[2][3] The egg clutches are deposited on the shoot tips of the California pipevine, a perennial vine native to riparian, chaparral, and woodland ecosystems of the California Coast Ranges, Sacramento Valley, and Sierra Nevada foothills.

The larvae feed exclusively on the foliage and shoot tips of the pipevine, although adults eat floral nectar from a variety of plants.

The larvae sequester the toxin, and both the juvenile and adult butterflies have high and toxic concentrations of the aristolochic acid in their tissues.

Throughout the range of the species, Battus philenor, other butterflies and moths mimic the distinctive coloration of the swallowtail to avoid predators.

[8] The species' presence was drastically reduced in San Francisco, but was being brought back as of 2017, through efforts mainly attributed to Tim Wong, an aquatic biologist at the California Academy of Sciences.