I always get a kick out of seeing geckos everywhere, even after all these years. In Thailand, you can see Common House Geckos,
Hemidactylus frenatus, just about everywhere you look. Mostly, they are running up walls and getting out of sight.
On a tree by the bus stop at the front of the village where my school is, I am often lucky to get to see one close-up hanging out there. I always get a kick out of how well they match the tree bark. They look like the texture of lichens growing on bark, and they can vary their coloration to match the general background color. Here are several pictures of this.
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| You may recognize this from above |
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| The dangers of moving from light to dark backgrounds. Notice the tail still blends really well. |
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| From a different angle with different contrast, it blends in better |
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| If this one hadn't moved, I probably would not have seen it at all |
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| Nearly blended with the area to the left |
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| A near perfect match |
As for why this or these geckos frequent this tree, there seems to also be a colony of Singapore Ants,
Monomorium destructor, occupying the tree as well (there is always a line leading to cracks and what appear to be bore holes, presumably where the colony is located).
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| Close-up of Singapore Ants using the Olloclip Macro |
If the geckos are eating these, then it would be a nearly constant, reliable food source.
Oddly, I cannot find any good research papers about the mechanisms or evolution of their color changing ability. As for the pattern, regular variation plus natural selection would easily mould variable spots and lines into the lichens-on-bark (or pebbles on sand, in a different background) pattern we see.
A rather simple, common thing to see, but no less awesome for that.
