Pipevine Swallowtails, Battus philenor

I wasn’t sure what was waving like a flag on a grass stalk in the prairie this morning. On closer inspection I found these two Butterflies mating. That’s a first for me.

Thanks to Donna Brunet for help with the ID! I was sure this was a Spicebush Swallowtails but she pointed out that Pipevine Swallowtails have a single row of red-orange spots. Spicebush Swallowtails have 2 rows.