These Buff Tip moths that I caught last night together with a poster on crypsis that I was reading yesterday have prompted this post.
There are many strategies that animals use for camouflage but they really fall into two categories: mimesis and crypsis. Crypsis is general blending in with the background in various ways and eliminating (or making it hard) to see outlines and shadows. Things like military camouflage with disruptive patterns make it hard to see a clear outline and this spot the wearer whereas species like Great White Sharks are pale below and dark above such that they are hard to pick out against the darkness of the depths or the light of the sky. Lots of animals use this strategy.
Mimesis is pretending to be something else. Some examples are rather clear as with Pygmy Seahorses but some are a little harder to work out. Here is one of the Buff Tips from last night.
Ok, it looks a bit like a twig but what is with the bright spot? The clue is in that little broken knot in the twig and becomes clearer if you look from the front.
The moth is mimicking a broken twig such that it can sit still on a twig and blend in. Notice that around the pale area, there is an obvious double line which looks like the ring of bark and that the pale area is quite textured again following the non clean break of the twig. This whole accessory is not actually the head but a structure above it.
Nature is pretty cool sometimes!