28 August 2012

From Out Of The Blue... Eh Black

I've always wanted to get images of bats on my camera traps. I assumed that it will require lots of hard work setting up various camera traps that specifically target bats. The dream was to, one day, get at least one semi-decent photograph of a bat flying past the camera. (I still hope to one day stumble onto a bat roost and find a way of setting up a camera close by.)

When I went through my Birdcam's most recent photographs I was very happy to find a few great photographs of bats. They were flying close to the ground amongst the thickets in the Woody Cape section of the Addo Elephant National Park.

Egyptian/Common Slit-Faced Bat (Egiptiese/Gewone Spleetneusvlermuis - Nycteris thebaica) flying in the thickets of the Woody Cape

The photographs are even good enough to identify the species! After spending hours going through my various field guides I managed to narrow it down to a handful of species, however I couldn't be sure... Then I noticed a picture in one of the books showing a forked tail! TA-DA!! As easy as that!

This is an Egyptian Slit-Faced Bat. As far as I know the forked tail is unique amongst mammals (being limited to this genus).

The photograph also nicely shows the elongated heel bone (aka the calcaneum) that helps support the tension in the tail.

I think this individual has the rare rufous coloration that is apparently more frequent encountered towards the eastern parts of its range. These images were photographed close to the coast in the Eastern Cape province of South Africa, which might explain the colour.

The stretch of thicket where the bat was photographed, with the small holiday town of Cannon Rocks in the distance

These bats have huge ears. They use echolocation for navigation and catching their prey, but they also rely heavily on the mechanical sounds emanating from the bugs to track them down. They prefer feeding on various forms of beetle and crawling critters, instead of the usual moths, mosquitoes, etc. Because of this they can often be found catching their prey on the ground. They also like to return to a feeding perch to finish the meal.

Catching something amongst the leaf litter

The Egyptian Slit-Faced Bat is a slow flier and this probably played a part in capturing these photographs. Their echolocation and good maneuverability allows them to navigate and hunt in the thick vegetation at night.

I'm not sure but I think the photograph below shows the bat either in the process of snatching up some dinner, or maybe it is carrying something it caught amongst the leaf litter in its mouth to a feeding perch close by.

I think this might be one of the more handsome species compared to some of the craziness found in other bat species

All in all I think these are some great photographs from the Birdcam. This is only my second round with this camera, and although it definitely has some flaws, it does seem to be able to produce some very pleasant surprises.

12 comments:

  1. WOW Henry - those are great! I'm looking forward to seeing more images from your Birdcams

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  2. Great find, together with neat natural history observations. Congratulations on a new first.

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  3. Great shots Henry. Fantastic sleuthing to be able to key them out to species from just a couple of images. You really captured some good behavior there too.

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  4. Fascinating bat pics, well done! Also great that you included lots of interesting info and the wide view of the bat's habitat. I always enjoy your blog, thanks so much!

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  5. First time I visit your blog.
    I have to say you really share some absolutely uncommon shots.
    These ones from the Bat are great!
    Bye.

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  6. Thanks for all the comments :)

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  7. You have some great shots here especially the bats-I have just bought a camera trap and and have had very little success other than domestic cats and the occasional blurred shots of bats-your photos have made me realise that possibly everything comes to he who waits and has patience!(along with a lot of field craft and knowledge of course!)

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  8. Fascinating pictures! Would you them as a citizen-science observation to the AfriBats project on iNaturalist?:
    www.inaturalist.org/projects/afribats

    If you decide to share your pictures, please locate your observation on iNaturalist as precisely as possible to maximise the scientific value of your records.

    Many thanks!

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  9. @Paul: Yes patience is the key! I always say camera trapping must be one of the most frustrating hobbies out there, but if you keep at it then it can be very interesting and exciting.

    @AfriBats: Sure thing, I have the GPS location somewhere, I just have to find it. (I'm, very far behind with my data capturing...)

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  10. That's great, Henry, I'm looking forward to your contribution on AfriBats!

    A few remarks: your ID is correct, the bat is a Nycteris thebaica.

    Slit-faced bats forage close to the ground by "gleaning", i.e. by passively listening to prey-generated sound rather than detecting their prey by echolocation (thus their large ears). Rustling noises produced by arthropods such as beetles or scorpions are detected while flying close to the ground, and the bat dashes to the source of the sound where it covers its prey with its wings and tail membrane. Your sequence seems to capture just such a hunting event, and if I'm not mistaken, the last picture shows the bat carrying a large, black arthropod in its mouth.

    Is this maximum resolution, or would you pictures with higher resolution?

    Re location: when adding your observation on iNaturalist, you can use the mapping tool to zoom into the approximate area where the pictures where taken, and adjust co-ordinates at a later stage.

    Cheers, Jakob

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  11. Welcome to AfriBats, Henry! On iNaturalist, please add your pictures (go to "Edit" where you can select one or multiple pictures from your hard drive), which could be accompanied by the habitat picture.

    Under "Description", you could add your text of the blog entry, or include a link back to your blog with your observation.

    Cheers!

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  12. One final comment: please consider adding the other pictures as well (you can add several per observation) since iNaturalist is a repository for these kinds of observations with a long-term perspective, so uploading them there in addition to your blog would make sure that they are maintained even if you decide to delete your blog.

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