Largest butterfly in the US and Canada, up to 5 inches in wingspan. Wings dark brown to black above, with pale to bright yellow spots in rows aligned to border the wings. Each tail has a yellow eyespot, and there are blue and orange spots on the inner side of each hindwing. Underneath, the wings are yellow, with black, blue, and orange markings (detail, lower left). Body is yellow with a black back, black eyes, and black antennae. Takes nectar from many flowers.

Caterpillar is camouflaged as bird poop, brown with cream to white markings. If camouflage doesn't work, it will erect its bright red forked horn (osmeterium) to startle would-be predators (see lowest row). The osmeterium also emits a foul odor to further discourage attention. Caterpillar feeds on members of the citrus family, which makes it an agricultural pest in orange-growing regions. In Wildwood, it presumably feeds on hoptrees.

Beautiful native of the eastern US down into northern South America. Occasional in the Park.

The large size and wing pattern are distinctive. Thoas swallowtail (P. thoas) is similar, but western. Other swallowtail caterpillars also look like bird poop when very young, but large animated poop is most likely this species.

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