Pipevine Swallowtail

I've been driving around South-eastern Arizona for the past few days.  From time to time, large black butterflies fluttered across my path.

Today I managed a quick photo.

Pipevine Swallowtail  (Battus philenor)

Wikipedia says this:

The Pipevine Swallowtail (Battus philenor) is a swallowtail butterfly found in North and Central America. The butterflies are black with iridescent blue hind wings. They are found in many different habitats, but are most commonly found in forests. The black or red caterpillars feed on Aristolochia species, making them poisonous as both larvae and adults, while the adults feed on the nectar of a variety of flowers.

 More info at:
http://www.butterfliesandmoths.org/species/Battus-philenor

http://bugguide.net/node/view/412