Caterpillar of the Eastern Tiger Swallowtail
I’ve been so busy writing other stuff (proposals and manuscripts) that I haven’t had time to post many pictures lately. That also means I haven’t been out much to take new pictures. So here are some photos from a couple weeks ago – a caterpillar that belongs to one of the species of swallowtail butterfly – probably the Eastern Tiger Swallowtail (I also posted a photo of the adult for this species below).
The “eyes” that you see are not actually eyes at all. Instead this is a type of cryptic coloration (specifically mimicry) that has evolved to look like eyes as a defense mechanism.

Eastern Tiger Swallowtail Caterpillar. The eye spots seen above are a type of defense mechanism using cryptic coloration. The real eyes are two bluish-grey objects below.