Jerry Coyne posted today the video from which this GIF was made, and it’s incredible:
[A] group of researchers from the U.S. and Colombia have discovered a bird in Peru whose nestlings (but not the adults) are not only brightly colored, but appear to have both the appearance and behavior of a toxic caterpillar that lives in the area.
After the nestling was first observed, it was predicted that a toxic caterpillar resembling the nestling must exist nearby. And now it’s been found, say the researchers:
“The caterpillar we encountered measured 12 cm, which closely matches the size of the L. hypopyrra nestling (14 cm during the first 14 days); but the striking morphological similarity is the caterpillar’s orange “hairs” with white tips, which match almost exactly the nestling’s elongated orange downy feather barbs with bright white tips. The morphological appearance of an aposematic caterpillar was reinforced by behavior: the caterpillar-like head movements of nestlings (when disturbed) closely resembles the movements of the aposematic caterpillar.”
What a wonderful thing. (A commenter at Imgur wryly wonders how we know it’s not the other way around — maybe the caterpillar is mimicking a baby bird so birds won’t eat it.)