Similar Species: Western Tiger Swallowtail, (Papilio rutulus). Western Tiger may appear yellow with black while Pale appears black and white. Also the black stripes on the Pale are thicker and deeper.
Habitats, Behavior: The Pale Swallowtail is most often found flying along undisturbed water courses or in moist canyon areas. More often in the Mountains.
Larval Foodplants: Redberry (Rhamnus crocea), California Coffeeberry (Rhamnus californica), California lilac (Ceanothus spp.), and Holly-leafed Cherry (Prunus ilicifolia)
Nectar Plants include: Thistle