06 July 2010

Many Marvalous Mice

I've been wanting to point a camera at some rodent burrows, but couldn't get myself to "sacrifice" my old Bushnell Trophy Cam until I got my new cameras last month. So, off I went in search of what I would consider a homely and camera trap friendly burrow. Not long after starting the search I found one.

Camera keeping the burrow under 24/7 surveillance

So who's burrow is this? As far as I can tell the owner is a Cape Gerbil. There where one (sometimes two) Cape Gerbils in 60% (30) of the video clips and were seen using the entrance frequently.

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Video: The Cape Gerbil (Kaapse Springmuis - Tatera afra) seemed interested in the sudden appearance of a strange object that glows red when he moves (the infrared flash glows red)

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Video: Cape Gerbil foraging around the burrow

So who else uses the burrow? The second most frequent visitor was a Four-Striped Grass Mouse. It seems to use the burrow as a quick escape from predators and was seen in 26% (13) of the video clips.

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Video: A Four-Striped Grass Mouse (Streepmuis - Rhabdomys pumilio) showing off some fancy footwork

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Video: A Four-Striped Grass Mouse having a snack and then relaxing in the morning sun

You might have noticed that the two main users of the burrow are active during different times of the day/night. However, there are some visitors that don't keep to such orderly arrangements. The Vlei Rat visited the area mostly at night, but also showed his face in the neighbourhood during the day and was present in 12% (6) of the videos.

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Video: Vlei Rat (Vleirot - Otomys irroratus) looking for a snack

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Video: Vlei Rat hogging the entrance

With all these rodents around, surely there has to be somebody willing to reduce their numbers? And indeed there are, many. I moved the camera to a different (close by) burrow and switched to photo-mode last week. A Caracal graced us with it's presence while looking for a mouthful-o-mice.

Caracal (Rooikat - Caracal caracal) checking out the burrow

Naturally death doesn't only come from the ground, but it can also come from the air. I was walking up a hill recently when a Rock Kestrel flew past me carrying a mouse it just caught. It landed on some concrete nearby to have a peaceful meal.

The Rock Kestrel (Kransvalk - Falco rupicolis) however managed to drop the mouse into the concrete-thing and spent a moment trying to fish it back out

Aha, got it back!

Learning from his mistake he decides to settle down on the edge to finish his meal

Much better!

Lastly, if you are interested in seeing some truly remarkable camera trap photos of a Dusky-footed Woodrat (from America) check out Randomtruth's blog entry over here.

5 comments:

  1. Very nice collection of rodent footage and their predators. It's good to see the little guys.

    Did you put a filter over the IR light for the night video?

    We've been experimenting with the Bushnell Trophy cams at Chimineas and have been pleased with the results. A piece of milk carton plastic made a suitable IR flash filter to reduce the brightness of close range pictures. Images are sharp and the unit is compact. We did get a lot of daylight false exposures however. Too bad it can't be set for night time pics only.

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  2. Hi Codger, thanks for the comment.

    Yes, I did reduce the IR flash, but clearly not quite enough. It's hard to estimate an effective amount on the spot and you can't really test it during the day to see whether it was enough or not.

    I never want to bring any camera home (for proper testing) because I always think “but what will I miss while the camera is at home”. So, I sort off end up testing thing in the field by trial and error. Its a bad way of doing it, I know...

    My Bushnell Trophy Cam 2009 definitely has a setting where you can specify the times when it should be active/inactive. I used a 7pm to 7am setting at the pond in February to avoid the Guinea Fowl during the day. I'm not too sure about the 2010 model, but I guess it should have a similar setting.

    Since I'm able to check up on the cameras every 1-2 weeks here at Tygerberg I tend to be less bothered about false triggers. With a 2+ GB card and not too much wind the SD card never fills up.

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  3. Have you tried aiming the camera at marking trees? Research shows that numerous mammal species will visit and "use" a single tree.

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  4. Henry, please send me email at chindwin@sbcglobal.net -- I have some questions about the Bushnell 2009 Trophy Cam. Many thanks.

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  5. @Buford: Unfortunately trees are somewhat hard to come by in this part of South Africa. There aren't really many proper trees in a usual (natural) Fynbos landscape and Tygerberg is no exception. It has a few “big shrubs” that could be called trees, an there are one or two sections with “real” trees growing next to a little stream, but the majority of the habitat at Tygerberg is either shrubby-grass, grassy-shrub or just plain dense shrubs.
    That is part of the reason why huge areas of Table Mountain (and Tygerberg) was once covered in pine plantations (and many parts still are, although not really on a “commercial scale” anymore).

    @Codger: Will do.

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