This seems to be the week for surprises on Roundtop Mtn. The butterfly in today’s photo is, I believe, what is euphemistically referred to as a red-spotted admiral. A red-spotted admiral isn’t a true species, it’s a hybrid between a red-spotted purple butterfly and a white admiral. I happen to live in a fairly wide geographic band where the two interbreed.

Hybridization isn’t the only interesting feature of this butterfly. It’s also a mimic. Several swallowtail species and the red-spotted purple butterfly are among at least 6 species identified so far as those that mimic the appearance of the pipevine swallowtail. Pipevines are poisonous butterflies. The red-spotted purple is not. But by mimicking the appearance of the poisonous butterfly, the purple hopes predators will think it is poisonous, too.

For me, this is simply a beautiful butterfly that was calm enough to sit still long enough for me to snap a photo. I enjoy finding out about the things I see on the mountain, but really, I’d think I’d enjoy its beauty just as much even if I didn’t know all that about it.