

The little dorid feeds on sponges. I believe the fluffy bits at the rear of the animal is are the external gills.

Another, even smaller, sponge feeder is the Lemon Pleurobranch.

Lemon Pleurobranch (Berthellina granulate) hiding under a boulder

The animal below might seem artificially similar to the sea slug-like animals above, but this beautiful little critter below is actually a tipe of Flatworm.

A species of Carpet Flatworm (Thysanozoon sp.) found along the intertidal shoreline at Cannon Rocks

I was fortunate enough to be able to view one of these flatworms under a field microscope on a recent visit to De Hoop and my breath was taken away by just how beautiful they are.

I found another tipe of flatworm on the rocks, but this one looked a bit like a living blob of slime...

Gilchrist's Booger ergmm I mean Gilchrist's Flatworm (Planocera gilchristi) under a boulder

The Gilchrist's Flatworm feeds on tiny animals found in the tidal pools, such as worms and crustaceans.

Video: Flatworms moving about at Cannon Rocks

My attempt at filming a flatworm swimming failed, but trust me that it is something to behold. Luckily there is always next time. I'm already looking forward to visit the rock pools again and again, in the years to come.

Turban Shell (Turbo cidaris) heading back to the water

There is still plenty more to share from the Cannon Rocks coastline, even some camera trapping, so stay tuned.

08 April 2017

The Goose Mysteries

Back in November I placed my old Cuddeback camera trap amongst some boulders at Paarl Mountain Nature Reserve.

Camera trap at Paarl Mountain Nature Reserve

When I first came across the boulders it really struck me as an atmospheric place. Naturally I wanted to see what animals visited this place.

Common Duiker (Duiker - Sylvicapra grimmia) checking out the camera trap

It turns out that boulders can be tricky places to camera trap.

It is hard to find a good spot that does the landscape justice. Then the next problem is that the animals can come from any direction, because there isn't really a clear path in and out of the boulders.

As a result I got rather few photographs at this location. There was however two photographs that made it worth the effort.

Large Grey Mongoose (Grootgrysmuishond - Herpestes ichneumon) sneaking past the camera trap

The Large Grey Mongoose visited the boulders at 10:31 am. I don't camera trap these guys often, so it is always a pleasant surprise when one shows up. It is also a valuable addition to the reserve's species list. I saw one in person a few weeks before this photograph was taken, but having a camera trap photo is much beter for record keeping.

Precisely 24 hours later, on the dot, I got another unexpected photograph.

Spur-Winged Goose (Wildemakou - Plectropterus gambensis) mother with chicks well in line

Those chicks look awfully young to me. They must have recently hatched, very close by. This makes me wonder about two things.

Firstly, was the mongoose in the area because it knew the chicks where busy hatching?

Secondly, what are they doing so far away from water? These boulders are almost 1.5 km away from the nearest farm dam, and even further from the larger catchment dams. I did some reading and apparently the Spur-Winged Goose is know to breed up to 1 km away from water, so 1.5 km sounds plausible.

They will have a long walk down to the water and some might not make it if that mongoose is still in the area.

18 March 2017

Rolling With The Golden Mole

I'm still busy forming my opinion about my new SecaCam HomeVista camera trap. I believe in finding the strengths and weaknesses of each camera trap I own. For the HomeVista the wide field of view and dynamically adjusting flash intensity sets it apart from other camera traps.

This is the first camera trap I've seen that is capable of adjusting the intensity of the flash based on the distance between the camera and the animal. This helps to reduce the amount of overexposure in the photographs.

The following sequence of a Porcupine family at Paarl Mountain illustrates the dynamically adjusting flash very well.

Porcupine (Ystervark - Hystrix africaeaustralis) with full flash - showing the bushes in the background

Porcupine with medium flash - note that the bushes are no longer visible

Porcupine with low flash - notice that the Porcupine in the background is barely visible

The combination of the wide field of view and the dynamically adjusting flash felt like the perfect combination to test on my resident Golden Mole.

Cape Golden Mole (Kaapse Gouemol - Chrysochloris asiatica) showing his shovel like hindfeet

I usually have to physically dim the IR flash and set the camera trap to use the lowest flash setting available, but with the HomeVista I didn't need to change anything. It works great in a confined space.

I find that videos usually work best when dealing with very small mammals, but I wanted to test both the photo and video settings. I had the camera trap take 5 photos and then a short video clip, but I think only 1 photo and then a video would have been be better.

The video clip below turned out rather comical, albeit a little bit distressing to watch.

Video: Cape Golden Mole slipping and rolling down a slope

I'm also trying out new ways of creating the holes I use when camera trapping underground. I want to make the holes a bit larger and more sturdy so that they will last for longer. I'm now covering the hole with wooden planks, for easier access to the camera trap. The wooden poles, which are used to support the planks, can be seen in the video.

This hole is fairly deep, much deeper than my previous attempts, and as a result the tiny Golden Mole struggled a bit to climb up the slope. The bottom half of the soil is rather hard, so the subterranean traveler wanted to get back to the softer top soil. Once he makes it to the top you can see him quickly tunneling away.

Golden Moles are completely blind with no external eyes at all (their eyes are non-functional and covered by skin and fur). It really is a marvel that the critter is still clearly able to know where it is and where it wants to be going.

It has been hot and windy here in Cape Town and I've been having trouble using this camera trap in more conventional locations. It seems to trigger very easily from warm wind and vegetation.

Luckily it seems to work well for Golden Moles and I'm excited to try this camera trap out in more areas where very small mammals might be scurrying around.