This piece, from nerdist. com, describes one of the more amazing cases of mimicry I’ve seen. Look at the picture below, and see what you think it is:
It’s not a snake, despite the very snake-y appearance of the thing. It has eyes (fake), the eyes even have a “glint” in them (fake), it has a fake mouth, and even fake “scales”.
It’s from Trinidad, and it’s one of the life stages of a lepidopteran. In fact, it’s the pupal case of the Daring-Owl butterfly Dynastor darius darius, a subspecies from Trinidad (the species D. darius is found in Central and South America).
Here’s a picture of an adult of another subspecies, D. darius stygianus:
It’s when this caterpillar becomes a pupa that it turns into a snake mimic, and the mimicry, as you can see above, is amazing. Here are a few more photos:
This is what the predator would see. Look at those eyes!
Now remember that the pupa is stuck in one place, which raises the question of why it mimics a snake. After all, a potential predator (likely a bird) inspecting the pupa might discover that it can’t move, and then nom it. But, as the article notes, the selective advantage of mimicking a snake doesn’t require movement or the ability to escape a predator once you’ve been spotted. The predator, seeing what looks like a snake, could simply flee without closer inspection.
But there’s more, for the pupa apparently can move—violently—when disturbed. A 1978 paper in Psyche by Annette Aiello and Bob Silberglied reports this in a few tantalizing words:
For 13 days, D. darius destroys and reforms itself inside what looks like the head of a Gaboon pit viper (though the snakes aren’t native to Trinidad).