“Eye of newt and toe of frog..”

Time for something less warm and cuddly, I think.

I see surprisingly few reptiles or amphibians in South Luangwa, but they are around. My grand total was one snake (Spotted Bush Snake, too high and too fast to catch or photograph), one terrapin, one frog’s nest, and two lizards.

Today, the lizards.  An easy one is is the tropical house gecko, (Hemidactylus mabouia), living happily in my hut, and helping keep the bug population down:

Bibron's Gecko

Geckos have this amazing ability to hold on to vertical surfaces, and this close-up of the feet allows you to, just, see the toe pads (and the non-retractable claws).

Bibron's Gecko

“.. their bulbous toes are covered in hundreds of tiny microscopic hairs called setae. Each seta splits off into hundreds of even smaller bristles called spatulae. .. the tufts of tiny hairs get so close to the contours in walls and ceilings that van der Waals force kicks in. This type of physical bond happens when electrons from the gecko hair molecules and electrons from the wall molecules interact with each other and create an electromagnetic attraction.”  https://www.livescience.com/47307-how-geckos-stick-and-unstick-feet.html

Nocturnal species of gecko also have extraordinary eyes.

Bibron's Gecko

They have multifocal eyes, and even in very very low light they can still see color through their large round pupils.  In higher light intensities, the pupils begin to narrow to a vertical slit with only a few pinhole openings in them. In the shot above, the gecko’s top (left) eye is between these two extremes as it adjusts to the light of my head torch. The bottom (right) eye is in shadow, and the pupil is much much larger and rounder. The graph below is from a paper on the helmet gecko, by Roth et al (2009), showing (from left to right) how pupil area decreases by a factor of 150 (compared to a factor of 16 in humans) as light intensity increases (the scales on the graph are logarithmic):

 

gecko-eyes.jpg

 

The second lizard I saw was a skink, probably a Tree Skink (Mabuya planifrons), but I am not quite confident of that!

Variable or side-striped skink?

 

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