Best mimicry ever

August 31, 2013 • 11:58 am

From Real Monstrosities via Ed Yong via Matthew Cobb comes one of the best cases of mimicry I’ve ever seen. Natural selection has been a fantastic artist here, giving a perfect illusion of three-dimensionality. In fact, this may be the most astonishing case of mimicry I know.

It’s a moth from eastern Asia: Uropyia meticulodina—a fantastic dead-leaf mimic:

uropyia_meticulodina
Image: Bettaman via Flickr

As the RM site notes:

It’s not just brown like a dead leaf, it’s brown like a curled up, dead leaf.

And it’s not just brown like a curled up, dead leaf, it depicts a leaf catching the light, with shadows in all the right places and you can even see the veins casting tiny shadows along the curled underside. It’s like one of those optical illusions that still work even when you know it’s a trick.

dead_leaf_moth
Image: enyagene via Flickr

Here are two videos of the beast.  The most amazing part of this illusion, which you’ll see below, is that the wings aren’t curled at all—they’re flat!

In slow motion:

It’s all done with color and shading: nature’s smoke and mirrors.

33 thoughts on “Best mimicry ever

  1. I had to watch the videos before my eyes and brain would accept the flat wings…harder to distiguish than most optical illusions I have seen.

  2. There’s an important point here.

    There’s little or no value to this moth fooling us with its mimicry. Presumably, the benefit is in fooling its natural enemies (birds, I presume). So this gives us evidence that birds (or whatever) are subject to the same sort of optical illusion as affects us.

    1. Yes, that’s a good point, and one that I make in my lectures on mimicry. It shows that bird vision must be similar to ours, and also that they see colors. We would know that even if we knew very little about bird vision, if we simply knew that they were the main predators on these moths.

      1. A possible corollary : IIRC, birds have visual pigments with slightly different sensitivity peaks than humans so one would hypothesis that if you could filter the videos / still pictures appropriately to give humans a “birds eye view” (which probably means breaking down the image into it’s RGB channels, then scaling them and re-printing ; it’s probably not terribly difficult to do for either still or video, but I don’t know the terminology), then the mimicry would be better. And that should be amenable to fairly simple “how long does it take for the student to spot the [mimic]? experiments.
        Or have generations of biology students already done this sort of experiment for their theses?

        1. Same lighting problem ; different approach
          I took a dive’s worth of photos a couple of years ago without adjusting the “white balance” of my camera to match the changed light at 15m. I’m sure that I can correct the photos but I’ve still not figured out how. I really ought to get back at the problem, and write a how-to.

        2. Unfortunately, I don’t think it’s as simple as playing with the pixels in existing images. Evidently many birds are tetrachromats (have 4 kinds of color sensors, as opposed to non-colorblind humans having RGB), with some of the spectral response extending into the ultraviolet (http://en.wikipedia.org/wiki/Tetrachromacy). So images taken with a normal camera that doesn’t respond to ultraviolet light just can’t be manipulated to show what a bird would really see; you’d need a special tetrachromat camera.

    2. Interesting point. I’ve often wondered how other animals perceive the world, and even whether that sentience may extend to forms of “appreciation”. It’s a stretch but some birds have immaculately detailed nests and am always blown away at how elaborate male birds of paradise look – maybe the opposite sex is responding to a nominal value like size of a plume but certainly makes one wonder whether there is also in their brains some measure of higher aesthetics.
      (Maybe it’s just me but I looked at the moth pic repeatedly and I still can’t believe the wing is flat)

      1. So far as I can tell, that infographic is mostly wrong, with a few accurate bits of information thrown in for variety. E.g., most snakes do not have heat-sensing pit organs and just about everything about that human vs. daytime snake vs. nighttime snake illustration is incoherent and wrong even for the minority of snakes that do have pit organs.

        1. Good example of informative substance taking a long second place to some graphic designer’s idea of style.

  3. Just WOW! That is so totally and utterly awesome.

    But let’s suppose that God did it.

    He created this mind-blowing camouflage deliberately to enable the moth to deceive predators which He created with appropriately deceivable vision.

    How bizarre is such a God? Why would He want to do that?

    That a mindless process of blind mutation and natural selection can do what such a God can do is not at all bizarre but is breathtakingly wonderful.

  4. I wonder whether the moth orients its body while resting such that the light comes from the back; this then would match the “shading” in the front, and the “glare of the light” at the rear. If so, then both morphology and behavior are modified to fool the predators.

    Many other leaf-mimicking moths, katydids, mantids, etc. fool their predators by rocking as if the “leaf” is moved by wind.

    Testing this orientation behavior to light by this moth should be a very simple undergrad project.

    Any such evolutionary modification of the behavior (orient while resting such that the rear points towards the light) would also mean that the predators can interpret shading correctly in the context of the directionality of the light, such that the predators exert the selection pressure to shape the bahavioral adaptation.

  5. Holy crap! I was wondering how it flew with wings all curled up like that, I thought they must uncurl first which seemed weird. This is fantastic!

  6. Damn, that is good looking. I suspect this’ll be a favorite with ID people, since it’s a lot easier to show people than bacterial motors.

    Heck, I’m not entirely convinced myself it isn’t a hoax, and that it might actually be a product of intelligent design.

    Although, even if it is, points for getting the moth to behave well enough to paint it. Whether the artist was man or nature, it’s no mean feat.

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